There used to be a common problem reported with certain model Craftsman tractors that involved the rear brakes binding up and not releasing. Just one thing you might check. Also might be a drive belt problem or sheave? I'm sure others will chime in with good/better ideas....

I'd suspect a blown head gasket.
Disconnect one spark plug wire and ground it.
Take it for a test mow.
If it behaves the same, try the opposite side.
Compare results.

It seems to be engine related rather than something with the brakes. But thanks for the suggestion.

There's no smoke so I didn't think it was a headgasket. But I don't know for sure. Spoke with the shop I purchased it from (who is very busy right now) he said try changing the spake plugs again before he comes to pick it up. I did change them before using the machine this year and maybe one new one was bad.

You can still isolate it to one cylinder or not.

You would be wise to take Bill's advice.

Walt Conner

Thanks Bill and Walt.

Walt it's been a few years since you sent me directions on how to change the head gasket on a Husqvarna/B&S tractor I had. Job was easier than I expected and engine ran great for the 2 addition years I owned it. So Thanks again.

I'm a little confused about the current problem. Theres no smoke so does that indicate the head gasket is OK? Are Vanguard engines prone to head gasket problems with such low hours? I have 205 hours on the engine.

I'm going to wait till tomorrow and change both spark plugs. Hopefully that will solve the problem. Hopefully.

But Bill I'm confused. If I disconnect the spark plug wire (one at a time) and ground it and mow what could it tell me? I'm guessing if it runs the same that is badly on one side and dies on the other it means thats the side with the problem. Does that prove it's an ignition problem? Or could it also be a fuel problem on that side? Like I said I'm confused. I actually like working on small engines unfortunately I don't do it much and I learn as I go.

Thanks again guys.

Jim

Head gasket problems on vanguards is not common- but the head gasket ideas may apply.

here is another idea.

check the sparkplugs to see if they are black with carbon or soot. This would indicate an excessively rich fuel mixture.

During high speed with a load, the fuel may be passing through the high speed circuit on the carburetor. If the high speed air bleed is blocked, an excessive amount of fuel will be drawn into the engine. If you stop the tractor, the load is reduced, and fuel may be drawn through the idle circuit - and the engine recovers.

Many twins will actually mow (not well) on one cylinder.

It's a 23 HP engine. 23/2= 11.5 HP,

Problem solved. It was a clog(s) in the carburetor. I didn't clean the carb I had the local shop take care of it.

I will adjust valves, change head gaskets change transaxel fluids etc but don't do carburetors. Would like to but just don't know how to clean or adjust them properly. I did look on-line vids of how to clean a carburetor but didn't find anything that really helped.

Thanks to everyone who took the time to respond.
Jim

I have one on my sawmill , ran great until today halfway thru a cut it sputterd & wanted to die . I checked the fuel filter, just a few drops of water . restarted it & boom alot of smoke & it died , spark plugs both wet with fuel,oil, and fuel is in the crankcase oil , the tube from the breather to the valve cover is wet with fuel , could it be a carb float stuck open ? OR the head gasket ?