GT750 Cylinder head and Cylinder block Identification

Need some help? Put your question up here. Many years of experience on the board to help you get up and running.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
User avatar
jaycee69
Around the block
Posts: 58
Joined: Sun Jan 15, 2012 11:33 am

GT750 Cylinder head and Cylinder block Identification

Post by jaycee69 »

Hey does anyone have a link to a site that has the differences in the cylinders and cylinder heads from year to year?
I found one a while ago but cant seem to relocate it.

Regards,
Justin
73 GT550 K
77 GT750 B
88 Yamaha YSR50 (Street Legal)
91 Yamaha YSR80 (Street Legal)
User avatar
oldjapanesebikes
Moto GP
Posts: 3229
Joined: Sat Feb 07, 2009 12:43 am
Country: Canada
Suzuki 2-Strokes: GT750(Jx3,L,M,A,B),T500
Location: Ontario
Contact:

Re: GT750 Cylinder head and Cylinder block Identification

Post by oldjapanesebikes »

I happen to know one ! :D :D Take a look here. 8)
Ian

If at first you don't succeed, just get a bigger hammer !
User avatar
jaycee69
Around the block
Posts: 58
Joined: Sun Jan 15, 2012 11:33 am

Re: GT750 Cylinder head and Cylinder block Identification

Post by jaycee69 »

Lol isnt that your site? and i did find the info i needed. turns out 76 and 77 barrels and cylinder heads are the same. its funny i have poured over that site a bunch of times and missed that section. oh well! It is also nice to see another Two stroke fan in Canada!

Regards, Justin
73 GT550 K
77 GT750 B
88 Yamaha YSR50 (Street Legal)
91 Yamaha YSR80 (Street Legal)
User avatar
oldjapanesebikes
Moto GP
Posts: 3229
Joined: Sat Feb 07, 2009 12:43 am
Country: Canada
Suzuki 2-Strokes: GT750(Jx3,L,M,A,B),T500
Location: Ontario
Contact:

Re: GT750 Cylinder head and Cylinder block Identification

Post by oldjapanesebikes »

There's a load of us up here - the smoke is handy in the summer as it keeps the mozzies and black flies down ! :D What part of the country are you in ?
Ian

If at first you don't succeed, just get a bigger hammer !
User avatar
Suzukidave
Moto GP
Posts: 3980
Joined: Fri Oct 24, 2008 5:55 pm
Country: US
Suzuki 2-Strokes: GT750 x2 97 -1200 Bandit 86 GSXR1100
Location: Lancaster Pa.

Re: GT750 Cylinder head and Cylinder block Identification

Post by Suzukidave »

Without looking at Ian's site i believe there are 4 different cylinders and maybe 3 different heads not counting the 2 piece head ?
the older i get the faster i was
User avatar
oldjapanesebikes
Moto GP
Posts: 3229
Joined: Sat Feb 07, 2009 12:43 am
Country: Canada
Suzuki 2-Strokes: GT750(Jx3,L,M,A,B),T500
Location: Ontario
Contact:

Re: GT750 Cylinder head and Cylinder block Identification

Post by oldjapanesebikes »

Suzukidave wrote:Without looking at Ian's site i believe there are 4 different cylinders and maybe 3 different heads not counting the 2 piece head ?
That matches my count Dave 8)

Correction: four heads plus the split head, so five total.
Last edited by oldjapanesebikes on Fri Mar 23, 2012 2:05 pm, edited 1 time in total.
Ian

If at first you don't succeed, just get a bigger hammer !
User avatar
jaycee69
Around the block
Posts: 58
Joined: Sun Jan 15, 2012 11:33 am

Re: GT750 Cylinder head and Cylinder block Identification

Post by jaycee69 »

I am In Nelson, British Columbia. and what years were the heads different? 72-73,74-75, and 76-77? and was there any benefit to the Split head design?
73 GT550 K
77 GT750 B
88 Yamaha YSR50 (Street Legal)
91 Yamaha YSR80 (Street Legal)
User avatar
oldjapanesebikes
Moto GP
Posts: 3229
Joined: Sat Feb 07, 2009 12:43 am
Country: Canada
Suzuki 2-Strokes: GT750(Jx3,L,M,A,B),T500
Location: Ontario
Contact:

Re: GT750 Cylinder head and Cylinder block Identification

Post by oldjapanesebikes »

jaycee69 wrote:I am In Nelson, British Columbia. and what years were the heads different? 72-73,74-75, and 76-77? and was there any benefit to the Split head design?
Nelson - not so far from here, and I know of a couple of GT750's living in Vernon which is (sort of) in your area !

There were three head designs in the first two years of production, including the split head, and the 'why a split head' question is as yet unanswered. Gunnar wrote a section on it which can be found here.. The head looked the same from the late 'K' onwards with a small change happening in 1975 which in theory boosted the compression ratio. Take a look at service bulletin GT-7 found here. I say in theory as you also needed to use the thin head gasket to get the full effect - I suspect the thicker after market gaskets pretty much negate the value of this so for all intents its a wash. If you just want to ride it - I wouldn't worry about the differences. If you want to play, then do some searches on the board as there are lots of things you can do to rapidly deplete your bank account ! :D
Ian

If at first you don't succeed, just get a bigger hammer !
Post Reply