[samuel adams]

Hi I have just purchaced a bob cat snow blower, and can't get it started. I have checked the spark, it appers to have spark, arcs on head. Have new plug. Shot starter fluid in plug hole. Not sure that was the right thing to do but Im not to smart on mechanics but I am trying. :-) full tank of gas. When I bought it It started just fine. The moter is an old (cant find a year on it) briggs & stratton 4 cycle 5 horse. #130 252. Would appriciate any advice. Thanks
Samuel Adams:-)

[crigby]

Hi,
Yes, it is old engine, That last set of digits will tell you the year in the format YYMMDDSS for year, month, day, shift.
At any rate you have a diaphragm on the side of the carb, muffler probably in the way. If the muffler bolts to the block, it is not too difficult. Remove it. There are four small slotted screws that hold the cover on. Beneath the cover is the diaphragm, cup and spring in that order, may not know the order if you let them just fall out. Get a replacement diaphragm and assemble spring in most, cup on spring( it keeps the spring from damaging the diaphragm), diaphragm and cover. There should be two pins roughly at 3 o'clock and 9 o'clock(cover is not actually round) that align the cover. Install your screws and then muffler and hopefully you will be running again.
Peace,
Clarke

[samuel adams]

Thanks crigby for the quick response. I will try that tomarrow when it's a little warmer and part stores may be open. Thanks again

[jjshameless]

Hey Sam Adams, any luck? I too have the same snowblower, will not start. Last season I could get it going with some quick start in the carb but now nothing. I took it apart and I have a hole in the diaphragm Clarke was talking about. I'm in a small Canadian town and not sure when I can get my hands on a replacement, let me know how it goes.

JJ

[samuel adams]

I just talked with the guy I bought the snow blower from. He said that the carb and all of the other components where just replaced. How ever I checked the spark plug and it was not giving good enough spark. I replaced the armature, (or the coil, wire, etc) and now it's the same as before. :confused: I wonder what I did wrong :eek: maybe I should stay away from engines.

[crigby]

Hi,
Just a thought! How is the compression? One thing that engine can do is have the intake valve stick on the stem of the valve in the guide. I have even had engines crank, run a few seconds(30-40) and do it. You can see it by removing the plug, looking in through the hole with a flashlight and see the valves. Pull the engine over slowly and make sure that they open and close. If the intake sticks, spray a good solvent in and use a screwdriver or similar object to pry it closed. Repeat several times until movement can be seen to be normal. Then try to crank. If it does, run at full speed for an extended period to get it up to operating temperature to clear the gum from the valve train.
Not saying it is it, just a thought!
Peace,
Clarke

[samuel adams]

Hi crigby. I had just recently had the cylinder head off and everything looks fine. I acually cleaned every thing. The compression feels fine, how ever, I will check it w/ my gauge. Thanks. It seems that I don't have any spark. Now I'm not a complete moron, I pay attention to what I am doing, I double check myself, but I still am not getting anywhere with this thing. I have now changed the armature-magnito, the breaker points-condenser set, the spark plug. However the plunger-breaker point is on back order. I am stumped. How many more possibilaties are there? The magnito came with a plunger-plug that does not look anything like the old one, and didn't really fit. I went back to the store with the part number on the instructions sheet, I thought that they made a mistake, and it was the same one. So I left the old one in. the parts store said they know which one it is and ordered it. The old one is shaped like an hour glass, and the one that came with the magnito is shaped like a cribbege peg. I don't really know what it does. Is it that important that I replace the old one. It was in bold lettering on the instructions sheet. It said it MUST be replaced if the breaker point cover is removed. Any thoughts on this would be greatly appriciated. Thanks:)

[crigby]

