Video Inside - Modified Predator 212cc Mid RPM Funky Misfire

[surfer_mayne]

Hey all, my engine is running way funky and here is a video to show it. Mods list and troubleshooting below.

[video=youtube;dayer8-YqY0]https://www.youtube.com/watch?v=dayer8-YqY0[/video]

Predator 212
All internals stock
Governor Delete
Oil Sensor Delete
Mikuni Carb Swap
(Sometimes) Open Header

I have cleaned dozens f carbs in my time, and i've cleaned this one 3 times with no improvement each time.
I tried a new plug (Photo of plug taken directly after video)
I adjusted the valves to .002 in and .003 ex



Is it time for a new 212?

 

[ole4]

Do you have the enrichiner turned off? How is the carb set up?

 

[SAS289]

Did it ever run ok after the carb swap or did it start this behavior just after the carb swap?

If you do not think it's a carb issue then verify that by putting the original carb back on. That at least would tell you if it is an engine or carb issue. Then you could go from there.

 

[surfer_mayne]

Do you have the enrichiner turned off? How is the carb set up?

Enricher meaning choke? Yes I turned that off - in the video I had let the bike idle for a few mins to get warm as well.

 

[surfer_mayne]

Did it ever run ok after the carb swap or did it start this behavior just after the carb swap?

If you do not think it's a carb issue then verify that by putting the original carb back on. That at least would tell you if it is an engine or carb issue. Then you could go from there.

Yes this carb setup worked wonderfully and made tons of smooth power until recently.

The gov is off as i mentioned and I would run the thing pretty hard - could over revving do this? bent valve or something similar?

Edit: I still do have the old carb, its that i had to remove the studs for the mikuni carb install.

 

[trinik7597]

When you removed the gov. Did you take it all out ?? Stock rod ?? I hear something funky in your bottom end even though videos are hard to gauge how it actually sounds .. that plug says you are running extremely rich or have oil in the combustion chamber

 

[surfer_mayne]

When you removed the gov. Did you take it all out ?? Stock rod ?? I hear something funky in your bottom end even though videos are hard to gauge how it actually sounds .. that plug says you are running extremely rich or have oil in the combustion chamber

Yup full governor removal with a self tapping bolt in the governor arm hole. 100% stock internals. I swear on idle it sounds like it always has, the extra loose change noise is coming from the clutch being worn out.

I have a feeling im gonna be taking this thing apart just for kicks and buying a brand new one - not a terrible hit to the wallet

 

[trinik7597]

And yes over reving can cause major issues if you have not upgraded springs and such you could pretty easily float a valve or even drop one .. or gal the stock rod on the crank journal

 

[trinik7597]

What about the gear and rod behind the flywheel ?

 

[surfer_mayne]

What about the gear and rod behind the flywheel ?

If your referring to the governor internals you access by removing the cover on the output shaft side of the motor, then yes, I did remove them. If there are more parts that are accessed by removing the pull start cover than no, those did not get removed.

Thanks for all the questions, I can tell you guys are trying to help!