1gm10 issues

[PaulMcK]

I bought an unloved sadler25 a few years back. It's yanmar 1gm10 was out. Have been at trying to get it going. No experience with deisel engines, it's been a steep learning curve that's led to an impass.

I'll run through problems so far.
stuck tappets. solved
very low compression. head off pitted valve seats. got hold of a seized scrap 1gm10. decent head on it NB;old head had half the pre-combustion chamber missing. put new valves in. lapped them in(pretty well I think) still low compression
pulled piston out found stuck rings. bit the bullet put a new piston in after honing cylinder(was a bit glazed) good compression, nearly imposible to hand crank.
took apart injector cleaned it.
wasn't cranking fast enough for me so new starter motor.
new oil, oil filter, fuel filter, v-belt, impeller and water pump seals (was dripping a bit)
bought a new battery(more cranking power than dead one in the boat)had a go at starting her and no go
injector is spitting a decent spray(had it connect to fuel line out of head)
if I squirt easy start in the intake she'll fire till squirt runs out other than that she'll only blow pretty smoke rings
can the injector pump be weak and need a clean/service?
does there return bango bolt on injector need some back pressure?
I'm at a loss as to whats wrong and am somewhat invested in it.

really don't wanna miss another season.
hope someone on here can help

 

[gordmac]

Injection timing?

 

[RobF]

When you're making comments about low compression vs good compression, are you testing it with a compression tester or just from turning it over by hand? And if you open the decompression lever, does the engine spin reasonably easy by hand?

If the engine is turning over quickly on the starter and not starting, it can only be one (or more) of 5 issues...
a) Lack of compression
b) Lack of fuel
c) Fuel is being delivered at the wrong time
d) Lack of air
e) Inability of exhaust gases to exit

Just need to work through each one methodically

 

[pandos]

It may sound sily but have you checked the stop cable/lever on the pump?

Otherwise my money is on timing being out fuel being delivered into the exhaust stroke...or something like that..

 

[PaulMcK]

It may sound sily but have you checked the stop cable/lever on the pump?

Otherwise my money is on timing being out fuel being delivered into the exhaust stroke...or something like that..

have twiddled the kill level. if this was problem I thought fuel wouldn't get through to injector and it is. there is a bolt with a lock nut on the casing with a anti tamper wire through it. is this for adjusting timing. also there's a timing shim between injector pump and housing mentioned in the service manual.
if i get a chance over w/end I'll take rocker cover of and hand crank to see if injector fires just before top of compression (correct time as I understand it)

thankfully for any help/advice you can offer

 

[PaulMcK]

When you're making comments about low compression vs good compression, are you testing it with a compression tester or just from turning it over by hand? And if you open the decompression lever, does the engine spin reasonably easy by hand?

If the engine is turning over quickly on the starter and not starting, it can only be one (or more) of 5 issues...
a) Lack of compression
b) Lack of fuel
c) Fuel is being delivered at the wrong time
d) Lack of air
e) Inability of exhaust gases to exit

Just need to work through each one methodically

don't have compression tester. with decompression lever pulled she hand cranks easily. without she'll break your arm. I don't know if some eejit has been messing with timing. someone had removed half of pre-combustion chamber so it's possible. need to study up on setting timing me thinks

thanks for your advice

 

[bristoljim]

The compression you have should be good enough -if you have not dismantled the injector pump the timing should be ok -you have had the injector apart so take it to a fuel shop to check general health & spray pattern.Give the stop lever & throttle lever plenty of exercise & penetrating oil to make sure its going to full fuel position - then try again
Jim

 

[andsarkit]

My 1GM starts instantly in the summer with the throttle on tickover but can be quite reluctant in cold weather as it has no heaters. I think there may be an optimal throttle for cold starting and maybe use the decompression lever to get it moving first.
You could try a hot air gun into the air intake (remove the foam filter first) to see if that helps.

 

[Solostoke]

Whereabouts are you? I'm happy to look at it if you're nearby. I'm sure there are others who would offer the same.

 

[Wing Mark]

It runs on easystart, so the valves must be doing roughly the right thing?

Which suggests checking:
a) is it actually injecting fuel?
b) is it injecting fuel at the right time?

I don't know how you check timing of injection, but there must be a way of setting it up?

 

[RMC]

When I removed the head from my GM10, the dealer warned not to score the pre combustion chamber when pressing in the washers/heat shields or it will not start. He pressed in the parts for me and all was good

 

[IanCC]

There is a very good yanmar owners group on Facebook. Lots of knowledge there.

