two stroke oil

[Pieter S]

There is a new two stroke oil on our market: Fuchs Titan TCW3
"Does not contribute to pre-ignition or spark plug fouling due to being ashless", the blurb on the container says. It is quite expensive (approx six pounds a litre). Is it worth using this in a Forty Plus?
My one Forty Plus (SJP 330 K5) is in a far better condition than the much newer FP 724 MM3. The latter was badly abused before I got it - gear box full of salt chrystals, and other horrors. The compression is much lower than that of the older one. What should the compression be before new rings and/or a new piston have to be filled?

[atoyot]

According to one manual, a 64cc engine (40 Plus, etc) should have compression of 135 lbs/inch squared. What that is in metric measurement I don't know. A 102cc engine should be around 60lbs/sq", says the same reference. If you have a hard time reachng those figures without putting a teaspoon of oil into the cylinder first, you may need rings, generally speaking of small engine repair.

As far as oil goes, any good outboard oil out today has to be better than even the best oils on the market back in the middle of the 20th century.

[Charles uk]

Has anyone ever seen a 40 series engine with more the 100lbs of compression? or is this another meyerism?

Brendan (webmaster) if you read this, is it possible to have a graph type (pie/bar) chart where we all could enter compression readings so we could form a picture of the top & bottom limits of each models compression ranges?

[atoyot]

Has anyone ever seen a 40 series engine with more the 100lbs of compression? or is this another meyerism?

I have to admit that seems a bit high for anything of this volume. I'll check mine in the next few days and weigh in on this in a more meaningful way....

-ted

[phil]

The best I have seen on a 40 series is 117psi, have another at 112 psi, 80 is more common. My best Century is 70, next 55, others usually 50. The one with 117 oddly enough has a very poor water jacket, not much meat left on bottom.