Hello People, I would like to know how I can INCREASE the FULL- THROTTLE RPM. Setting. My 5HP. Briggs snow blower seems to strain with removing heavy snow... 6 inches or more. When I over-ride the governor momentarly [go to wot], I noticed that the governor control holds the engine back to apx. 1/2 throttle. I believe there may be a weak spring, or something that can be adjusted. Please, advise and provide pics, Thank-You, Nitro-btu.

Hi,
If it is a Briggs, then it is right behind the governor plate below the gas tank

Make sure that whatever the governor linkage attaches to on the carb is totally free. Use carb cleaner.

Hi,
Beneath the fuel tank and behind the bottom bracket that fastens the tank to the lower block is kindof "U" shaped piece that one end of the governor spring attaches to. With the control at WOT the spring should be almost vertical and the aforementioned piece should be at the bottom. Taking some appropriate tool and bending that piece downward, so as to put more tension on the spring will increase the speed.
Peace,
Clarke

Hi,
Beneath the fuel tank and behind the bottom bracket that fastens the tank to the lower block is kindof "U" shaped piece that one end of the governor spring attaches to. With the control at WOT the spring should be almost vertical and the aforementioned piece should be at the bottom. Taking some appropriate tool and bending that piece downward, so as to put more tension on the spring will increase the speed.
Peace,
Clarke

Thank-You, crigby. I will try the above mentioned procedure, and post the results when I get a chance. Jim.

Crigby, As you said, the spring at WOT is Vertical, and at Idle almost horizontal. However, rather than bend the tab to increase tension on the spring. I believe, I can pull up another loop on the spring [making it 1 loop shorter] to increase the tension. What do you think of that? Jim.

Hi,
You can but you stand also the chance of modifying the springs tension. With the Model and Type nos. off the engine you can look up a spring with more tension at the Briggs website; they will be item #209 and will reference the top-no-load speed it is rated at.
Peace,
Clarke

Crigby, I bent the u shaped tab down to increase spring tension. What I found by doing this, actually caused the engine to run lean near WOT. So lean that it would not run @ what, and the exhaust was cherry red.
The only way this might work is to change the brass main jet to a Larger size. Will... the fuel pump be able to pump enough gas to richen it @ WOT, and when at idle it may be to rich to run, or[idle] ? I was only trying to Maximize the engine's potential, but it appears that has already been done through Engineering.
What do you think of my Discovery? Jim.

Hi,
This is not how the engines are normally designed. Increasing the speed should not be a mixture-affected event.
Carbs are designed with four basic circuit characteristics; first is the pilot circuit which does the work to 1/8 throttle, second is the first intermediary circuit that does the job from 1/8 to 1/4 throttle, third is the second intermediary circuit which does the job to 3/4 throttle where the main jet takes over. This is a simplified picture of the engineering process of the carb. Not all circuits must be discrete, obvious or independent. There is always a transitional overlap of one to another in a well-performing engine.
The jist of that is a larger main will not be noticed by a pilot circuit.
Got any numbers off the engine? Manuals(service) are to find online, but I have read them for thirty-odd years already.
Peace,
Clarke

HERE ARE THE NUMBERS... 130292... 1061 02... 80090806... I already know about the carb circuits, ran engine dyno for Ford's. This carb has only one needle valve, and it meters gas flow through the main jet. So, I believe in this case that the idle will be affected by a larger jet. Turning this needle from its normal 1 1/2 turns out setting has effected the lean/rich mixture through all RPM. Ranges.
Secondly, I believe there is a small air leak somewhere in the carb, because the engine wiil not start COLD with the choke on. Rather, I have to prime it through the choke... then choke it to start. After it warms up... it will start without a prime. I do believe this condition has something to do with the Lean A/F Condition Near WOT. Also, the carb has been soaked/cleaned, and has a new fuel pump diaphram with spring, and cap. Please, evulate this additional info... and see if you can pin-point the problem.
Thanks again, Jim.

