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Discussion Starter · #1 ·
Hi there,

I wonder if there is anybody who can help me with a GT750 I am putting back together

It is a 1975 GT750M.
On starting the bike revs upto about 6,000 and would probably rev higher before I turn the bike off.
I have been unable to get the revs down to tick over.
The throttle cables have been oiled and work smoothly. There do not appear to be any vacuum leaks.
I am using the stock airbox. Seems to be about the desired amount of freeplay in the cable (3mm).
Carbs have been sonic cleaned and blown through with a compressor. Floats, jets, needle valve all look OK.
Throttle slides seem to be moving freely. Air screws are 3/4 turn out. The carbs are the CV type.
Before I remove the carbs again can anyone give me any pointers where I may be going wrong or have missed something.
Many Thanks
Mark
 

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Without checking I think that is a two stroke. Any air entering into the crank shaft area can cause hi reving. It may be the crank shaft seals, or the parts that are holding the carbs in place.

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Discussion Starter · #3 ·
Hi Uncle Krusty,

I can confirm that it is a 2 stroke. Carb boots look good and fit very snug
I did wonder about the crankshaft seal but with other bikes I have found that when they leak they cause an uneven tick over, I have never known a bike to rev so high due to the crankshaft seal but it may well be possible.
Have you or anyone else out there had a failed seal causing such high revs?

Thanks


Mark
 
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