Briggs Vanguard V-Twin Question

Kelly MT

Member
I have a B&S 18 HP Vanguard V-Twin on a chipper. It's new to me and runs but has a "crackle" kind if sound I can hear in the exhaust and from the carb. The exhaust muffler also gets red at the top. Ideas. adjustments? Thanks, PK.
 
I agree with El Toro. On older engines I've had to "re-drill" the carburetor main jets to run on today's gasahol. Before doing anything you might see if you can get hold of some ethanol free fuel to try first.
 
Here are the checks I've done. Compression is 145 and 150 PSI, the valves were very loose reset to .005". Is that the correct clearance? I drained the gas and put fresh gas in. It runs much better and the crackling noise is gone. But after a 10 minute run at speed it would idle good. I shut it down and after a few minutes did a restart, wasn't as smooth as before but still better. Is the loose flywheel a common thing? Also, no air cleaner. PK
 
Put a air cleaner on it. The air cleaner provides a slight choking effect and will richen it up some. I remember a ATV I had that would not even run without the air cleaner installed.
 
MAN I hate that. I started typing out a reply and the power went out. Power company is fixing the poles up the street. Will post that story over on the off topic post. Anyhow,,, you can have several problems that sound like this. That sound can be mini back fires in the muffler. the engine is not breathing correctly. These engines have several little things that will do this noise. First off pull the hood off and find the muffler. I have two Husqvarnas with these engines and they are not too hard to work on. Remove the two bolts that hold the muffler in the frame and take your little propane torch and heat around the pipes a little so you can GENTLY tap a little on the muffler and get it out of the tractor. If it is a newer machine you will see two "collars" inside of the muffler. What happens is the tack welds break and that collar falls into the muffler. this blocks off the exhaust. Thus that crackle sound. You need to take a pair of channel locks and lift that collar so they line up again. Drill four 1/8 holes through and use some #6 1/2 inch machine screws to hold everything back together. Some older mufflers do not have these collars.
One other thing I do is take a little grind stone and make an extra opening on the bottom side of the pipe. Aim it to the middle of the muffler cause this lets things breath better. You can see in the photo where the top edge of the muffler is on the pipe. If this doesn't fix your over heat problem you have a very slightly sheared key. When you pull the fly wheel and replace that $1.oo key you need to replace that convex washer or use a big honkin lock washer on top of it. The original gets weak and the wheel can turn ever so slightly. This will cause that over heat and fussy starting too.
Carb problems with these engine can go two different ways and first thing you need to do is tell us what carb you have. Take off the air filter and look to see if you have a single or dual throat carb. Get back to us after you do the first things and we can go into how to fix your carb. I have worked on and fixed I think eight of these engines now and everyone is happy now. They really work great when set up correctly.
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These Brigs engines have NIKI carbs and they cannot be set. That is why I put in my other reply for him to do the first two things and then we can get into the carbs. They are a balanced system carb and there is one or two little things that throw them off. If these carbs are all set up they work great. Let us see if he replys first.
 
On fleabay there is a guy selling a little kit to fix the Niki carbs. Normally you must replace the jets but this kit replaces just the little "O" rings that leak. Don't drill the jets on these carbs. Keep in touch and we will get her going. Look up 171989922920. Picture shows the tiny little jets.
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I'll have to order the air cleaner and several air cleaner assembly parts that are missing. I ran it for about 15 minutes today and it ran nice and smooth. Here are some pictures of the motor we are talking about. I'll post back when I get the parts. PK

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Well I finally got the air cleaner parts. After installing them the engine runs great. Thanks for all the help. PK
 

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