Anyone know what this is??

[Captnem]

Black substance. I took the cylinder off my ski and noticed a ton of this stuff built up. I use castor 927 oil if that matters. Thoughts? Thanks!

[Myself]

That's sludgy gummy build up from the bean oil......it's a great racing oil that REQUIRES frequent engine teardowns. DO NOT use bean oil in a rec 2 stroke of any kind, good way to ruin an engine.

[Captnem]

Thanks! Geez I thought I was buying the “good stuff”. Had no idea it would cause build up like this.

[Myself]

"the good stuff" is something like Amsoil , royal purple, redline.... , really anything full synthetic.

[550headache]

I run the klotz bean oil and have never seen anything like that! Look like brand new when i blow the up(or used to till i switched to Yamaha motors). Never used anything else except klotz snowmobile tecneplate injection oil but my go to is the beanoil. Just my $.02


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[Myself]

Never used anything else except klotz snowmobile tecneplate injection oil

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.............which is synthetic, NOT bean oil. Klotz DOES still have "benol" which in fact IS still castor bean oil.

[Carter.104]

I run 927 in my mod 550 and never seen anything like this… definitely some kinda carbon build up but not sure if it’s specifically from bean oil. I could be wrong so talk to a reputable motor guy like Tim Tynan or zig and ask for their opinion

[WFO Speedracer]

Castor oil is for racing , a lot of freestyle guys use it but it's mostly guys with big stroker motors and they are doing frequent teardowns because they have no other choice.

Castor does not stay mixed with gasoline for long periods of time so you can't use left over fuel from last weekend, this works fine when you are using oxygenated fuels like VP race gas that has to mixed and ran, it loses octane from the second you pour it out of the metal can.

For rec use I would run something else.

[fox river pwc]

I've talked to guys that actually mix castor bean oil along with synthetic oil. The idea is that the synthetic keeps the residue from the bean oil from sticking and building up, but I've never tried this myself. I did run bean oil for a short time many years ago in my vintage race SJ and actually got a couple big globs of sludgy snot out of the exhaust shortly after...then went back to Klotz Skicraft.

[pro785]

I was using the Klotz bean oil in one of my pros. It's not pure bean oil anymore, just a small amount, like 10% or something. It overheated because the intake screen in the pump got clogged just enough to get it hot enough to do some damage. Considering how hot it got it did very little damage, but there was that black goo stuff in the wrist pin bearing and it pitted the connecting rod, but cylinder walls and stuff looked pretty good. I think that bean oil is meant for preventing major damage, but it's going to cause minor damage under regular operation. Only their racing oil has the beans, I use Klotz in everything else and never really have major problems.