engine bogs down

[mancanic2 4]

to whom it matters,

 

I have a 91 520h 20 hp onan with a 60" deck. while mowing vacuum drops to 5"mg, engine bogs unless I move a a snails pace. high grass fresh doesn't matter. any help is greatly accepted.  Dale

[russellmc301 600]

check your spark plug it may have something to do with it.

 

the pros will be here to help in a bit

[boomers_influence 106]

dale

what is high grass fresh?

bogging could be lack of power,

due to lack of fuel, or one of the cylinders going south.

do a compression and leak down test.

thank you. boomer ( the used onan engine parts guy, also NOS and new )

[mancanic2 4]

high grass/ fresh cut grass

 

[skrusins 128]

Are you cutting one third or more? That means if your lawn is 3in  tall your suppose to cut only 1 in.

[mancanic2 4]

did not know that, but do have deck raised, and scalp wheels at highest posistion

 

[ericj 1,579]

a good running onan shouldn't bog down in 3" high grass. like said above check compression on both cylinders, sounds like it might be heading south, I just reread your post, with a 60" deck in real thick high grass it may bog some but should go through, maybe a video of it in action, good luck

 

 

 

 

eric j 

[mancanic2 4]

Grass was close to 6" or 7". Dry, Engine runs 12' of vac. until pto is engaged, vac drops uses alot of fuel but runs well. both spark plugs are white at gap, might be running lean? pics and vid tmrw

[skrusins 128]

Once you get cut down at a snails pace. You may have to cut more often, especially during early spring.

[mancanic2 4]

does this even on well mowed lawns, blades spin up after a moment.. kinda like heliocopter blades or the sound of them.. just lack of full engine power

 

[mancanic2 4]

problem solved. had drive belt way to tight and grass was just to high for speeds I was mowing at.. all insights taken thank you!