brand new PHATMOTO engine ceased after 2 miles.... replacement ideas/advise



I recently purchased the matte black 2020 Phatmoto rover 79.5cc 4 stroke bike from only ran into a couple small issues at first. like the connecter that connects the kill switch to the engine was two different sizes. the female was way too big for the male connector, luckily i had i larger male connector to fit it already, so i just had to cut off the small one and replace it with the right size. and i ran into a couple more things not worth complaining about... i didn't do any mods or governor bypass tricks or anything... i put oil in it, filled it up with gas and took it for a short ride (less than a mile) and the next day did the same, , no issues, but today, i rode it to the store (less than a mile from my house) and just as i pulled into the parking lot, it stalled out... i tried to pull the starter and it was difficult to pull the first time and didnt start and when i tried again it was more difficult, i tried a third time and (nope) the starter is stuck, it wont pull... so i had to pedal home... and i tried all kinds of stuff and i couldn't get it unstuck... so i called gasbike and when i finally talked to someone they said i probably was too hard on it... which is bullsh*t i think... they said i need to buy another engine... so i was looking and its $150 for a new phatmoto 79cc engine. for a predator 79cc from harbor freight its $99 but i'm not sure what else i would need to make it fit the phatmoto frame. gasbike sells a kit for it for 99 dollars... so all together it might cost me over 200... gasbike also has a 196cc Electric Start 6.5HP Gasoline Engine - OHV 4-Stroke for $189. does anyone know if that would fit the phatmoto rover frame? and is that engine any good... i like the fact it takes a key and also has an electric start. any advice on what i should do would be appreciated. thanks
If I'm not mistaken, the engine is shipped with shipping oil or assembly lube so theres a slim chance that anything will rust etc. I always make sure to drain any oil from shipping or assembly out, only then adding the right oil to spec.


Well-Known Member
Jun 22, 2007
An engine is a masterpiece of engineering!

I find joy in finding what makes things tick.

Here's what I'd do:

First I'd remove the valve cover and side cover, to monitor mechanical movements.

Check to make sure no loose parts in head or crankcase.

Remove sparkplug, jam the cylinder with rope.

Remove pull start, see if working properly.
Spin engine counterclockwise(CCW), until it jams. Remove the flywheel and check to see if the key is intact.
Reinstall flywheel and starter cup to ease turning the engine.
Remove chain, check if clutch is
Remove rope, drop 8" long nylon tie into cylinder(This is to find top dead center{TDC}, without damaging cylinder.).

Turn starter cup slowly, watch cam, crank and valve action.
When piston reaches TDC, the nylon tie will let u know.

Determine if the flywheel timing mark is near CDI..

Adjust the CDI to specs.

Check to ensure cam timing dots line up. Readjust, as needed.

Set valves with feeler gauge.

Turn engine by hand clockwise(CW) several times, monitoring all moving parts.

Everything should spin easily.

Reinstall sparkplug, spin engine once.

Engine should feel tight, but still spin.

Reinstall pullstart and start the engine

The engine should now fire up after a couple pulls.


New Member
Apr 6, 2021
I bought a phatmoto and love it. I upgraded my back sprocket to 36 tooth and seen then I wasn't getting enough air to the engine. I went to a go cart shop and bought a cold air intake for it and it seems alot better as far as to getting to max rpm. as a compromise I've purchased a 42 tooth sprocket to keep my torgue and now loose to much on my top end. I'm still wanting to do more. I've looked into the harbor freight engines and they do have one that will work but I'm not gonna bother until this one blows up. I've drivin mine about 1000 miles and so far so good.