HI
I know some of you guys use 50/50 unleaded fuel /avgas. Does anyone use lead additive in fuel to help lube as avgas not easy to get here.

Mod edit: Spelling and clarity
FY

Doesn't need the lead for lube. That's what your stroker oil is for.

Are you looking for a lubrication increase and octane increase or....?

50/50 avgas/ULG will increase octane and also slow the burn, but you could lose power, not gain power, by increasing the fuel octane.

If the engine is setup (compression, ignition etc) to run let's say 91 octane fuel then you will lose power by throwing in avgas.

There's lots of variable. You need to use the fuel your engine needs, not necessarily what the guys at the track are using.

If you want to increase the octane of a pump fuel then you can add an aromatic such as toluene or xylene, but they're expensive and to be honest the fuel companies blend in such a large percentage of aromatics these days that it doesn't make too much difference.

If the bike runs well now with whatever fuel you're running then leave it as it is. Or you'll end up chasing compression ratios and ignition settings to get the best from it.

thanks Matt
I was thinking as extra lube. I run 98octane pump fuel and was thinking additive might make it a bit less likley to seize.

No. Getting the carb settings right will make it less likely to nip.

Don't rely on any so called additive to reduce the chance of locking it up. If it's jetted right it won't seize.....famous last words

Whilst I would not have the nerve to argue with Matt about setup, 50/50 Avgas/Unleaded is less likely to seize than straight unleaded if the jetting is less than perfect for the conditions.
It will also allow you to increase compression and otherwise tune further with less risk of detonation.

The only true lead additive I know of is Tetraboost, more than one guy on twostrokes.com has successfully run a leaded race fuel GP 250 on it.
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Ok, I'll go with Fontyyy to a point. Avgas will go a size too lean without nipping up, whereas ULG might not, but........what is it we're trying to achieve here?

If you don't want your bike to seize then put it all back to stock, run the manufacturer's recomended settings, stick pump fuel in it and ride around all day having fun.

If you are running lean (as is), then by adding avgas you will reduce the risk of seizing mainly thanks to the avgas requiring a leaner mixture for complete burn compared to pump fuel, in effect a richer mixture. Also, the higher octane will reduce the chance of detonation.

If you're running rich now, mixing avgas will make it richer. Not a good idea.

Are you racing the bike? Do you need every last pony that can be squeezed out?

If not then pump fuel, correct carb settings and a quality 2 stroke oil will give you all the pleasure you need.

So many times engine problems can be traced back to bad carb settings.

Matt@TYGA wrote: but........what is it we're trying to achieve here?

Winning a championship by finishing every race
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Be carefull when you swop from race fuel to unleaded pump fuel for example . Your jet sizes change !