Hi,
I agree with your assessment of the lean running condition. I agree with the air leak conclusion, also.
The 299060 jet assembly is actually two jets in one assembly(one fixed and one adjusable) mating into one unit. The adjustable one controls most characteristics of mixture.
Just a question, when you replaced the diaphragm, where did you install the cap? It prevents the end of the spring from abrading a hole through the diaphragm(an air leak possibility.)
Barring that, try cranking the engine, warming it up and changing the mixture characteristics with some form of spray(needs to be flammable) to see at what place the engine operation changes. Could be carb cleaner, WD40, brake cleaner(flammable.) When it hits the leak, the RPMs should change as the mixture has richened.
You could be unfortunate and have a porous carb body that the cleaning revealed(rare with zinc carbs, but not unheard of) and require a replacement carb. Think I would look for a used one since your engine was made Sept. 06, 1980.
Peace,
Clarke

Hi,
Got to thinking about that answer, and I misspoke. You are right beside the muffler and should NOT use a flammable liquid spray to check for air leaks. They are so handy because the engine can burn them, just change running characteristics. The nonflammable sprays work, but can cause repeated needs to recrank engine. Some that will not harm the engine would be some of the sprays available to loosen rusty or stuck fasteners and some types of brake cleaners. The label will say.
Peace,
Clarke

Hi,
BTW. The governor spring is a 260695. I have the parts manual if you would like it emailed to you.
Peace,
Clarke

Crigby, Very good point about where to put the cap with respect to the diaphram. Well I thought to protect the diaphram, it should go between the spring and diaphram, leaving the other end of the spring to butt up against the inside of the carb.
With respect to Air leaks, where would you think the most likely place could be with this type of carb ?
Yes, I would like the parts manual.. . Please E-mail it to... [email protected]

Thank-You, Jim.

Diaphram carb - the primer bulb

Hi,
Manual sent. Well, to look at it logically, there are a limited number of places that an air leak would have an effect(ie where air could enter and change the mixture of fuel and air adversely.) The carb is shaped roughly like a large cigar, but fuel does not enter the air stream until it reaches the location where that jet is. So, it would be between there and the engine block. It could leak at the pump cover(rare but I have seen them warp, or the diaphragm to accidentally get slightly folded, actually the go-kart racers used to do it on purpose - illegal, but hard to catch) or at the intake gaskets. Anywhere else but at the jet inself, there is an aluminum or fiber gasket there, would have to be in the body itself, and would mean carb replacement.
As an aside, since you say the carb was cleaned, that means the tank/carb were taken loose. It is easy to damage the governor spring when disconnecting it from the tank's throttle linkage. A practiced mechanic can loosen it without disturbing its location on the governor arm. When I was newer to the "game" that was not often the case. There are a number of holes in that arm and which one used affects the operation in some often unpredictable ways. The correct hole(s) are near the inverted "V" shaped notch in the arm. I will try to find a repair manual, though I have little success finding a Briggs(some Tecumseh and Kohler, yes) online.
Peace,
Clarke

HAVE ANY OF YOU PEOPLE HEARD OF "SEAFOAM FUEL SYSTEM CLEANER"? I have read up on the stuff, but I don't know if it Actually Works. I would like some direction here. Thanks, Jim.

Hi,
Never tried it myself, but it is the "darling" of the motorcycle world. Originally made in the 1940's as a cleaning additive for the boating industry(hence the name) it has found favor among many mechanics who deal with engines that have sat with fuel in them for extended periods.
It seems that about 8 oz. to a tank of fuel and run that through it. Add again on fill-up and run part through, then allow to sit a couple of days to attack the remaining varnish seems to be the best recommendation any of my biking friends could give me(I gave up bikes some years ago, except the pedal variety for exercise.)
The company makes three products. It can, and is promoted for, the cleaning of injectors. There is a transmission product, also.
Peace,
Clarke

HELLO THERE Crigby, It's been a year, and now I'm in the middle of another Winter Wonderland here in Mich. You might remember Some of my Questions regarding the 1980 5hp. Snow blower. Well, Increasing the governor spring tension, has made things worse, but I had to try it. Now, aside from that... ALL THE PRIOR PROBLEMS HAVE REOCCURED THIS YEAR AGAIN. The fuel last year, was Heavily treated with gumout type cleaners to Extreme... 4oz. Per. Gallon of gas. YES, It Ran Fine before putting it up for the season, and still had the same fuel into this year 2009.
Somehow the main fuel jet has another restriction, or is varnished up. I suggest, to Refresh your memory, Please go to: "WOT/Governor Control Speed," there are 2 pages.
Crigby, Please give me your take on this nightmare. Thanks, Jim.

