Forum for air cooled diesel engines and clones

[CallMeColt]

I still have a Yanmar L100 hooked to a 28 volt DC genset I would like to sell. Perfect for off grid battery backup. I believe you would use it in a 24 volt system.

Still have it?

 

[panamaguy]

Hi .love to see the videos if you get them posted as far as new members posting videos i am not sure as i am just new also .to me the big question is can i throttle it like a car throttle .and what is the low end idle speed

 

[CallMeColt]

Hi .love to see the videos if you get them posted as far as new members posting videos i am not sure as i am just new also .to me the big question is can i throttle it like a car throttle .and what is the low end idle speed

Yes, you can change the throttle. Yanmar has many different types of linkages to the governor for that delivers fuel. Some have a hand knob, some have a cable linkage, & the most common is the sold "run" lever to keep the throttle at 3600 RPM.

 

[CallMeColt]

Here are some videos from my last rehab project, an MEP-501A generator. Long & boring but some good information in there!

MEP 501A Rehab Part 1

MEP 501A Rehab Part 2

MEP 501A Rehab Part 3

MEP 501A Rehab Part 4 - Completed!

 

[CallMeColt]

Another project I did. PAD125A Diesel Pump. Has a Yanmar L40 in it.

PAD125A Pump Rehab Part 1

PAD125A Pump Rehab Part 2

 

[CallMeColt]

This project took me a LONG time to get going right... an MEP 831A generator. But, in the end, I got it all squared away!

MEP 831A - Initial startup & troubleshooting

MEP 831A - First repairs & load test

MEP 831A - More repairs & 3,673 watt load test

MEP 831A - 6 hour 100% load test

MEP 831A - Final repairs & project complete

MEP 831A - Part 1 Speed controller & governor adjustments

MEP 831A - Part 2 Speed controller & governor adjustments

MEP 831A - Fuel level gauge & sender replacement & improvements

MEP 831A - Fuel pump replacement

 

[CallMeColt]

I'm currently working on another unit... a Pramac S5500 generator with a Yanmar L100V in it. Worked out some of the electrical issues on it. Then, after finally completing the repairs on those, the engine stopped running right. Just barley sputters & never comes up to speed. After triple checking everything, I'm going to attempt to lap & clean up the valves. It's my last hope!

 

[CallMeColt]

I'm currently working on another unit... a Pramac S5500 generator with a Yanmar L100V in it. Worked out some of the electrical issues on it. Then, after finally completing the repairs on those, the engine stopped running right. Just barley sputters & never comes up to speed. After triple checking everything, I'm going to attempt to lap & clean up the valves. It's my last hope!

Lapping the valves & seats didn't do the trick.

Opened up the injector & cleaned it all out real well.

Removed the injection pump & cleaned it well.

Fuel it making it's way to the injector just fine.

Compression is good. I have no way of testing it, but, I can't pull past the compression stroke at all with the recoil starter.

I tried two other injection pumps with the same results.

Even though it ran perfect & all the sudden didn't, my best guess now is injection timing changing for some reason. Going to order a few different shims to try & go from there. The tools required to do the timing exactly are unobtainable when searching the part numbers in the manual from Yanmar.

 

[CallMeColt]

So, I was able to find the adapter for doing a compression test. ~420 psi. Well within the normal range as per the manual.

Went through the procedure to find the "real" TDC if by change the mark on the cooling fin was off. I came up with it being ~ 1/8 in sooner. Marked & adjusted the valve clearance again.

Still just barley runs & chugs along. Very lost here!

I have good fuel delivery, compression, & air. It HAS to be some sort of timing issue but it has me stumped.

Maybe it's time for the scrap bin.

 

[90cummins]

Lapping the valves & seats didn't do the trick.

Opened up the injector & cleaned it all out real well.

Removed the injection pump & cleaned it well.

Fuel it making it's way to the injector just fine.

Compression is good. I have no way of testing it, but, I can't pull past the compression stroke at all with the recoil starter.

I tried two other injection pumps with the same results.

Even though it ran perfect & all the sudden didn't, my best guess now is injection timing changing for some reason. Going to order a few different shims to try & go from there. The tools required to do the timing exactly are unobtainable when searching the part numbers in the manual from Yanmar.

I agree with injection timing, been there before.
Perfect injection timing is essential for a smooth running engine.
I have repaired 3 Yanmar air cooled diesels with the same issues.
Two L70 and one L100 clone.
The L70 had damaged camshafts from moisture which pitted the injection pump cam lobe.
The L100 clone had a bad needle bearing on the camshaft which in both instances effects the injection timing.
Remove the injection pump and cam follower and inspect the follower surface that contacts the camshaft.
Also look at the cam lobe as you slowly turn the engine. If there is pitting or spalling on the cam surface there is your problem.
Also remove the oil filter screen there should be no magnetic particles on it.
If so that is indicative of a failed cam bearing or lobe.
Photos of your findings (if any) will help.

90cummins