Icebear maddog 50cc issues....all of them!

Hey guys, I'm new to this thread but not to mopeds. I currently have a maddog 50cc Gen 3. I got it back in 2018 and have hd very little issues until now. Last Oct as I was riding home from work I heard a loud pop followed by smoke and that was that. I'm not really sure what happened but I think the oil pump went out.

I have been rebuilding and breaking down this engine since Nov and I cannot get it to start. I installed a bbk, new cam, seals, chain and guides, a few bearings, pretty much everything you can think of. It seems like every time I put it together and try it out something else is gone. I've now ordered a fuel pump and carb. BTW I'm only getting 50psi of compression and the kickstart is stuck. The engine will turn over once then stop and then try again with the plug in, without plug I am able to check the compression. I have a new starter,plug, coil, stator, the works and no luck.

I'm about to throw in the towel bc I cant throw anymore money at this thing. If anyone has any advice just shy of burning it down, please let me know.

Thanks,

Chris

Re: Icebear maddog 50cc issues....all of them!

Unfortunately this is a vintage 2 stroke pedal moped forum and you have a modern chinese 4 stroke scooter so we won't be of much help. Try finding a Chinese scooter site, good luck and hope you're back on the road soon!

Re: Icebear maddog 50cc issues....all of them!

Chris McKenzie /

Thanks man

Re: Icebear maddog 50cc issues....all of them!

Tweaker trash /

Dude It needs a new top end! You blew it up, it’s burning oil

New piston and rings

Re: Icebear maddog 50cc issues....all of them!

Dirty30 Dillon /

> Tweaker trash Wrote:

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

> Dude It needs a new top end! You blew it up, it’s burning oil

>

> New piston and rings

Dude. Read.

He replaced the topend.

To me it sounds like you bit off too much. Anything you've touched PLUS the peripherals will need to be checked over again. Could be too much compression, could be air leaks, could be failed jetting, etc.

What is your compression? Have you done a leak down test? How did you compensate your jetting?

Re: Icebear maddog 50cc issues....all of them!

A single rotation indicates that the valve timing is off .

Re: Icebear maddog 50cc issues....all of them!

I'm sure it says up there he is getting 50psi of compression.

Re: Icebear maddog 50cc issues....all of them!

Tweaker trash /

> P D Wrote:

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

> A single rotation indicates that the valve timing is off .

Or valve lash

didnt say he put a new top end in?

Re: Icebear maddog 50cc issues....all of them!

> Tweaker trash Wrote:

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

> > P D Wrote:

>

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

>

> > A single rotation indicates that the valve timing is off .

>

> Or valve lash

>

> didnt say he put a new top end in?

If he had it down that far , it's easy for a newb to not get everything lined up or set perfect .

Re: Icebear maddog 50cc issues....all of them!

what PD said. I agree fully. take the head off and make sure you're lining up the timing marks on the cam chain. I feel pretty certain that's your problem, and hoping you havent bent any valves or damaged anything else trying to start it with that set incorrectly.

Do that first and formost, i'd give a really high chance that your problem is the valve timing, timing chain set in the wrong position on the cam sprocket.

Re: Icebear maddog 50cc issues....all of them!

Chris McKenzie /

Thank you guys for the advice, I'm still working at it. I definitely bit of more than I could handle. I feel pretty good about the timing as I've checked it several times and it seems dead on. I'm going to check the valves and possibly pull and replace them.

Im caught in a catch 22 now, a mechanic said he was going to charge $40 an hour and had to find the problem whereas finding this extra longcase 50 is nearly impossible. Thanks again for the info and I'll keep you updated.

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