It says "Do NOT use unleaded" but it is 2-Stroke

[SumpChump]

I recently aquired a 1978 Moped with a Puch motor. It is 50:1 fueled but it also says not to use unleaded. I thou lead was just for traditionally valved 4 cycle engines? It has probably been run lead-free since 1984 or so. I think the warning was to prevent folls from using coleman fuel back then.

Best to add a lead substitute? Or just run a higher quality ashless spec'd 2-stroke oil?

 

[John_Conrad]

should be alright with unleaded.

http://www.mopedarmy.com/wiki/NOTE:_DO_NOT_USE_UNLEADED_GASOLINE

i'm sure you found that on research. interesting it say's the motor has no valves...

 

[demarpaint]

IIRC leaded fuel was still around then, but the lead content was greatly reduced. It wasn't until about 1996 that lead was totally out of fuel in the USA.

A lead substitute wouldn't hurt.

 

[Silverado12]

Lucas fuel treatment is a lead substitute.

 

[RoadRaceJosh]

Did you read the mopedarmy.com link? I agree with the no white-gas warning. That stuff has an octane rating suitable for about a 4:1 compression engine. A better warning would have been to use regular grade motor fuel only. 2-strokes don't need lead so long as the octane requirement is met and lead has problems beyond pollution and pollution controls. I would NOT use any lead substitutes. That's just asking for combustion chamber and spark plug deposits.

 

[lars11]

it has the piston working as a valve, if that's what you mean. No reed valve or anything else.
Originally Posted By: John_Conrad
should be alright with unleaded.

http://www.mopedarmy.com/wiki/NOTE:_DO_NOT_USE_UNLEADED_GASOLINE

i'm sure you found that on research. interesting it say's the motor has no valves...

 

[Kestas]

I had the same warning on my 1978 Montgomery Ward chain saw. I also ignore it. The chain saw is still in service.

 

[Robenstein]

If the engine is constructed of good materials, using unleaded in a vehicle built in the leaded era won't hurt.

Ran an old mid 60's Buick V8 for a long time hard on regular unleaded 89 octane gas. Only problems I had were because of ethanol.

 

[NH73]

Just like they tell you that you should use a API SL oil today.

 

[Cujet]

The leaded fuel does add to crankshaft life. More specifically, the con rod big end roller bearing. Racing bikes experience 25% to 100% longer bearing life with leaded fuels.

In addition, some of the components of pump unleaded fuels can cause a touch more 4-stroking at partial throttle settings. When compared to equal octane leaded. That clean, crisp feel is muted with some unleaded fuels.

 

[CT8]

I remember all the two stroked used to have a use leaded gas way back then.