2 stroke bicycle engine - getting richer with break-in??

Pablo · #1 03-10-2008, 12:54 PM

Just as the title says, did your 70cc 2 stroke engine - get richer with break-in??

I'm just about done with my first tank of fuel (as a time measure) and the engine is still somewhat breaking in. The only problem now is that it's getting progressively richer - to the point of me wanting to go messing with the needle. Plug is wet with fuel and when warm if I wick on full throttle it really bogs and sops with unburned fuel.

deacon · #2 03-10-2008, 01:27 PM

Then move the needle. There doesn't seem to be any rules. If it isn't doing right try it you can always move it back.

Can Harm Hen · #3 03-10-2008, 01:29 PM

Have you tried changing the spark plug and wire? My spark plug wire actually fell apart after the second tank of gas. Thanks to cruiser, who sent me a new one!

Bikeguy Joe · #4 03-10-2008, 04:37 PM

I'll say the plug is definitely a real piece....try a new NGK first, then if it's still rich, change the needle.

It is possible that it can "get richer" since, after the engine starts to break in, will make more compression and draw a better charge into the cylinder each stroke.

Also, check your air cleaner element, mine got full of crud and spit back fuel relatively quick.

Bikeguy Joe · #5 03-10-2008, 04:38 PM

BTW- break in is usually done after a few hundred miles. (two or three tanks at least)

Pablo · #6 03-10-2008, 07:28 PM

Plug (NGK B5HS) (and wire (ala cruiser)) are fine.....but does get fuel wet when it bogs.

I know the engine isn't fully broken in.......I may try the leaner notch.

deacon · #7 03-10-2008, 07:30 PM

might not help but it can't hoit

Bikeguy Joe · #8 03-11-2008, 04:24 PM

Didya check the air filter element?

Pablo · #9 03-11-2008, 04:28 PM

Happens with no filter. I will however check my carb....something may be goofy with it, I think it's leaking more fuel than normal....

Bikeguy Joe · #10 03-11-2008, 04:38 PM

Float sticking?