Hi,
Kind of wished you had asked, because I would have recommended tha you replace the armature with a solid state one if it was necessary. Works on all but the oldest of Briggs engines(three legs on the armature.) The plunger should be replaced and was #'ed 65704, but if points and everything need replacing then a 299061 ignition kit is the best way to go.
Okay, for all the "procedure" stuff. With blower housing, flywheel and breaker cover removed. Rotate the crankshaft in a clockwise direction until the points close completely. Keep rotating about 90º more to reach the setting point. There the gap will be set at 0.020" by loosing the clamp on the condensor and sliding it. Be careful to keep verything in a straight line so that the two contact surfaces meet flatly. Hope you are using "real" Briggs stuff here as I am not a big fan of the aftermarket stuff in this area! All that done, you are done under the breaker cover. If you you do not see any oil seepage at the plunger than it is probably okay.
Next to the armature, it will not work if mounted upside down. The wire that leads to the condenser should be on the back side(cylinder side.) It will not work otherwise, the magnetic fields do not build and crash correctly within the coil to create a spark.
Hope that helps!
Peace,
Clarke

[samuel adams]

Is it possible that I got a bad coil? I have had that thing apart enough times I could probably do it blind folded. Thanks for all your help. Do you know how the condenser system works? Mabie if I now more how it works I will be able to troubleshoot it better.
I really appreciate the help thank you very much.

[crigby]

Hi,
The magnets in the flywheel create a field in the coil that is amplified in the secondary windings within the coil. The condenser stores electrical energy that is released across the plug gap as the points open at approxiamately the time the field is changing by the passage of the magnets. That is a breaker system. Electronic ones are a bit different.
To another item, how many wire attach to the condenser? Two? If so, one is to the coil and the other to the ignition ground. Try disconnecting the ground to eliminate it, if so equipped.
Peace,
Clarke

[samuel adams]

Well I disconected the ground wire from the stop switch and still nothing. However just experementing with other possibilities I disconnected the little plastic spade terminal, on the back of the new armature, and spun the flywheel. I had the plug in my hand and ouch!! I was waiting to feel that shock all winter. I finally got spark. I put her back to gether and she runs like a top. The ground wire does not shut off the motor. I wired it so the stop swich shuts off the moter a little different, but it works. Don't quite understand why the wire attached to the back of the armature was not allowing a spark but, whatever works I guess. Thank you so much for your help, Merry Christmas and God bless. :)

[KISS]

This was a fun read. FWIW - No more starting fluid on small engines. Carb cleaner is to be used as starting fluid only.

You should try adjusting dual weber carbs or Holley Economaster carbs of yester year. Real fun.

[samuel adams]

Hay I got er going. The wiring was off. I unplugged the wiring harness on the back of the armature and she fired up. Thank you so much for your help. I appriciate it lots :D

[crigby]

Hi,
Good for you. Best of future luck!
Peace,
Clarke

[jjshameless]

Clarke, I've been following along with this post, I'm having the same problem, no spark. I replaced the plug, and the points and condenser(294628). Am I understanding you correctly that the plunger should move up and down when turning the crankshaft? This I guess is what makes the condenser make contact and release the voltage? Mine does not move, with quite a bit of force I got it out, looks like an hourglass, yes, tried cleaning it, but still a very snug fit, doesn't move when crankshaft rotated. Is the easiest thing to do now buy a plunge(65704) since I already have it apart and have replaced 294628? Jamie.

[KISS]

Plunger?

Points have to be gapped properly to work. The gap is usually set when the points are furthest open.

The Coil(Magneto) must not touch the flywheell. Probably no more than 3 index cards thick or about 0.010".

Actually, its when the points open, the energy stored in the condenser energizes the primary of the coil and poof, spark.

[crigby]

Hi,
I have always been in the habit of using the 299061 ignition kit since it contains a plunger and key. But, yes you should replace it if it does not move freely, should be able to hook your fingernail in the outside groove and remove it. Point gap is 0.020", magneto is 0.010" as stated and plug is 0.025-0.030"
Peace,
Clarke

[jjshameless]

Thanks for your help, I paid a couple bucks for a replacement Plunger, what a difference! Moves up and down freely, and good spark. Finally got it running, thanks again.

[engrtech]

I have an 820 snow throw with identical problem. I originally thought it was fuel, cleaned the carb, and then bought a new carb. It was very, very hard to start. It would run sometimes. It turned out to be spark. I installed on of the new mag type spark coils that does not use the points and condenser. Problem solved. My blower starts on the 2nd or 3rd pull every time.

[hrb_715]

Need a shaft with gear for 5 hp bobcat snowblower