GT 750 engine teardown

[1000J]

I have a stupid question or or perhaps a difficult to really answer question, I have a 74 Gt750 that has been in the same garage since 1981,bought it cheap,put fuel in the rusty tank,used battery,hit the choke and for some reason it started,good enough reason to keep it and put it back on the road,anyway it's filthy and covered in oil,so I've torn it apart and have most of the restoration done just paint and engine left, the engine being the stupid question I spoke of earlier.Too oily to leave together so it came apart today,split the cases,have some obvious parts to deal with like the cracked water pump gear and some broken bolts etc but I'm asking if there is anything I should look for,change,replace,visually everything looks fine,gears,shift forks,clutch basket,no wear or damage on anything...I hear about crank seals but really don't want to spend money on rebuilding the crank,pistons look good,rings were free,one wrist pin was tight to remove the other two easy,standard bore,cylinders look good etc...Sorry for the long story but I have no experience with these Gt's.Thanks for any insight.

[oldjapanesebikes]

Another Canuck ! Welcome !

To your question - that is like asking 'how long is a piece of string ?' Now that you have the crankshaft out, with its 40 year old heat hardened engine seals I think personally you may not have a lot of choice but other than to replace the crank seals. Having disturbed them, I'd put money on them failing soon after you put it back on the road. The other common issue with engines that have sat for long periods of time again is on the crankshaft and is corrosion pitting on the main and big end bearings which you can't check unless the crank is pressed apart. Obviously failure of the big end makes a big mess.

For the rest of it (gear box, clutch etc) if there is no obvious wear then it should be good for another 20 years. The water pump gear is still available from Suzuki Canada (at least was when I last checked earlier this year). Crank pins, seals and most of the main bearings likewise are still available, but prices are usually better (not always) in the US.

[1000J]

Another Canuck ! Welcome !

To your question - that is like asking 'how long is a piece of string ?' Now that you have the crankshaft out, with its 40 year old heat hardened engine seals I think personally you may not have a lot of choice but other than to replace the crank seals. Having disturbed them, I'd put money on them failing soon after you put it back on the road. The other common issue with engines that have sat for long periods of time again is on the crankshaft and is corrosion pitting on the main and big end bearings which you can't check unless the crank is pressed apart. Obviously failure of the big end makes a big mess.

For the rest of it (gear box, clutch etc) if there is no obvious wear then it should be good for another 20 years. The water pump gear is still available from Suzuki Canada (at least was when I last checked earlier this year). Crank pins, seals and most of the main bearings likewise are still available, but prices are usually better (not always) in the US.

Thanks Ian that's what I'll do, everything else looks good but when I inspected the seals I found one to be too loose and out of round,the center was torn away so now to figure out where when and how to get this crank rebuilt.

[oldjapanesebikes]

......... so now to figure out where when and how to get this crank rebuilt.

If you are close to the border, Bill Bune in the US is good. We have a fellow just south of Calgary who does all of mine and if you are in eastern Canada then I'm sure there are options. Cliff (on this board - I forget his 'handle' ) and others may chime in with some suggestions for places in Ontario, and if you are in the CVMG you can always post over there as well. The only crankshaft bearing Suzuki doesn't still sell is 09262-30013 but they can usually be bought from Paul Miller in the US or from Reiner in Germany if you need one.

[Cliff]

......... so now to figure out where when and how to get this crank rebuilt.

If you are close to the border, Bill Bune in the US is good. We have a fellow just south of Calgary who does all of mine and if you are in eastern Canada then I'm sure there are options. Cliff (on this board - I forget his 'handle' ) and others may chime in with some suggestions for places in Ontario, and if you are in the CVMG you can always post over there as well. The only crankshaft bearing Suzuki doesn't still sell is 09262-30013 but they can usually be bought from Paul Miller in the US or from Reiner in Germany if you need one.

I do my own crankshafts!! (It helps that I have a 100 ton press at work!!) The GT550 crankshafts are easier to do than the GT750!! The GT750 connecting rod pins move when you press the assembly together! I've had to press the pin into the web and then tack weld it to keep it from moving, then press on the other web! The fun part is truing it and adjusting the run out, but that's another story!! It just takes some time, patience and a big hammer!!
Cliff!!

[oldjapanesebikes]

Cliff!!

Oh - now I feel really embarrassed - Cliff's handle is 'Cliff' ! No wonder I couldn't remember it !