- Nov 12, 2008
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- Real Name
- Randy Dockins
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I'm considering switching to a good synthetic oil for my 21 hp Briggs & Stratton engine. I have always used 30 wt. B & S brand oil in the engine and keep it changed about every 50 hours and new oil filter every 100 hours. My main purpose for thinking about going with synthetic is to hopefully reduce engine temps. From what I've read on the subject synthetic will let the engine run a little cooler and provide better lubrication. I am having some problems with the Boxxer 421 not wanting to run right after it gets hot and is either put into idle or shut down and restarted. It will back fire and run rough when trying to throttle up. Also, I can tell it's running rich on the fuel mixture. I'm going to try and adjust the carburetor and see if it helps with that. I had a compression test done at Jon Don and it was a low (40 psi I think). I was told there was nothing I could do to correct the problem which doesn't make any sense to me at all.
Can I switch from using regular oil to synthetic? Does anyone have any thoughts on why the engine runs rough and back fires when it's hot when you put it in idle and then throttle it back up? I'm seriously considering shelling out about 1500. for a new engine if I can't get this problem licked soon. I've already had the carburetor rebuilt and had the exhaust heat exhanger removed and cleaned. Every time I think I have this problem licked it rears it's ugly head again.
Can I switch from using regular oil to synthetic? Does anyone have any thoughts on why the engine runs rough and back fires when it's hot when you put it in idle and then throttle it back up? I'm seriously considering shelling out about 1500. for a new engine if I can't get this problem licked soon. I've already had the carburetor rebuilt and had the exhaust heat exhanger removed and cleaned. Every time I think I have this problem licked it rears it's ugly head again.