Preferred Oil for PV Cylinders

[bushwesl]

I almost feel embarrassed asking this question, since oil preference is so highly debated/discussed, but I haven’t seen anything that directly addresses preferred oils for PV cylinders.

Historically, I’ve used Maxima 927 at 32:1 with 110 in non-PV cylinders. I’m a 927 believer and it will continue to be my preference.

However, I will soon be running an ESR E2 cylinder with PV. I’ve read that castor based oils can gum up the PV, so a synthetic can be preferred to avoid this issue.

For those running PV cylinders, what oils have you found to be successful? Or do you still run castor based oil and deal with the gumming by maintaining/cleaning the PV at some frequency?

I’ve been looking at Maxima K2 & Klotz R-50. I know LED recommends Dumonde Tech, but it’s not easy to get near me. 

[broken1]

It was explained to me that the lubricants people generally use is based less on whats better than the other & based more on whats available & what the reps are pushing onto the bike shops in your area. There's alot of good products out there. Guys in my area ran Dumonde Tech until there was no more reps slinging it around here. I used to run Dumonde Tech trans fluid until the place I got it from stopped carrying it. I ran Torco GP-7 for over 20 years & have never had any issues but I recently switched to Klotz R-50. I'm a firm believer in synthetic pre-mix.

[atvmxr]

I've been running MC-1 for almost 30 years.  its says its for air cooled no-pv, it is full synthetic though.  for some reason, the last year its become unavaialble so be interested to see what people suggest for you. 

[The norm]

My engine builder recommends klotz R50. I don't have a pv R cylinder but it do have a CR250 with a pv and it gets full synthetic pre-mix. I ran yamalube in it for 10 years because the guy I bought it from used yamalube. When I get it back together I will run R50 for sure at 40:1 like I do in all my 2strokes

Loren

[havinnoj]

I ran R-50 on my motors for probably close to 10 years.  One of those was a PRO-X PV cylinder.  It did have some junk coming out of the tube - and that combined with the overall fact that the flashpoint of R-50 is 550*F and meant for riders who are really in the powerband almost ALL the time, I scaled back to Klotz Super Techniplate which is like 150*F (or more) lower flashpoint.  That was better for the riding style I have where I'm on the throttle and then a lot of cruising around - much less junk around.  This might not apply to you, but if so, here's a good chart for common premixes:
https://www.thumpertalk.com/forums/topic/1236332-2-stroke-pre-mix-oils-specs/

[atvmxr]

woah, thats alot of interesting info.  I havent read through it all, do they discuss how the mix ratio would affect the overall fuel-oil mix flashpoint?  LIke MC-1 at 50:1 with the 208F vs 927 at 32:1 and 420F. 
Also, i always figured the honda and yamaha oil were relabled belray or something else, but based upon their flash temps I guess maybe that is not true
 

[bushwesl]

That’s a great thread and spreadsheet! Thank you for sharing.

Here’s the direct link to the Google doc: https://docs.google.com/spreadsheets/d/1Akn5VQxEyzpdTNCafTL0YGI4SS02dQICtkxgwrWcBEE/edit?usp=sharing

do they discuss how the mix ratio would affect the overall fuel-oil mix flashpoint?  LIke MC-1 at 50:1 with the 208F vs 927 at 32:1 and 420F.

No, I don’t think they get into the mix ratios and the impact to fuel-oil mix flashpoint, unfortunately.

[atvmxr]

So, in theory, if my oil had a higher flash point it would had kept the rod bearing from overheating and spitting out a couple of needles?

[bushwesl]

So, in theory, if my oil had a higher flash point it would had kept the rod bearing from overheating and spitting out a couple of needles?

Oh no!

[The norm]

That poor piston!

[bushwesl]

As a follow up, I ended up going with Klotz R-50 based on the recommendations I’ve received and that it’s a full-synthetic, formulated for PV engines. My only hesitation was the high flash point, but since it will primarily be used in a racing application, I don’t foresee that being an issue, but more likely a benefit. Oh, and it has a “racy scent”😆 Thanks, everyone!

[The norm]

Excellent choice Wes. In reality with today's oil technology it would be difficult to find a "bad" oil. I think oils can be chosen based on riding type, terrain, and riding style. I use R50 and ride a combination of slow and fast. In the dunes my R sees long wfo pulls and slow cruising.
Loren