Fuel : Oil Mix...........?

[johnnyboxer]

Some debate on another thread.

BVM said to run mine in on Castrol TTS @ 50:1

then change to 66:1 to run from then on................but never run the bike......... as the Montesa manual states with Elf @ 80:1 (too lean).

However the Castrol TTS bottle says to mix @ 50:1 only

Confused.......??

Think I'm going to run Castrol TTS @ 50:1 all the time................

Anybody shed some reliable light on the said subject............for the 315?

TIA

JB

Edited March 20, 2004 by Johnnyboxer

[monty-python]

I run mine now at 50:1 with ipone oil and have no problems.

I have in the past run at up to 80:1, and it seemed ok.

The montesa manual (for the 03) recommends 50:1

As they say "oil is cheap, engine rebuilds aren't"

BTW don't run it on unleaded, it will knock (unless you add octane booster)

Shell optimax works ok, as does 4 star, if you can get it

Edited March 20, 2004 by monty-python

[wonder boy]

i run my bike a 80:1 are it revs out btter than 50:1. I recomed 80:1 i seems to be a lot better at reving out cleaner than 50:1.

Gavin

I got told by a mechinc at the SSDT (montesa one) to run my bike at 80:1.

[munch]

i done scotland and 4 day french trial over 600km in 90deg heat 80:1 ipone

no trouble using unleaded and no knocking thats probably a couple of years trialling mileage for some

[mark christopher]

80:1

Edited March 21, 2004 by mark christopher

[munch]

i agree with mark

[subira]

I seem to remember that JB's bike is new.

Run a couple of tanks through of non-synthetic oil @ 50:1, then once you've run it in go to 80:1 synthetic.

Don't ask me why, but this is what all the race engine builders recommend, and I seem to remember the lads at BVM saying the same.

TTS is synthetic.

Me I run 80:1 Ipone and use it regularly in road trials and like everyone else have no problems.

[dgshannon]

The only issue I have ever heard regarding the break in period and non-synthetic oils has to do with the bottom end. It has been argued that using regular oil is necessary for all the bearings to actually have enough friction to break in properly. Interesting theory. I can't imagine that using a non-synthetic premix during break in would matter though.

As far as the mix ratio, I use 80:1 synthetic in modern engines. I have done this in a 97 Beta, 99 & 00 Montesa, 02, 03, & 04 Scorpa. The 3 Scorpas had 80:1 even during break in using Motul. I use 50:1 synthetic in my vintage 1974 Cota 247 without problem. Personally, I think 50:1 in a modern engine is way too much oil.

Edited March 22, 2004 by DGShannon

[subira]

DG what ever the theory the engine builders seem to believe in it, 2 stroke or 4 stroke. They seem to believe that the synthetic is too slippery !

My mate just picked up his CBR600RR motors for this years 600 Supersport series, the builder was really specific about the use of non-synthetic for the break in. Also recommended it in the GP 2 strokes, in the past.

They bin a serious amount of oil - it only does one meeting and then its out, in fact the whole Supersport thing is a serious expense.

Trials is definitely the cheapest form of motor sport. How does

[nigel dabster]

Had four new shercos on the trot and always started with 32:1 mineral oil for 1 gallon before Ipone at 75ish :1. Now there are rumours and anecdotes about Sherco mains but I've never had a head off yet, unless thats tempting fate? So whatever the reason it seems to work so why not?

[charliechitlins]

I've dealt with very few new or freshly-built 2-stroke engines, but dozens of 4-stroke, and break-in is tricky these days. It is almost impossible to break in a fresh set of rings with synthetic oil...the engine just smokes and smokes. Even standard oils are so slippery now (more so than 15 years ago) that it can take a surprisingly long time to seat fresh rings. I no longer slather rings with oil for assembly. Years ago, this would have been frowned upon, but a couple seconds of running dry, seats the rings much sooner.

Of course...I work with stone-age technology (iron bores).

I'd love to hear from somebody like Jon Stoodley who's in the trenches with modern 2 and 4 strokers every day.

[jrsunt]

2 strokes need fully synthetic oil, wheras 4 strokes usually take semi, mainly because it burns too much, although i'd recommend on race and track bikes. A yamaha R1, will use 1litre of fully synthetic oil in 1000miles, and this is in the owners hand book!!!

Back to proper bikes, that take some skill to ride correctly, I run my 04 mont at 62ml of fully synthetic oil to 5l unleaded. Some oils make the bike run better than others, The silkolene comp 2sx and the castol a747 seem to be the best.

[marlintec]

Ipone probably is the more used oil in UE trials but, anyone has experimented with Castrol (R2 or Biolube)? Some riders use this last just to 100:1, apparently without problems.

[spencey]

The HRC website mentions 80:1 for Dougie's bike so you'll probably find that's what the engines are jetted to run with.There's a website called Trials Austrialia which covers this subject in some detail in it's Tech Tips section.