Transfer port questions

J

John the Chimp

New Member
Hey guys, as you all know the Grubbee 66cc. motor leaves alot to be desired. To say the least.
I had a ring break and stick the piston. Not repairable.
Now mind you the motor is less then a month old. Was broken in with 16:1castor 927. Then only went to 32:1.
When I asked about warranty I was told it was more expensive to mail it back to try to have the factory replace factory defected parts. Ok whatever.
So I just bought a new topend.
I know I need to clean the cast flashing out of the intake and exhaust ports and polish of coarse. Im also polishing the piston,wrist pin,rod end, and needle bearing.
Here are the questions. Should there be a bump or wall in the roof of transfer port? Or is that flashing? Should I remove it? I know pics would help but I am on my phone.
How much if any do I need to clean up the transfers?
Thanks in advance for any and all help or advise. I would like to help one of these azma sufferers breath better. Lol.
 
Your transfers should be level with each other and very very Smooth. Which they never ever are from the factory. Take some time with a dremel sanding -Disk-, fine grit, and chamfer all your ports. This will prevent rings getting hung, and keep oil on your piston.
 
I fished a long, thin strip of 300 grit sand paper through the ports and out through the cylinder and worked it back and forth over the edges of the ports, pulling it in and out in a wire saw fashion. No risk of a sanding wheel bucking and accidentally nicking the cylinder wall that way.
 
I just replaced my raw motor with a grubbe. I was a bit disappointed with the performance of this engine . I pulled the top end off cleaned the ports up milled the head down and now it runs like it should . The cylinder was a mess and look liked someone to a ballpeen hammer to it . I'm really surprised how well it runs now , so far I have put 70 miles on it and its still running ...xct2
 
headtrama said:
I just replaced my raw motor with a grubbe. I was a bit disappointed with the performance of this engine . I pulled the top end off cleaned the ports up milled the head down and now it runs like it should . The cylinder was a mess and look liked someone to a ballpeen hammer to it . I'm really surprised how well it runs now , so far I have put 70 miles on it and its still running ...xct2
Click to expand...

Update the motor blew up cool ........:-||
 
I havent had a chance to ride a whole lot lately. Still breaking in the new top end. I would like to get more then 1000 miles out of this one. Lol. Sorry to hear youve blown yours up. What was the cause?
 
Im not sure yet but something broke and went through the cylinder. I pulled the top end thinking i would find a broken ring or wrist pin bearing but they look good .Ill have to split the cases to see what i find down there .
 
xct2this is alot of happy time's motor drama, i have to say i bought one grubee motor it did not last more then 300km. was very upset. have my first motor that i bought from zoombicyles 3 years ago. i have beat the heck out of it, not going to say how as it might anger people. but anyways this motor still kicks a$$. I will Never buy grubee products again garbage in my opinion.
 
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