Yanmar TS155 diesel Problem with biodiesel waxy 'residue'

patclem · Jan 23, 2018

I wasn't sure where to go with this. I bought a generator driven by an antique Yanmar TS155 15hp diesel engine. It's kinda fun - has a hand crank and a big flywheel. I bought it not running, claim was the primer lever wasn't returning right. I figured it would be a fun learning experience to buy it and fix it. I also knew it had been sitting up, but diesels are pretty forgiving about that, and it was stored in his garage.

After I got home, I drained the tank and what was left was this waxy mess, kinda like beeswax or something. I opened the fuel filter, more waxy mess. I bounced it off a couple of friends to figure it out. Well, I finally determined it had SVO or "biodiesel" in it, and I guess it either polymerized, or the fats solidified. Carb cleaner seems to loosen it but not easily. Next time I touch it I'm going to try some heat, and either some real diesel or possibly hot cooking oil (I understand it can soak up fats and you can pour it out).

I also thought I'd point my kerosene torpedo heater straight at it and warm the whole thing. I don't know if it's gotten into the pump or whatnot, but I hope heating the whole engine will loosen it up enough to blow it out.

Anyone else experience this and have a proven solution?

Thanks in advance.

jbrumberg · Jan 23, 2018

Welcome to TBN-

I have no real personal experience, but when I researched biodiesel fuel when it became available years ago the two fuel conversion concerns among a few was how biodiesel fuel lifted all the existing tank crud and it had a higher than petro-diesel cloud point/gel point.

You may have two challenges for your fuel filters.

LouNY · Jan 23, 2018

May have been bio-diesel, some people were trying to run those on straight fryer waste oil. They needed to be started on diesel warmed up switched to fryer oil and switched back before being shut down.
Moderate heat should melt it out and reliquefy it.

chevy791979 · Jan 24, 2018

What color is the "wax" ? And what is the temp like where you are ?

patclem · Jan 24, 2018

I'm in Tennessee. It's been cold, but it wasn't that cold the day I was working on it. The wax was pink-ish. The fuel was pink-ish for that matter. Could be fryer oil and off road diesel blended. I'll pour the heat to the whole thing and see how it goes. Thanks again. I'll follow back up after I get at it again.

PS - I've been a long time lurker. Plenty of other problems solved without me asking.

California · Jan 24, 2018

I doubt you have problems more severe than just low quality biodiesel hardened into wax. Gentle heat should get it flowing.

Then flush it with real diesel!

chevy791979 · Jan 25, 2018

Kerosene can solve this in a pinch. But remember kerosene has low lubrication property. So if used usually add some 2 stroke oil. But kerosene won't gel like #2 or #1 will at low temps.