Hi,
Have you tried checking the screens at the bottom of the pickup tubes? Older engines sometimes had the screen on the long one varnish over and affect the fuel mixture. About a decade before they had a problem with the long tube failing out of the body completely. Looking in through the gas cap opening would reveal that.
Peace,
Clarke

YES, When I cleaned/soaked the carb last year, I did replace the long plastic tube with a new one. There is one strange thing that I have noticed. It appears to run out of gas at a 1/3 tank level. Which may have something to do with the longer pick up tube. I put fresh gas in it the other day, but did not happen to check the tubes. If the long tube should happen to fall out, what would happen, what are the symptoms ? WOULD THE ENGINE RUN AT ALL ?
What about the increased governor spring tension, (I bent the tab) would that prevent the throttle from responding properly under load conditions? Thanks Again, Jim.

Hi,
If the tube falls out, the engine will run for 1/4 tank or less by the suction and splashing action, but the ones that fall out are brass. They had a replaceable end. Never seen a plastic one fall out.
Some plastic pickup tubes have a sort of check valve near the bottom. It will be visible through the side of the tube at the bottom. Will look like a sleeve with a seam rather than a valve.
As cheap as diaphragms are, I never fail to replace them often if any other service is done.
I have never seen a larger jet for that particular carb, but it is possible that some go-carting site offers them. Most of those engines other than the outlaw class have to comply with some very strict requirements and restrictions. Most will have far newer versions of all parts because of the lifespan expectation being exceedingly short.
Peace,
Clarke

Clarke, I don't know about the engine running for a 1/4 tank of fuel due to suction, and splashing action.. . That seems a bit of a STREECCH ! If that were the case, then that fuel pump diaphram is "Golden."
What do you think about drilling out the main jet a "few thousandths larger?" Also, what about the governor spring tension? Thanks, Jim.

Hi,
Saw the 1/4 tank thing on Sensation roll-around blowers in the 1980's when the brass tubes would fall out.
The tool I have used on jets was the tip cleaning tool for oxy-acetylene torches to clean them. It is a bunch of almost little rod files of graduated sizes.
I would get the carb to work before worrying about the governor too much. Unless it is way off, it is the secondary issue.
Peace,
Clarke

Clarke, I need to know Exactly what problems low cylinder compression can cause. For Example, figuring everything else is working properly. (1) With the engine hot, or cold... it must be primed through carb choke, or through spark plug hole, in order to Start it. (2) When running hot, or cold Never really know what to expect... sometimes it runs best with choke closed, and other times it Must be just Cracked open a 1/8." VERY SPORATIC / UNPREDICTABLE ENGINE PERFORMANCE. (3) Then just when it stabilizes, and plows through the heavy snow... 5 minutes. Later it acts as if it's Running out of Gas, and Dies. (4) It will not start after this until it cools down. I have eliminated the ign. Coil, because if the engine is not under load, most of the time, it will run until out of gas.
Last year I put some carb cleaner in the tank, and ran it at fast idle for two hrs. with no problem.
Please, take your time, and evulate All of the above problem info. Then through the numbers, Try and make Sense of this NIGHTMARE.
Again - Many Thanks, Jim.

1) Means fuel related
2) Fuel related
3) Fuel related - probably flooding (remove spark plug and inspect for wetness)
4) Fuel related - Too much gas is vaporizing because of a hot engine - again check plug as in#3

If you suspect compression, do a compression test with and without some oil in the cylinder.

Do we have any sort of smoke colors like white or blue at any point?

"CALLING - ALL ENGINEERS," I agree it has to do with fuel, but I need Some SPECIFICS ! What part of the carb is Faulty to cause this sporatic behavior. EXAMPLE: WHILE ITS RUNNING WITH POWER... its plowing the snow, then out of the Clear Blue... IT FLOODS? "WHY?" What Change takes place to Cause this Flooding ? Does it have anything to do with the Governor ?
Also, I haven't noticed any smoke colors - blue, or white, but there have been Sparks on occasion with Backfiring.
COME ON CLARKE - Take a shot at this. Thanks, Jim.

