Hey

Brent436

Brent436

New Member
Hey everyone,

I recently put a Grubee 48cc motor on my bike. I've had some problems so I came looking for some help. I graduated top of my automotive class in tech school and have a lot of experience with engines. I'm kind of embarrassed that I have to come asking for help but I just can't seem to get the motor running.

The first time I tried to start it the motor took a while to start up. When it finally started it ran real rough and i would have to keep hitting the throttle to keep it running. While it was running it seemed to backfire a lot. After that I stopped the engine and couldnt get it started again. I Have spark and its getting gas. I have sealed the carb and am waiting for the RTV to cure to try it again. Any suggestions to what else could be the problem would be appreciated. Once I'm considered an active member I will post this in the troubleshooting section. Thanks for all your help.

-Brent
 
Welcome Brent,
You've come to the right place for help and no need to feel bad about asking for it. We all had to start where you are. The Professor is right; sounds like a lean condition most likely from an air leak in the intake/carb area. Get back to us if this doesn't take care of your problem. We're here to help.
Tom
 
Back again guys,

Thanks for your help but it still doesnt run. The carb is all sealed up now. I tried starting it this morning but it still wouldnt start. i opened the carb up and the black c-clip was at the third notch from the top. I've read in other threads that the best setting is second from the top so i moved it there. Tried to start it after that and it fired once. After a little while of still trying to start it, it fired once more. Since then I havnt been able to get it to fire. I'm in Massachusetts right now so its cold but its above freezing so i figure it should be able to run. Does anyone have a recommendation to where the idle screw should be set at? I've tried 4 1/2 turns out like the manual recommends and I've tried 3 turns out like other people on other threads have recommended. I'm gonna try some starting fluid now. Any help is greatly appreciated!
Thanks for the help,
Brent
 
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Another quick question: if i take the throttle cale part of the carb out (with the plunger thing out) and turn the motor over, is fuel supposed to come out of the hole looking straight down into the carb? From what i understand thats where the fuel comes out of and none is coming out on my motor.
Thanks again,
Brent
 
Hello again,

Brand new 48cc Grubbee Skyhawk still isnt running. I replaced the stock plug with a champion E3 Diamond fire plug. I closed the gap to .020 as suggested by other troubleshooting threads. It fires a lot more and is very close to starting. At this point I'm lost as to what i should do to get it running. The best guess that i have is that its a carb problem. If you have any suggestion as to what i should do please say something. Thanks!

Brent
 
Hey,

The plug is wet after trying to start it a few times so it is getting gas. I suppose either later tonight or tomorrow I'll check the float height and adjust it like you said and try starting it again. Thanks for the help.
-Brent

Edit: Right now im running 18:1 like the instructions say for break in. Ill add more gas to the tank to lower the percentage of oil. I will probably try this before opening the carb up to check the float. Thanks again.

-Brent
 
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Do we take out the plug ,hook up the wire,lay the plug on the head and spin the motor to see if the mag is throwing a good spark(?)
 
Yeah thats how you check for good spark. You just have to make sure the electrode is grounded to the engine block. I recommend buying a better plug than the stock plug that comes with it. I replaced mine and its got a lot better spark than the stock one.
Hope this helps,
-Brent
 
I was helping another rider troubleshoot a similar no start problem and it was the ignition. Plug out of the head had great spark but would not fire in the head. He replace the CDI and Mag and then it ran. Don't know for sure which one was the actual problem.
 
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