Derbi variant engine won't spin.

Just put the cases together on a derbi variant rebuild. Nothing turns except the crankshaft. I put a pedal on the pedal crank and it won't budge even a cm.

Anyone have a clue of what I should look at? I am about to break it back open a second time.

Re: Derbi variant engine won't spin.

Wesley Ambrosini /

Is the head off? I can stand on my pedals and the motor won't turn over without the decomp pressed in, but still turn it by the flywheel.

Did you use a gasket or just motoseal when you put it together?

Re: Derbi variant engine won't spin.

todd amundson /

Take it apart. The sprag/peanut/clown collar clip was not installed in its slot when you closed the case.

Re: Derbi variant engine won't spin.

Wesley Ambrosini /

> todd amundson Wrote:

> -------------------------------------------------------

> Take it apart. The sprag/peanut/clown collar clip was not installed in

> its slot when you closed the case.

Yeah that thing is a bitch even with possibly the best exploded diagrams known to moped-dom

Re: Derbi variant engine won't spin.

I used hondsbond to seal the case. It seems I had 3 washers instead of 2 behind a gear, removing I freed it up.

IMG_20201013_074205155.jpg
IMG_20201013_073535289.jpg

Re: Derbi variant engine won't spin.

I took it apart for a third time and excaberated a exterior crack into a full blown crack all the way through the case. It's a piston port tt and was driven like a dirbike so I got the case in banged up shape to begin with. Internals are flawless, while looking for a new case (used) someone offered me a 74cc Gila piston port that I'm gonna grab.

Re: Derbi variant engine won't spin.

Wesley Ambrosini /

Dude those cases need a gasket to shim the transmission correctly. Double check your assembly and cut or buy a gasket.. that poor derbi

Re: Derbi variant engine won't spin.

You don't know the heartbreak I had when I saw the crack... But I couldn't blame myself 100% cause it already existed prior, just on the surface exterior... At a stress point (pedals), my guess is they went off a jump at one point.

Re: Derbi variant engine won't spin.

Crack reference pic.

IMG_20201013_210316909.jpg

Re: Derbi variant engine won't spin.

Wesley Ambrosini /

Dude jb weld and run that shit into the ground

Re: Derbi variant engine won't spin.

If that's aluminum , why can't it be welded ?

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account