Four things in particular come to mind:

One is governor related. Make SURE that the gizmo on the carb that controls the throttle is totally free. The governor has to be able to move it with little effort. Clean with carb cleaner if it isn't.

The second is a sticking fuel valve.

The third is something like a piece of rust in the fuel line, but that occurs if the tank is metal.

The fourth is a blocked gas tank vent on the cap.

Fifth is a plugged internal port. I hated that in a 1982 carbed Totota. About 120 parts to rebuild it and drill out some caps. Carb worked, but I had to take off the top and tighen the fuel valve assembly.


An aside.

You could check the compression when the engine is cold and hot.

On pg.#1 / post #10 are the engine numbers. Numbers 2, and 3 Don't apply. The Governor - I believe by resetting the bent tab to its original position, that it's OK. Throttle does move very freely with No binding. Last year, I replaced the gas cap.
My best guess is that there is either a massive internal restriction Causing a Lean Fuel condition, or massive air leak in the carb.
Why else, with a full-choked engine would it run with power to plow snow, If there Wasn't a Massive internal Air Leak in the carb ?
HOWEVER, The flip-side of this Nightmare... Having an internal restriction within the carb body, Would Definitely cause a lean fuel condition ! EITHER OF THE ABOVE Scenarios would bring about the same effect. Lastly, when fully hot, the engine runs with the choke Cracked Open 1/8" for Maximum Power, or 7/8" CLOSED !

Again - Calling on ALL Engineers. Thanks, Jim.

" IT APPEARS that the VERY BEST are stumped by this SPORATIC Engine Non-performance !"

Hi,
Well you said that it could run correctly with no load? Engines with a marginal ignition can do that. I have run three tanks of fuel through machines and done other tests without problems when not loaded. I have even had to seal off the discharge of a rider deck, engaged it and used a garden hose delivering a stream of water under it to load it enough to produce a failure.
As far as compression goes, the manual says to spin the flywheel backwards by hand toward compression and look for a minimum 90 degree bounce back.
I have found manuals online finally, though I cannot say they will remain available. See:
http://www.mymowerparts.com/pdf/Briggs%20&%20Stratton%20Service%20and%20Repair%20Manuals%20S pec%20Charts/270962%20Single%20Cylinder%20L-Head%20BRIGGS%20&%20STRATTON.pdf
Peace,
Clarke

Clarke, I Will at this point... buy a compression tester, to find out for sure. I would use the roll-back 90 deg. Method, but the drive end is enclosed. However, I can tell you that when cold, the resistance to compression when pulling the starter cord slowly is weak. Normally, you can easily feel the resistance when approaching TDC on an engine with Good compression.
Would you happen to know what the compression should be on a good reading ? How do I go about taking this reading ? FOR Example: Should I pull fast, and take each reading on the gauge for 10 pulls, then average, and then 10 slow pulls ? What's the Procedure ?
Thanks, Jim.

Modern engines have a "compression release" system. In the Briggs engine moving the flywheel backwards disables that system.

If anything, your looking at compression with a cold and hot engine. And compression with and without oil injected.

Pulling in the correct direction will get you nowhere because of the "compression release system".

Take the blower housing off and spin the flywheel manually, backwards. Fast doesn't mean anything either.

Think about how a compression gage works. It may consist of something tat threads into the spark plug hole and sometimes it contains two different sized threads and seald with an "O" ring.

There is a check valve on the gage, so it registers the highes compression and there is a release port. Usually a schrader valve that you push with your finger before removing the contraption.

It doesn't matter how fast it turns. The same amount of air gets compressed regardless. The gage registers the maximum PSI.

