Laura M56 RPM

I've been inspired by the "Two stroke tuner's handbook" and want to make my own expansion chamber so, I need to know the rpm range of my engine. I hooked my 12 volt automotive analyzer (dwell tach) to a 12 volt battery and connected the spark plug cable lead to the spark plug wire on the ped. My dwell tach only goes to 6,000 and the clutch on my ped doesn't even fully engage until 4,200. Does anybody know what kind of rpm's a Laura m56 spins? I've shaved the head, pulled the bronze restrictor out of the carb, drilled the main jet, and took off the exhaust baffle. Stock speeed was 25 ish, I now hit 32. My guestimation is about 12,000.

Re: Laura M56 RPM

usually moped engines stock top out around 6-7k, i've got a lot of work done and i'm just starting to push 10. for that engine i'd say you should do your calculation using 7500 rpm.

Re: Laura M56 RPM

The last Batavus I tached was going about 3800-4000 at 30 mph. They do not turn very many rpms at all. If you are using a car tachometer then it might read every pulse and think its going twice at fast as it actually is (4-strokes fire every other rotation and 2-strokes every time), so I'd say your turning half as many as you think you are.

Re: Laura M56 RPM

terrible engine to tune

Re: Laura M56 RPM

Duh. When I was thinking of hooking up an old automotive tach to the coil I realized I'd have to make a correction for the number of cylinders.....I didn't even think of two vs four stroke. My observations make sense now.

Thanks Guys.

At least if I screw up when I get to the porting part of this project I won't be destroying a desirable piece! I've never ported a two stroke other than a couple model airplane engines.

Re: Laura M56 RPM

haha yeah, two stroke, fires every revolution, needs to be divided by two, i was wondering about that because 4000 is pretty high for a clutch to grab at. hehe

Re: Laura M56 RPM

yeah 12000 no way 7500 on stack motor probably not as said they run around 3-4-5 k rpm if ure lucky but mine will be around 9k or more but mines a m48

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