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Old 09-05-2011, 11:10 AM
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richirich richirich is offline
Motorized Bicycle Elite Member
Join Date: Aug 2011
Location: Port Angeles, Washington
Posts: 297
Default My review of the GT5_A Superhawk

Let me start by saying that i was repacing my 58cc phantom edition motor with the GT5_A, not that there was anything wrong with it. I just wanted to have a broke in back-up motor. As far as hte GT5-A is concerned is to know it is set up for a small down tube frame the other motor was for large frames.So i had to order the large frame adapter from SBP. ordered it on thursday night, had it on saturday)"SBP is great". In the meantime i replaced all the hardware from the screws to allen socket head cap bolts. I replaced the studs with 5.5 grade. Sunday morning i was ready for the test fire up. filled the tank with priemium fuel and 20:1 Castor927 pro series oil. I went alittle up my alley and got rolling then poped the clutch and wham it fired right up.i went around the block and it feels very powerful, unfortunatly i heard the exhaust leaking. i had a custom exhaust already that was set up for the other motor. the angle on the head was a little different but nothing the dremel on the pipe couldnt handle. i checked the torque on everything and it seemed fine. went for another ride all was going well untill i started to go up an incline then heard the "wap wap" of a leaking head gasket. I had replaced the head studs with 5.5 gade studes and had checked the head on fine sandpaper so i know that was ok. i started with 10ft # so i upped it to 12FT # took it out fror another ride. same thing when i would go up a slight incline and the compression would have to work (wap wap ) leak. so i tried to go to 14 FT# on the torque and the studs stripped . i guess 5.5 is only good for 12# So i would have to assume with the high compression of this motor that a realitivly high torque is needed. so now i have to wait a coulple of days for new head bolts from SBP. on my other motor i serously milled the head for high compression and replaced the studs with high grade SBP ones and had to torque to 17FT# on 6mm bolts with no leaks no problems.
But overall everythging else has been just fine. i am higly impressed with the power of this motor. even at quarter throttle and a leaking head gasket it pulled me up a hill with ease.
Another good thing about this motor is the large intake and exhaust ports. There hugh compared to normal motors. It comes with a matched intake but the exhaust is big, be prepared to break out the dremel and do some major grinding if you want your pipe to match.
Overall i like it, ill post the results of the head stud change in a few days. I hate waiting for parts. Sometimes it feels like your waiting for parts more than you get to ride...
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