Hi,
I said to try the "bounce-back" technique not only because it is in the manual, but because of the reason it is in the manual. Most current engines use an ACR which disengages at running speed. Older Briggs engines have "Easy Spin" systems which mean the exhaust valve opens slightly on the compression stroke. It becomes mostly moot at higher RPMs, but never stops no matter the speed. My suggestion would be to pull the carb, head, breather and valve springs. Check the valve clearance; sounds as if you have too little. This will affect the pulse charge that affects the fuel pump on the carb. I will attach the link to the chart, yours is the 130000 and notice no compression reading is given! See:
http://www.mymowerparts.com/pdf/Briggs%20&%20Stratton%20Service%20and%20Repair%20Manuals%20S pec%20Charts/COMMON%20SPECIFICATIONS%20FOR%20BRIGGS%20&%20STRATTON%20ALL%20SINGLE%20CYLINDER%20L%20HEAD%2 0ENGINE%20MODELS%20270962.pdf
Peace,
Clarke

Clarke, I really do appreciate all the technical stuff, and am moved by it. However, there must be an Overall Miminum cylinder compression PSI. for this engine, whatever it happens to be. Will the engine Run with less than 60 psi ?
I believe the valves need lapping, as well as an adjustment.
Again, Please give me your take on this.
Thanks, Jim.

I found this online: Briggs and Stratton Small Engine Fault Diagnosis (http://www.westongm.eclipse.co.uk/Diagnosis.html)

It offers a quick "compression check" without a gage.

Reading through the rich, and lean probable causes, I noted that a defective/bad fuel pump diaphram may cause a rich, or possible a flooding condition. To the contrary, if there were a hole, and, or a tear in it, Wouldn't it simply "Fail to pump fuel?"
Also, noted with the "lack of sufficient compression," no fuel can be drawn in for combustion.
WHY are there No compression specs. For these engines ?
Give me your Best guess, as to what the compression should be for this engine, from min. to max.
Thanks, Jim.

Hi,
A "healthy" Easy Spin engine cranked at about 900 RPM should have about 65-90 psi. That RPM generally requires an electric starter since recoil/hand starting only produces 600-650 RPM at the best.
Briggs says it is not reliable even then.
A fuel pump with a pin hole will usually just not pump well. An engine down on compression will work the breather less because it will not have to compensate for the amount of ring blow-by that a healthy engine produces. Less blow-by, less pressure differentials that exist in the crankcase to operate the pump.
Peace,
Clarke

I'll tell you two fuel related true stories:

1. I was 15 YO and got my first car. Could not drive it, but it was wrecked when I got it. $25 for the car and it was mine. It had the darndest time working at full throttle. Found a slit in a small piece of fuel line at the tank facing UP. Pain to find. Eventually when I was all done, got 18 MPG on a 6 cyl carbed Ford with no emission controls. Added electronic ignition, ported the intake manifold and had the heads machined and rebuilt the carb at 15 YO. That was my second car carb. Rebuild.

My father had a car that would not go up this VERY STEEP HILL. I mean steep. Must be a 45 deg angle. Car would stall. We had to go around the hill. No real performance issues EXCEPT it could not go up STEEP hills. Fuel pressure turned out to be low and it was dx'ed as a bad fuel pump. The pump was taken apart. I loved to do that to just about anything. I found a check valve that popped out of a socket.

One other fuel pump story. I was driving many miles away and the car just died. It was the fuel pump. I had tools in the car. There was one stupid trick necessary to put the fuel pump on. Grease the actuating rod so it would not slip out of the engine. Ingeneous.


Maybe a defective fuel pump fits:

No power at high loads.
Always having to choke (means more fuel)
When hot a small amount of fuel will vaporize.

Did you ever check the plug for wetness after just cranking and no priming?

YES, I did, and found Absolutely NO-MOISTURE from fuel, or anything on the spark plug. The plug was dry as if it were sandblasted. Secondly, manually activated the throttle several times, and then cranked 8 times, and still nothing... IT'S BONE DRY! Yes, of course, the engine was fully choked both times.

OK.

1. Ignition - It doesn't exibit classic ignition problems - rule out ignition

2. Engine - No smoke, running rough etc. So except for compression release (do bounce back test) that would seem OK

3) Fuel (yep a fuel problem)
1. Compression - probably not (do bounce back test hot and cold engine)

2. Carb - The carb has various "systems". Loosely. Start, idle, run and power. They seem to run OK, not great. Carbs usually flood or no fuel or run very rough at some or all speeds.

2b. Fuel pump. In an older or even newer automobile, I'd measure the fuel rail pressure.

