i installed a used B&S Craftsman I/C 17.5hp OHV engine in a scotts lawn tractor. it has been barely used in the last 2 years, according to the guy i bought it from.
it seem to have trouble on hills, hauling, and mowing. when i flip the throttle all the way up from idle, it takes a second or two to get up to max rpms. my old Intel engine revved much quicker than this.
when i engage the blades, the rpms drop by a few hundred rpms, and the blades also take a while to get up to speed. while mowing, the rpms drop further when i go up a small incline. they drop even more if i mow in 5th gear (i usually use 4th).
even when just driving around, the engine does not seem to have alot of power. i could pull wheelies and lay rubber down the driveway with my old engine, but this one just seems to be lacking the power.
why does it do this? i thought the carb may have been gummed up so i swapped it with my old one (exactly the same) but there is no difference. i also gapped the spark plug to .030"
2007-07-25 14:20:26 · 5 answers · asked by Anonymous in Home & Garden ➔ Maintenance & Repairs
the spark plug was at .025".
im just wondering why this engine does not put out as much power as my old one.
2007-07-25 14:21:15 · update #1
I'd be willing to bet that one of your valve seats have popped out from over heating. Being that it was used, you don't know for sure how well the last owner took care of it. If the carb was dirty or they never cleaned the old grass out of it periodically, etc... the engine will over heat from not getting proper air flow, allowing the block to expand. That's how the seats pop out!
2007-07-28 07:14:02 · answer #1 · answered by ridingmower69 1 · 0⤊ 0⤋
You might check the valve clearance. It sounds like a governor issue to me. How does the engine rev if you open the throttle butterfly by hand? One other long shot would be to check the key in the flywheel to make sure it is not partially sheared. When you put the new engine in did you did it have the throttle mechanism on the side? You might try putting your old one on it. It could have the wrong spring in it. I just started mine and when you move the Governor lever the engine revs instantly. When you push the throttle lever up it revs a big slower but still very responsive. Try reving the engine with your finger and not the throttle lever.
2007-07-25 23:05:18 · answer #2 · answered by renpen 7 · 1⤊ 0⤋
I'm guessing that its bigger than the other engine, see if you can test the compression of the cylinders, also there may be too much or too little back pressure in the exhaust system. that and inspect the fuel system. anything and everything (lines, filter, etc.) that the fuel passes through obviously needs to be clean.
2007-07-25 22:29:44 · answer #3 · answered by Dwayne J 1 · 0⤊ 1⤋
Epic,
Have you checked the carburetor linkage yet? It sounds like it isn't working and stuck! Probably gummed up inside the carb from sitting for a couple of years.
Haven't steered you wrong so far. Check it and see if you can move it with your finger.
2007-07-25 21:30:02 · answer #4 · answered by Bart S 5 · 0⤊ 1⤋
try the fuel filter and replace the air filter. That might help you out some.
2007-07-25 22:31:11 · answer #5 · answered by johnny_g58 1 · 2⤊ 0⤋