I have some out of production glow engines that need o-rings for the needle valve and other sizes. Does anyone know a good source for o-rings that I could order by measuring the dimension with a caliper. Also looking for a manual for a Magnum Pro SE 46. Thankyou.

Do you have a hobby shop near you that you can go to? Lots of r/c cars use very small o-rings in their shock absorbers. That is a good source for them. Their are normally 'shock rebuild kits' at the hobby shop and you can look through them to see if any of the o-rings will work for you.

I had a needle valve problem with my OS91FX (they are known for it), I ordered a set from my LHS but in the mean time I made one from a piece of fuel tubing. I had a big selection of off cuts and found a type that fits just right. The trick is to slice it just the right size with a sharp hobby knife. It has to tightly full the gap made for the o-ring and has to be slightly thicker than the needle valve shaft. Then the original o-ring arrived I installed it but replaced it again with my fuel tubing type because it works better : no chance that the needle can vibrate in the housing.

Also you can use very fine sandpaper on outer dia. to fit it if gets thicker than needed.

once i made O ring for needle from fuel piece of fuel tubing. worked well

Don't use ORings from some auto place or something that is not RC related. The fuel eats the rings.

Viton is the material that is fuel proof, but some people have had good luck using regular o rings when the viton ones weren't available.

I found a web site with a google search - www.allorings.com

You might have to buy a bunch at a time, though.

I would first google for an o-ring chart, you'll get a list of all the standard "dash number" o-rings which are based on imperial measurements. Individual suppliers should also have a list of metric o-rings which can get you out of a pinch too.

http://www.mcmaster.com has online information from which you can learn a lot. Just type "o-rings" in the search box. Then look over the Buna o-ring info and you'll see how top select based on dimensions. They are a killer supplier, mind you ordering $1.15 of o-rings from them doesn't work. But if you are like me after you search around on their website and see all the stuff they have, it is hard to keep the order within sane limits..

You can also often request an o-ring guide from local industrial o-ring suppliers. Most towns/cities with aqn industrial sector of any significance will have an outfit or two that handles seals. I don't mean the zoo..

MJD