2c. Bowl vent/fuel cut solenoid if so equipped. Ususlly this is an on/off thing. It works or it doesn't.

Look at the fuel pump.

Hello, 2b, and 2c Don't apply.
The Briggs fuel pump on this 5hp. Pulsa-jet carb is internal, requiring only a diaphram, spring, and metal ring... for the spring.
When I talked about cranking it 8 times, I meant Manually pulling the starter rope that many times. No electric starter. Regards, Jim.

OK, so do the hat and cols bounce back test.

Cold engine:
Remove blower housing and turn flywheel backwards. It should find some resistance during compression and then let go. The flywheel should "bounce-back".

Hot engine:
Do the same.

Hello there, NOT to be Disrespectful, but this "Ballpark Test" is just that, and is used to determine whether a cold engine has enough compression to start.. . NO-MORE / NO-LESS. I am trying to determine the available power still left in the engine. Example: The Higher the compression readings, the Greater the power output. This Briggs Test is worthless when it comes to determining the available power output.
What-say-you, Of this ? Regards, Jim.

Clarke, Are you still with me ? I finally got through to a Service Tech, to discuss their "bounce back Procedure." Mark (the tech) himself told me the procedure was only intended to get you started, and that I should run a compression test. For my engine, he said after a couple pulls, the PSI. should be between 70, and 90. So, I did the test, and here are the results.
DRY CYL. BORE: 1pull.. 30 / 2pulls.. 40 / 3pulls.. 50 , and 4pulls 57. With a few more pulls MAX. IS 58
PSI. Then I shot 2 squirts of oil into the dry cyl, and tried it again.
WET CYL. BORE: 1pull.. 40 / 2pulls.. 50 / 3pulls.. 60 PSI, and this was MAX. THEN TO MAKE SURE THE RINGS WERE OIL SOAKED, I added two more squirts of oil, and rotated the engine a few times before taking the last set of readings. This reading Really surprised me... 1 PULL = 80 PSI. and the following 2 pulls DID NOT INCREASE THE 80 PSI.
ALL OF THESE READINGS WERE TAKEN WITH A "COLD ENGINE."
I believe, had the engine been warmed up first, the first set of readings probably would not have been so low. However, had it been hot would the last reading be Even Highier? You tell me, I don't know.
I asked Mark what could/would prevent the engine from starting cold, (without external priming) with the choke on. He mentioned two things: the fuel pump diaphram, and the crankcase breather tube. Either one, or Both could be at Fault. The latter is food for thought.
Well, That's the latest... PLEASE GIVE ME YOU THOUGHTS on this stuff. Again, Thanks, Jim.

Well, that's the classic test for bad rings. Compression improves dramatically when oil is used.

The test seems difinitive. Without compression there is no fuel.

I doubt a clogged oil breather applies here. You could always remove it for another compression test.

If this engine has overhead valves, you could try a valve adjustment.

What I'm implicitly implying is that the compression will be worse when the engine is hot.

The rings will be weaker.
The Cylinder walls may expand but not at the same rate as the piston. This would contribute to the near impossible starting when warm and the loss of power when warm.

Engines aren't hard to rebuild. Did my first when I was about 10 YO.

KISS, Can you Explain why there is NO-BLUE, or WHITE SMOKE coming out of the Exhaust, IF in-fact the Problem is Rings?

White is going to be coolant which you don't have.

Blue in a car, for instance usually comes at start up when the valve seals fail. You get a puff of blue.

When the rings fail, you burn oil.

You may not be at that stage yet. That's why I'm suggesting a compression test when warm.

KISS, There's no point in running a Hot compression test. The reason being, is that all readings would be relative to each other... Just Higher, or Lower. The only way the engine could burn oil is if both top compression rings are bad, or worn. After all, the oil has to pass through these 2 rings before exiting the exhaust valve. THEREFORE, Because there is NO BLUE SMOKE the two compression rings must be Good ! I don't believe the piston rings to be bad.
Now, possibly the valves may be the problem. At times the engine will backfire upon Rapid deceleration.
LASTLY, How do you account for the Power at times the engine puts out, to remove 6" to 8" of snow... Then all of a sudden for No apparent Reason the engine dies, as if it ran out of gas ? PISTON RINGS aren't Good one minute, and then bad the next, going from one extreme to the other. Rings simply Don't self-correct, So, I discard the rings as being the culprit. Rather, I focus on either the valves, or the carb. Possibly, the carb is so screwed-up, that it tends to over richen, or over lean the A/F mixture. A Long-shot, might be a condition called "Vapor Lock." Sometimes found in High performance vehicles. Regards, Jim.

