YANMAR 60 TURBO idles but dies at higher RPMS

[Alterboy 65]

Hello All, I have a friend off the coast of SC right now who has a yanmar 60 turbo .Idles fine but will not run at higher RPMs . He has checked the filters and Bled it twice . ANy ideas ?
THanks for any help
ALTERBOY

[Empty Pockets]

Checked filters, or changed? I'd check them again. And air filter if he has one.

[kmacdonald]

Exhaust manifold and risers are clogged. If they are over five or six years old, replace them or clean them if they are newer and look good after cleaning.

[donradcliffe]

Its most likely a fuel problem. I'd check for a blockage in the pickup tube.

[Dadrock33]

Originally Posted by donradcliffe

Its most likely a fuel problem. I'd check for a blockage in the pickup tube.

Agree with Don . . . if she's running well at idle, I'd be looking for issues requiring more fuel to be delivered and restrictions in that area (fuel pump, filters, clogged lines, wax buildup [not common anymore], etc.)

[P3sailor]

Sounds like fuel starvation, some good points suggested by the others.

[kmacdonald]

He ruled out the filters, or so he said.

[Howler]

I agree with the fuel starvation hypothesis. Had the same problem on a Yanmar 27 last year. Especially likely if it starts running normally at high RPMs, then loses RPMs and stalls after some minutes (was 20 for us). Gunky fuel starts to get picked up and eventually clogs the pickup tube in the tank. Need to purge tank, and check, clean or replace everything in line (pickup tube, separator, lift pump, secondary filter, injectors). It will run better than before because the problem has likely been slowly progressing for some time.

[thunderhoof]

I recently had a problem with my Volvo Penta where it had a limited top RPM and showed black smoke. It was caused by a blocked exhaust elbow and manifold. But it did not halt. You have the issue that the turbo is bolted to the manifold making it hard to inspect. How about a failed wastegate?

[01kiwijohn]

Just recently encountered one of these cases. The engine had not been run hard enough nor had the injectors been serviced, for some years.
To rectify it took quite bit of labor, but not much expense in the way of parts.
Found the turbo was not spinning because of all the carbon in the volute housing. Also, the exhaust elbow partially blocked and the inter-cooler dirty as hell. In this case, you may be able to salvage the turbo by just dismantling and cleaning it. (if doubtful of your own skills, get it professionally done, or rebuilt) Clean out the elbow and remove and cleane the inter-cooler core.
This fixed the actual problem but we had the injectors cleaned and re-set; runs like a top now.
If you're going to routinely charge the batteries, I suggest you do not just run the engine at idle. Run it at about 1500 -2000 RPM, enough to pump plenty of air through the engine.

[ken_isw]

Recently picked up a nice boat for a "song" with the same problem...turned out to be the propeller! Get it checked!

[a64pilot]

Usually if it’s a restricted exhaust, it won’t rev, but will blow smoke as it’s getting fuel but not enough air, it won’t die though, just won’t spool up.
Usually if it’s a fuel delivery problem it won’t smoke, but may die and often will initially run up, then rapidly lose RPM, and as I said may die or almost die.
Bad, or carbon blocked turbo will also of course usually smoke as we again are getting fuel, but not enough air

[Oceanride007]

Another possibility is some blockage on the air side, or turbo not spinning. You mat be able to see the compressor after taking air filter off, maybe give it a spin with something like a screw driver. Compressor should be shiny and very free.

[getyourbone]

Collapsed fuel line? Hose clamp not placed properly and cutting off portion of fuel supply?

[Gavray]

Suggest remove air filter completely so that you can see directly down the inlet. Then try it - either the problem will be solved which means that there is a problem with the filter.
If it shows same problem then you have eliminated one of the three possible sources of problems which are: fuel in, air in, exhaust out.
What maintenance was done in or around the motor in the previous 48 hours before the problem started?
Get back to us and let us know further...
Cheers GRImage already added