Forum for air cooled diesel engines and clones

[California]

There have been occasional posts about the same thing on the tractors - and the same remedy.

Long ago one dealer posted that he painted the muffler silver on his used imports. If the customer later complained about smoking, he always found that paint looking like new and advised the owner to work it harder.

 

[90cummins]

View attachment 4-15-14 Yanmar versus Generac calculations.pdf


I've recently performed fuel consumption testing on 3 of my portable generators.
Two Generac XL4000 and One Yanmar Diesel.
I have never seen a direct comparison between any generator and decided it was time that someone did one.
I was quite pleased with the results particularly because the two Generac XL4000 generators I tested that showed near identical results confirming my testing methods were consistent.
The smaller 6.7 HP Yanmar easily outperformed the 7.8 HP Generac's.

Review the data. I find it to be quite interesting. If you see any errors or have any questions/advice/ideas for a new test let me know!
The legends on the left are the units used for calculations.

In the future I plan on testing my turbocharged Ford 1720 with my 25KW Generac PTO generator.
The primary reason for this testing is to determine how long my fuel supply will last in the event of a power outage.
The data in blue at bottom illustrates fuel consumption vs. cost @ various loads.

Enjoy!

90cummins

 

[arjan]

Hello from netherlands, europe.

I have here a 74' john deere 110 that i have repowered with a yanmar L100 diesel (not a clone, its a real yanmar)
With the tractor a few weeks ago i roll in to a ditch with water.... the engine gets some water from the air cleaner and stops direct.
I cleaned up everything, remove the water from above the piston and refresh the oil.
So far.. the engine didnt start. Check compression: low compression so i opened up the engine te get new piston rings and a new piston.
I also get a new injector and fuel pump (one with a relay) Bolt everything back to the tractor and the engine starts and runs fine.
I start mowing a few minutes later, do a 200 meters or so and the engine starts smoking!
At first i think its the heavvy grass, so i stop and lift the mower, that didnt help.
take of the mower deck, didnt help.
The engine sounds looks like he works hard and smokes.
So i turn it of and try to start again, it wouldnt start.
After 15 minuter i try again and it starts, after 5 minutes running at 2800 rpm the engine starts again smoking and the engine speed slows down and stops.
Whats up here ?
(are the bearings worn or so ?)

 

[NateMonkey]

Sounds like you may have a bent rod or some other terrible thing going on inside that engine.
If it was running and inhaled a bunch of water, it could have damaged all sorts of things with the flywheel mass being stopped almost instantly.

You really should open it up and look it over. There may be something very wrong in there.

 

[DBakerPE]

I have a 1998 Gillette 5.5 kW generator driven by a Yanmar L100 air cooled diesel engine. It has about 280 hours on it in standby emergency use. No serious issues yet other than an oil leak on the oil pressure switch and oil/filter replacements. Last week when I tried to start it for a test run it stumbled for about 15 seconds and quit. Checking the fuel circuit I found a free flow to the fuel pump but nothing coming out, even with the high pressure discharge line disconnected. The local diesel parts supplier wants $400 in advance to special order the Yanmar pump. I found the Chinese knockoff version on Amazon for about $60, but it also takes over a month to arrive. That is on order. Does anyone have recent experience or caveats about using the Chinese injection pump?

I dismantled the old pump per the parts diagram I found in the manual others have pointed to on this list, but do not see any obvious problems. Does anyone know if these symptoms are consistent with a pump that can be overhauled successfully?

 

[DBakerPE]

I have a 1998 Gillette 5.5 kW generator driven by a Yanmar L100 air cooled diesel engine. It has about 280 hours on it in standby emergency use. No serious issues yet other than an oil leak on the oil pressure switch and oil/filter replacements. Last week when I tried to start it for a test run it stumbled for about 15 seconds and quit. Checking the fuel circuit I found a free flow to the fuel pump but nothing coming out, even with the high pressure discharge line disconnected. The local diesel parts supplier wants $400 in advance to special order the Yanmar pump. I found the Chinese knockoff version on Amazon for about $60, but it also takes over a month to arrive. That is on order. Does anyone have recent experience or caveats about using the Chinese injection pump?

I dismantled the old pump per the parts diagram I found in the manual others have pointed to on this list, but do not see any obvious problems. Does anyone know if these symptoms are consistent with a pump that can be overhauled successfully?

 

[90cummins]

The fact that it started & stumbled sounds like a fuel delivery issue.
Is there fuel in it, did you turn the fuel on?
Was the fuel filter recently replaced if so dirt could have entered during the replacement?
If you ran it out if fuel you need to bleed the system by loosening the line at the injector, putting the throttle on full and crank the engine until you see fuel with no bubbles coming out.
Does it have an electric solenoid on the pump? If so that could have failed.
If you loosen the injection line at the injector while cranking the engine over do you see any fuel squirting from around the nut?
There will be very little flow coming out of the injector line but there should be some.
If there is fuel squirting from around the nut but it still won’t run remove the injector and then attach it to the line and see if it's actually squirting fuel as a fine mist. Do not place your hand in the spray it will penetrate the skin.
If there is no spray the pump is bad.

The injection pump components are very precise so handle with care.
There should not be any scuffs on the plunger; it should look perfectly smooth with no exceptions. If this is not the case contamination entered the system and damaged it.

If it does spray pull the valve cover to see if the pushrods are in place.
E-bay has injection pumps for approx. $80

 

[Ilikeurtractor]

I just acquired two Yanmar L40 engines (not clones) and they run identically to the Launtop L100 I have on a snowblower - miss at around 3200 rpm or higher with backfiring sometimes and blowing white/gray smoke. I made sure the oil level was no higher than the "max" mark on the dipstick in case that was a cause. I can only conclude it is due to the relatively high elevation I live at. Apparently not enough air can get into the cylinder at these relatively high speeds and therefore not enough heat is building to ignite the fuel. I'll have a definitive answer this summer when I take a couple of the engines to a lower elevation and run them. I'll report my findings when I have them. I can't think of anything else that would cause this since all three engines act exactly the same way. Unless there is something wrong with my fuel source here (?)

Yup, it's definitely related to air pressure. All three engines, the Launtop and two Yanmars run good at 900 ft. of elevation. No missing at full 3600 rpm. I guess 3200 rpm = 6300' or about 11.7 psia of air pressure. Not sure if it's a direct relationship between pressure and max speed though. So if you're having this problem and you'd like to fix it, either turbo (if you can) or move to a lower elevation

 

[PILOON]

This is not limited to diesel engines, try running a chainsaw that was professionally tuned up by a shop at sea level and that same day using it at 2000ft elevation!
Better have a small screw driver in your pocket!
Or as I discovered with my VW beetle back in the 60's when I toured Mexico in the high mountains. At 6000 ft I could barely do 20 MPH and that was in 2nd gear flat out throttle
Changing the fuel jet cured that.

 

[buickanddeere]

As previously stated. Lightly loaded air cooled diesels are even worse for wet stacking than liquid cooled diesels.
Insufient flow on the low pressure side into the injection pump element could be suspect.
Could also be that the engine is just crudded and stuck with gum, goo and ash from being "lady driven".