The hot compression test is easy, so why not do it? Rings can not seal as the engine heats up which you said was a problem.

Backfires can be carb, timing or valve related. To rich of a mixture or messed up flywheel key. If they are overhead valves, check the valve clearance. Usually they are checked when the piston is at 1/4" below TDC on the compression stroke.

Check the flywheel key.


Carbs have internal passages and I had to rebuild one on one of my Toyota's that I owned because a piece of the aux fuel pump diaphram got stuck in it. Carb cleaner wouldn't touch it. It had to be soaked in the stuff that eats at the carb. And the passages blown out.

Do the easy stuff. You have a test that fails. A compression test with oil. No amount of oil will fix a valve that won't seat.

Poor compression means the fuel pump won't work right.

It's not the rings per say, but the ring seals over the temperature range.

Ahhh! I was trying to think about what the effect of a bad oil breather might be. It would increase the pressure in the crankcase which would impinge on the ability for the oil pump to do it's job resulting with poor piston ring sealing and lower compression especially after the engine warms up.

Again relatively easy, but not that easy.

Vapor lock should never be a problem with that carb. Poor tank venting could be.

KISS, The reason I mention valves, is because several years back when I didn't use this blower every year this became a problem. THEN... When I did need it, it wouldn't start. Well one of the guys at work had mentioned these engines, 5hp Briggs are natorious for "sticking intake valves." Sure enough he was correct. So, I removed the head, and took care of the stuck valve. First soaked the area thoroughly with liquid wrench, and then worked it free very carefully. Cleaned everything up, and reassembled. It seemed to run good as new; then a few years later the same problem. Corrected it again, and that's been it.
There is no oil pump, it's the splash system with a pointer attached to the bottom of the connecting rod to splash the oil.
Lastly, Briggs claims that a leaky exhaust valve will cause a lean fuel mixture, most notable at start, and idle, it dilutes the fuel mixture. So now both valves have become a potential problem.
WHAT SAY YOU - NOW ? Regards, Jim.

Well, then maybe it's your intermittant and fuel problem wrapped into one.

KISS, What do you Recommend ?
Scrap the engine, or try to lap the valves. Where can I get a Good used Carb for a reasonable price ?
Regards, Jim.

My initial thoughts (no order. Just thoughts):

1. Replace engine

2. Replace valves and seats. See http://aee.ag.uidaho.edu/default.aspx?pid=96166

3. Carb is going to cost about $80-$100 probably.

4. I's hate to put $ into a bad design unless I could improve it.

One can only hope that if this is a systemic problem that Briggs could have changed the design. It happened onec, so it may happen again with just replacing parts.

Taking things apart is more labor intensive, so it's possible to find a machine shop that will do it if the engine is stripped to the block.

It was a whole lot easier to drop off the heads of my car (to a neighbor who had a business) when I was 15 YO than to pay someone to do it. While they were being done, I ported the intakes.

TO WHOM IT MAY CONCERN:
Has anyone out there heard of Harbor Freight ?
Well, They have a replacement engine called the "Greyhound," and I'm trying to find out who makes it, probably a major company. It's a 6.5 hp. OHV design, Priced for about $100 bucks.
If any of you have this engine, Please give me your Feedback, whether Good, or Bad. Thank-You, Jim.

I have used a few of those engines on some of my customers equipment.
But I'll tell you like I tell them.
YOU GET WHAT YOU PAY FOR..

I have used a few of those engines on some of my customers equipment.
But I'll tell you like I tell them.
YOU GET WHAT YOU PAY FOR ..

SO, YOUR TELLING ME THEY ARE "TRASH?" Regards, Jim.

No what I'm saying is that they probably will not last as long as the factory one did.