Hi,
I've been struggling with my Yanmar 1GM10 (single cylinder, 8 hp) engine
for quite a while now. Original symptom was that it just wouldn't run,
which most likely was caused by faulty injector. I say "most likely"
because I think I also managed to get water in the cylinder and now the
main reason for not running is total lack of compression. Outch, I hear
you say.
I've been trying to look for any cracks in the block or head, but there
are none. I know now cylinder wall has no cracks; if I take the head off
and place a plastic cover on top of the cylinder and crank the engine to
move the piston downwards, there most definately *is* compression as it
is very hard to crank.
With the head installed back in, I hear the air go in and out through
cooling water passages as I cranked the engine.
To find out how does it get there, I took the head back out, closed all
but one water passages in it and supplied compressed air into the
left-open passage. Turns out the air comes out from those small
precombustion chamber holes. So, there must be a leak from cooling water
passages to precombustion chamber.
I tried to take out the PC chamber, but stopped trying as I noticed I
started using more force than skill.
I have a PDF copy of the engine service manual, but I cannot see if
replacing the precombustion chamber would fix the problem, or if I need
to replace the complete head assembly
URL"728170-11700 1GM complete cylinder head assembly",
too.
Anybody had the same problem?
- Timo
--
Timo Heikkinen
Kaarina, Albin Vega #44
I've been struggling with my Yanmar 1GM10 (single cylinder, 8 hp) engine
for quite a while now. Original symptom was that it just wouldn't run,
which most likely was caused by faulty injector. I say "most likely"
because I think I also managed to get water in the cylinder and now the
main reason for not running is total lack of compression. Outch, I hear
you say.
I've been trying to look for any cracks in the block or head, but there
are none. I know now cylinder wall has no cracks; if I take the head off
and place a plastic cover on top of the cylinder and crank the engine to
move the piston downwards, there most definately *is* compression as it
is very hard to crank.
With the head installed back in, I hear the air go in and out through
cooling water passages as I cranked the engine.
To find out how does it get there, I took the head back out, closed all
but one water passages in it and supplied compressed air into the
left-open passage. Turns out the air comes out from those small
precombustion chamber holes. So, there must be a leak from cooling water
passages to precombustion chamber.
I tried to take out the PC chamber, but stopped trying as I noticed I
started using more force than skill.
I have a PDF copy of the engine service manual, but I cannot see if
replacing the precombustion chamber would fix the problem, or if I need
to replace the complete head assembly
URL"728170-11700 1GM complete cylinder head assembly",
too.
Anybody had the same problem?
- Timo
--
Timo Heikkinen
Kaarina, Albin Vega #44
Kaarina, Albin Vega #44 1966
www.timohei.net