1972 gt750 cylinder head machining

72 Suzuki GT 750 J discussion forum:


1972 gt750 cylinder head machining

1972 gt750 cylinder head machining 
jaxjake22 said 2008-05-21 06:06 
 
if i machine 1mm of of the cylinder head the service manual claims that i should reach a compression of 150-160 psi. so i´m guessing that i will need to run premium fuel 92 octane? will i need to increase main jet size? i am trying to increase compression, i only have about 105 psi on all 3 and i was hearing what i thought was a top engine noise like piston slap when cold but when i removed the head i noticed all pistons were covered with carbon and i did not notice abnormal cylinder wear. so i´m lead to believe that the noise i was hearing was detonation. i cleaned off the carbon and would like to raise combustion temp to keep carbon off and run a little cleaner. i want to keep the engine reliable and somwhat stock. i know these were low compression engines. the service manual also claims that they are reliable up to 3mm machined off of the head but if 1mm raises compression to 150-160 psi, what will 3mm be? i suppose i would have to run race fuel and advance ignition timming? i just don´t want to destroy the engine from a slight modification. the bike is in pretty good shape and i inherited it from my father after it sat for about 18 years. i just would like to improve performance a little more knowing that i can raise compression fairly easy, but with what other modification will need to be done? 
 
<<Previous          Answer          Discussion overview          Report spam          Next>>

Comments, questions and answersEnter a comment or answer to this message

You can post your question, answer or comment as a guest. Or enter your e-mail to join the forum and get notifcations of new messages.

 
Title 		 
Signature
Optional e-mail
Enter your e-mail to join the forum and get notification of answers and new messages. You can unsubscribe with a single click. Bikez does not display, sell or misuse e-mail addresses.
Message text

Describe technical issues in detail to get quality answers. You can offer or request second-hand parts and equipment as a privat person. Bikez reserves the right to remove any improper or commercial content.
Accept that we store and display the message.  

 

More 1972 Suzuki GT 750 J information

Our discussion forums are intended for short messages. We also welcome more extensive motorcycle reviews.

Bikez also recommends that you check out the technical data and the riders' rating for the 72 Suzuki GT 750 J. You can also rate it yourself. Use our efficient motorcycle classifieds to sell or buy this bike. Your motorbike gets a high quality presentation. Ads are free.