modded predator 212

[liljj]

I have modded a predator 212 to drag race at my local track. Mods include fuel pump, billet flywheel, billet connecting rod +.020, mod 2 cheater cam, 18lb springs, high flow carb, air filter, aftermarket header and RLV muffler. The problem I am having now is that everytime I rev up the engine to about 3000 RPM and let off of the throttle it dies. It is almost like it drops RPM's so low it cant keep itself running. Any idea how to fix it? Thank you. :grind::thumbsup:

 

[Norcalputput]

What carb are you running
Pictures help a lot also


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[Commonrail]

What is the idle set on the carb? Most say set it to 2000 rpms. So if you're only getting 3000 RPM's and it comes down, I bet that's why it dies. That's just my guess.. gas engines are kinda new to me. I'm used to diesel stuff lol

 

[stephensimmons]

I would run a 26mm round side or a 28mm flat side. The round side is easy to tune but the flat side is more rewarding.

 

[minipex]

i used the exact parts that u did but used a gx390 carb. it was doing the same thing. put the stock carb with a #39 jet and e-tube and its perfect. i think the bigger carb is way too much for the mod 2 cam

 

[Bbeachmobile]

my parts list is similar but i have a dynocam f-278 and i run a pz26 slide runs pretty good still need to install the jet kit that came today but shes up to 53.9 mph with a 53 rear sprocket and a 13 inch tall tire now if someone could calculate my rpms that would be pretty awesome

 

[Commonrail]

my parts list is similar but i have a dynocam f-278 and i run a pz26 slide runs pretty good still need to install the jet kit that came today but shes up to 53.9 mph with a 53 rear sprocket and a 13 inch tall tire now if someone could calculate my rpms that would be pretty awesome

Are you running one of those quick change sprockets? I've got the 65 and 53 tooth version and put the 65 tooth on it and I keep chunking the chain off track. Did you have any issues? Are you running the stock tensioner?

 

[Prowler08]

The gx390 carb. On Alky with a Mod2 cam and a 1.3 rocker on the intake... Will kick some butt!!! FYI

 

[Bbeachmobile]

i had the stock Db chain on and it kept stretching and actually broke a couple times also it started eating the split sprocket so i ordered a Koch chain from amazon 10 ft of chain for 12 bucks and the quality is good i know there are better chains but ive had no problems so far i do have the stock tensioner

 

[Commonrail]

i had the stock Db chain on and it kept stretching and actually broke a couple times also it started eating the split sprocket so i ordered a Koch chain from amazon 10 ft of chain for 12 bucks and the quality is good i know there are better chains but ive had no problems so far i do have the stock tensioner

Thanks. I'm not sure what brand chain I've got. It came from OldMiniBikes with the plate engine mount, Max torque clutch and cover. I don't know if they use the stock #35 chain or not.. hopefully they didn't lol.