 

[PaulMcK]

It runs on easystart, so the valves must be doing roughly the right thing?

Which suggests checking:
a) is it actually injecting fuel?
b) is it injecting fuel at the right time?

I don't know how you check timing of injection, but there must be a way of setting it up

When I removed the head from my GM10, the dealer warned not to score the pre combustion chamber when pressing in the washers/heat shields or it will not start. He pressed in the parts for me and all was good

Whereabouts are you? I'm happy to look at it if you're nearby. I'm sure there are others who would offer the same.

not likely close. Co. Down in Northern Ireland

 

[PaulMcK]

When I removed the head from my GM10, the dealer warned not to score the pre combustion chamber when pressing in the washers/heat shields or it will not start. He pressed in the parts for me and all was good

didn't remove chamber from that head. injector was seized in it and was a nightmare to remove. the top copper washer did look a bit tired. didn't see the shield below. I did buy an outer chamber section for the original head. when you say score it do you mean the internal sphere of the chamber or the side wall. as I recall it didn't need pressed in, was snug but just slid in

 

[RMC]

didn't remove chamber from that head. injector was seized in it and was a nightmare to remove. the top copper washer did look a bit tired. didn't see the shield below. I did buy an outer chamber section for the original head. when you say score it do you mean the internal sphere of the chamber or the side wall. as I recall it didn't need pressed in, was snug but just slid in

It's quite a long time ago but I think it's the actual spherical pre combustion chamber that should not be scored. I did have to remove the injector as I had combustion gases leaking past the sealing copper washer. There should be a heat shield below the washer from memory.

 

[Bilgediver]

I bought an unloved sadler25 a few years back. It's yanmar 1gm10 was out. Have been at trying to get it going. No experience with deisel engines, it's been a steep learning curve that's led to an impass.

took apart injector cleaned it.

Now what exactly did you do here? Do you have the equipment to clean and reset an injector and did you check the spray pattern.

Maybe you did something wrong and the injector is no longer spraying correctly. Normally Injectors are taken to injection specialists who have the expertise and knowledge to clean, reseat, test and calibrate.

You may be able to connect your injector to the fuel pump without inserting it into the head. You can then test it by cranking the engine and looking at the spray pattern It should give a good pattern and no drips.

Keep your eyes and skin well away from the spray as it has the force to penetrate your skin. If the injector is hosing and not spraying correctly then take it to a specialist near by. Google will help you find one. You may need a new nozzle which is not expensive.

 

[B58]

I bought an unloved sadler25 a few years back. It's yanmar 1gm10 was out. Have been at trying to get it going. No experience with deisel engines, it's been a steep learning curve that's led to an impass.

I'll run through problems so far.
stuck tappets. solved
very low compression. head off pitted valve seats. got hold of a seized scrap 1gm10. decent head on it NB;old head had half the pre-combustion chamber missing. put new valves in. lapped them in(pretty well I think) still low compression
pulled piston out found stuck rings. bit the bullet put a new piston in after honing cylinder(was a bit glazed) good compression, nearly imposible to hand crank.
took apart injector cleaned it.
wasn't cranking fast enough for me so new starter motor.
new oil, oil filter, fuel filter, v-belt, impeller and water pump seals (was dripping a bit)
bought a new battery(more cranking power than dead one in the boat)had a go at starting her and no go
injector is spitting a decent spray(had it connect to fuel line out of head)
if I squirt easy start in the intake she'll fire till squirt runs out other than that she'll only blow pretty smoke rings
can the injector pump be weak and need a clean/service?
does there return bango bolt on injector need some back pressure?
I'm at a loss as to whats wrong and am somewhat invested in it.

really don't wanna miss another season.
hope someone on here can help

I would check the start spring which is mounted inside the front cover, the spring sits on the governor shaft between two mounting posts. what happens the spring holds the fuel rack longer in excess fuel position allowing the engine to cold start. The spring weakens over time and the rack to come out the excess fuel quicker. take off the oil filling plug off the front cover and you can see the pump and the rack , when cranking your engine over you will see the fuel rack move the governor is pulling it back, see if it shoots back? that will confim there is an issue.

Just another thought , did you check piston protrudence above the block without the gasket it should mesure approx 0.07"thou? if its flush with the block the con-rod is bent?

 

[Chacho2]

better to check the workshop manual :

Engine Manuals Yanmar