Just completed an engine swap from a 12.5hp to a Briggs 16 hp Vanguard.Swap went fine but have not hooked up the charging circuit yet.The engine is model 303447 and has two red wires coming off it,1 to ignition and 1 from the rectifier/regulator.My question is why do I not get a voltage reading on the rectifier wire? Thanks for any help on this.Gord

Hi,
It is exceedingly rare for B&S to use red wires for the ignition and if you run battery voltage to the coils by accident, you will destroy them.
I will attached a Briggs document to help you identify your charging system components. I need to know what you have, or a type number.
There is a poster available, but it is rather cumbersome.
Peace,
Clarke
PS Hopefully someone will move this to Tools an Power Equipment Forum.

Hello Clarke-I looked at this wiring diagram before but here is what I have.Engine is a 16hp horizontal shaft Briggs OHV Vanguard engine with electric start.Two yellow wires come out from the alternator into the rectifier/regulator.One red wire exits the rectifier.A second red wire exits from under the flywheel housing(it does hhave a loose plastic sleeve on it(black)but it is not part of the wire-most likely to give some protection from chafing etc.. The model of my engine is 303447,type 1269-E1-4420,98063011.So from what I can gather the engine is a 16am regulated system with DC only coming from the regulator-it shows an alternator inline on the regulator/rectifier line on one wiring diagram but I have not hooked up anything to this until I am sure.Tks Gord

Crigby-forgot to mention this motor although 1998 vintage I believe is unused-bought new by me and never used until now so no reason to suspect a bad part(yet anyway).The motor runs perfectly but without the charging circuit hooked up as yet.Tks Gord

Hi,
It would depend on the size of the magnets under the flywheel as to what amperage it is; it si the 10-16 amp system.
I would first check the output of the alternator for about 28 V AC. Then I would plug it back up to the regulator if it passes, and check for about 14.5 V DC. If you have one but not the other then start by looking for proper grounding of the engine. If ground is present then suspect the regulator.
Your engine was made Juno 30, 1998. Is it new and just sitting in a warehouse? Yours is a Japanese engine that was made completely by a single individual.
I will attach the poster; it is good though it requires scrolling in both directions.
Peace,
Clarke
PS There is the posibility that it requires battery voltage to use as a reference for regulation, also. Rare but it does happen in which case you would proceed with the AC test, hook it up, test battery without it running and then with it running. Should give the DC results already mentioned.

A coupla days ago I did the AC voltage test on the alternator and it was between 30-40 on spec.Nothing from the regulator on DC.I was told that it might need battery voltage to work but was leery to power the regulator with 12 volt in case of doing damage-I like to know before hand that all is correct.The engine was bought new by me and stored in my shop all this time-changed my mind on the project.Maybe it would be wise to fuse the regulator output line before hooking twelve volt up.As I see it the regulator was no good from new which is unlikely or it needs the 12volt hookup to get the DC reading.Tks Gord

Hi,
Putting a fuse in the circuit is always a safe thing to do. The battery voltage only serves as a reference for the system. It will put out the AC component without ground, but the DC component must have a viable ground to complete the circuit( only one red wire on the output, so the roundtrip has to be completed somewhere.)
Peace,
Clarke

Clarke working on my model A coupe today but tomorrow will give the fuse and wire hookup a try.I hhave a spare alternator around so I will put it inline to see if any charging or discharging going on.Pretty hard to test the regulator once I hook it up as the battery will feed 12 volt on the line the way I see it.Thanks for you ideas and I will let you know what I find out.Gord

Hi,
No you should test the battery statically before cranking; nominal would be about 12.6V, but I have seen as high s 13.4V. Then when you crank the machine the battery will have been partially discharged in the process and it could register as high as 16V and settle back to about 14V in short order.
Peace,
Clarke

What kind of oil for briggs & stratton vanguard 16 hp

Hi Guys..
I have a briggs & stratton V-Twin Vangard Model 303447
Ok problem: I put my test light on the spark wire & Ground it out on the engine, it looks like a great spark.. However when I put the spark plug in & ground it out on the engine I get NO spark..
Also I get a better spark when I disconnect the Stop switch terminal from the key switch..
Maybe a week spark? Maybe need 2 new coils? Please let me know what you think... Thanks!

Hi,
I would say you have described a bad key switch for one. Plugs do not come from the factory gapped correctly; 0.030" is correct but they usually come at one and a half times that. Also, try disconnecting the engine from the frame; should be a wire going to a threaded post in a nylon block somewhere just below the blower housing that will be the frame ignition ground. Unplug it and the engine is separate and you can see if the problem is with the engine or the wiring harness in the frame. Switch will not cut it off, but this is how you troubleshoot the problem to find out where it actually is.
Peace,
Clarke