Adding more fuel for more power?

   / Adding more fuel for more power? #1  

etpm

Veteran Member
Joined
Jun 30, 2021
Messages
1,655
Location
Whidbey Island, WA
Tractor
yanmar ym2310
First of all let me impress on you all that I am NOT gonna change how much fuel my injectors deliver. I am not gonna fiddle with my engine. So, I have a YM2310 that runs well and only smokes, and then not very much, when I accelerate quickly. When at full throttle and under load it doesn't really smoke. But I read here now and then about folks turning a screw to get more power from their engines. It seems to me that my engine is running at about peak power for proper performance. If an engine starts to pump out smoke is the hp really increased much? And wouldn't all that unburned fuel that is now black smoke be bad for the engine? I'm just curious. My tractor is the only diesel engine I have ever used. It runs great and I love it. Ain't gonna mess with it.
Thanks,
Eric
 
   / Adding more fuel for more power? #2  
The black smoke is simply unburnt fuel with no air blowing out the exhaust..
Engines are not sent out from the factory to their max limit on hp..(fuel setting)
One can easily turn the fuel up 10% without harming the engine & notice an increase in hp..
BUT.. what’s 10% without knowing what the fuel delivery is NOW.??
It’s a crap shoot.. you can turn the screw 1 FULL TURN and drive it, keeping an eye on the exhaust..
No smoke, go another FULL TURN and repeat..
Once it starts to smoke, TURN THE SCREW BACK, 1/2 TURN..and repeat..

It sounds as if yours is at its hp limit.?? A black haze when rev’d and clears up when max rpm is achieved.
Just for kicks, try it without the air cleaner in and see if u get the same black smoke.
If no smoke, time to change the air filter..
 
   / Adding more fuel for more power? #3  
The black smoke is simply unburnt fuel with no air blowing out the exhaust..
Engines are not sent out from the factory to their max limit on hp..(fuel setting)
One can easily turn the fuel up 10% without harming the engine & notice an increase in hp..
BUT.. what’s 10% without knowing what the fuel delivery is NOW.??
It’s a crap shoot.. you can turn the screw 1 FULL TURN and drive it, keeping an eye on the exhaust..
No smoke, go another FULL TURN and repeat..
Once it starts to smoke, TURN THE SCREW BACK, 1/2 TURN..and repeat..

It sounds as if yours is at its hp limit.?? A black haze when rev’d and clears up when max rpm is achieved.
Just for kicks, try it without the air cleaner in and see if u get the same black smoke.
If no smoke, time to change the air filter..
Per the Yanmar parts manual, there is a section giving the tractor stats on things before the full figure break down. In there, it says the performance of the engine for my machine is 2600rpms. The tach at the time would reach about 2750rpms when I pulled on the throttle to max.

hen, I noticed the throttle linkage before the fuel pump has a threaded end and a nut. I did exactly what you mentioned. I turned the nut. Got to 2800rpms. Tuned the nut. Got to 3000rpms and left it.

My tach goes to 3200, so at 3000, the speed is 15kph in the highest powershift setting.

Eric, is this what you are aiming for?

DSCF4228.JPG
 
   / Adding more fuel for more power? #4  
Minor aside on turning engines up.

I have a diesel made by a different manufacturer. In the tune that I have, it is supposed to be good for about 9,000 hours before an in frame rebuild, and twice that for a full teardown. The Coast Guard uses the same engine with the injectors and turbo boost cranked up for high specific HP. The engines in that tune are rated for about four times the HP of my engine, but the Coast guard tuned engines are required to have a full teardown and rebuild at 600 hours...I could not believe a) how much HP they got, and b) how fast the engines got burned up.

The old Lister diesels ran forever because they weren't pushed.

And now back to our regular channel, and the entirely reasonable question asked by @etpm.

All the best,

Peter
 
   / Adding more fuel for more power? #5  
There is a big difference between RPM AND HP.!!
B.. all u did was increase RPM’s.. THAT will allow the HP to extend its range before the governor kicks in and slows it down..
IN THE manual does it specify, hi idle no-load speed.?? And hi idle full load speed.??
Usually they’ll list just hi idle speed..which usually means hi idle no load speed..
And there is a 10% difference between the two..
No load will be 10% higher than full load because of the work load being put on the engine..
If hi idle is listed at (example) 2000 rpm.. then hi idle full load will be 1800 rpm..

B.. u didn’t increase HP, u increased the RPM (length of time) that the HP stayed in that range..
I hope this makes sense..
 
   / Adding more fuel for more power? #6  
IN THE manual does it specify, hi idle no-load speed.?? And hi idle full load speed.??
Usually they’ll list just hi idle speed..which usually means hi idle no load speed..
The manual shows, the gov should kick-in at 2990rpms. :) One reason why I only tweaked it to 3,000rpms for the tach.

The power curve shows PS 26Hp @ 2600 rpms. It's nearly a 1.3L diesel.

1717448389178.png
 
   / Adding more fuel for more power? #7  
First of all let me impress on you all that I am NOT gonna change how much fuel my injectors deliver. I am not gonna fiddle with my engine. So, I have a YM2310 that runs well and only smokes, and then not very much, when I accelerate quickly. When at full throttle and under load it doesn't really smoke. But I read here now and then about folks turning a screw to get more power from their engines. It seems to me that my engine is running at about peak power for proper performance. If an engine starts to pump out smoke is the hp really increased much? And wouldn't all that unburned fuel that is now black smoke be bad for the engine? I'm just curious. My tractor is the only diesel engine I have ever used. It runs great and I love it. Ain't gonna mess with it.
Thanks,
Eric
Eric,
Your YM2310 specs.
1717453589433.png
 
 
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