hi guys, just joined the forum. i'm in Australia and have what i believe is a gray market L1 22DT refurbished by SOTA tractors.
i was using it the other day when the engine suddenly began missing upon acceleration. i blows black smoke when trying to accelerate, misses then picks ups revs. lacks power.
i have checked the fuel system as far as supply to the injector pump which seems ok. with engine running there is fuel at each injector.
by chance i put my hand over the air intake and noticed pressure coming out like as if the compression stroke of one of the cylinders was pushing back into the intake. i took the air cleaner out and it was loud and clearly there was something pushing air out into the intake.
i thought perhaps that maybe there was a broken valve spring allowing this to happen, (which would explain the sudden onset of the issue) so i pulled the rocker cover to find that all the springs are fine.
thinking about it more, is it possible that the head gasket has blown in between cylinders allowing cross feed of compression between cylinders and into the intake? this would also explain the sudden onset of the issue.
if i take the head of to inspect it is it mandatory to use new head bolts and gasket even if the old one is intact?
i was thinking of testing this theory by taking the the rocker assembly off then applying compressed air to the cylinder via the injector port. i can then manually depress the intake valves to check if it is bypassing between cylinders. being careful not to cause valve/piston contact of course. but i guess i don't have to have the rocker assembly off to do this if i just crank the engine by hand to close the valves in each cylinder before testing.
can anyone give me the head bolt torque specs and sequence? also the rocker assembly torques and valve clearances?
am i on the right track or is there some thing else to check? the back pressure through the air intake was a huge red flag to me that's all.
thanks. clint
i was using it the other day when the engine suddenly began missing upon acceleration. i blows black smoke when trying to accelerate, misses then picks ups revs. lacks power.
i have checked the fuel system as far as supply to the injector pump which seems ok. with engine running there is fuel at each injector.
by chance i put my hand over the air intake and noticed pressure coming out like as if the compression stroke of one of the cylinders was pushing back into the intake. i took the air cleaner out and it was loud and clearly there was something pushing air out into the intake.
i thought perhaps that maybe there was a broken valve spring allowing this to happen, (which would explain the sudden onset of the issue) so i pulled the rocker cover to find that all the springs are fine.
thinking about it more, is it possible that the head gasket has blown in between cylinders allowing cross feed of compression between cylinders and into the intake? this would also explain the sudden onset of the issue.
if i take the head of to inspect it is it mandatory to use new head bolts and gasket even if the old one is intact?
i was thinking of testing this theory by taking the the rocker assembly off then applying compressed air to the cylinder via the injector port. i can then manually depress the intake valves to check if it is bypassing between cylinders. being careful not to cause valve/piston contact of course. but i guess i don't have to have the rocker assembly off to do this if i just crank the engine by hand to close the valves in each cylinder before testing.
can anyone give me the head bolt torque specs and sequence? also the rocker assembly torques and valve clearances?
am i on the right track or is there some thing else to check? the back pressure through the air intake was a huge red flag to me that's all.
thanks. clint