Mechanical/restoration supervision sought

[terbang]

There is not a lot you can do to the cam shaft diameter apart from replace the cam though they don't wear a lot so should be right. I've got cams here that have done over 100000 K's and they are still within tolerance. Valve springs are worth replacing though and it might be worth you pricing up a set of valve guides as well. I would change the Cam chain and its assorted blocks while its apart as it really is a bitch of a job to do in the case of later rattles and bangs in that area as you have to pull the whole engine apart again. I always fit a new set of intake boots on these old girls as they are generally perished and leaky, though it is hard to spot. Take a close look at top gear pinions as they are the ones that wear the most especially if some slacker has been tardy with his oil level or changes in the past. If you have cam wear so be suspicious of other areas.! The crank is a roller assembly, mains and big ends and they cost a fortune to rebuild so look after that bit. There is a simple runout test you can do and visual inspection on the races there. Don't get too excited about honing the cylinders, just do it very lightly if you need to at all. They keep their oil fairly well except for the cylinder base gasket and the stator cover, that need close attention to cleanliness during assembly. Use the Suzuki gasket on the Stator cover as they have a rubbery compound on certain portions that aftermarket (like Vesrah) don't seem to have. I use that three-bond stuff on the main casings and I've not had any leaks there with clean surfaces. Have a close look at all your threads, remember they are getting up to 1/4 century old now, and helicoil any dodgey looking ones. Most are M6x1.0mm. Nothing worse than assembling a casing to find a damaged thread and have to start again.
And have fun..

[peasea]

Good call on the valve guides; any wear, chuck em. This will require refacing of the valve seats but you might want to look into that anyway. Also the valve faces. Gary at the Cylinder Head Shop in Glenfield could sort that for you, heads are his game and he's good at it. (Of course you could get it ported while you're there, he's got a flow bench........)

If you do need to reface the seats, get a three-angle valve job.

[psyguy]

first thing's first...
many thanks to SURFER for coming over and lending me a hand and some tools, and a few words of advice too


now, i got the engine casings back from vapour blasting
very happy with the result and decided to just leave them as they are (no painting)

started puting things back together - the crankshaft and the gear shafts so far

had a big scare with a misplaced part (one of those bearing locating half-rings went hiding on me). i think my heart stopped for a moment...

still waiting for the new parts from the states. aparently suzuki warehouse didn't have the pistons in stock...


have a bit of a problem taking out the gear shifter oil seal (at least without doing any damage)... i'll post a photo later

cheers everyone

[Storm]

no more nut fuckers, i promise
thanks for the comments peasea

Damn straight, be a man and use a mans tool- the almighty VICE GRIPS!!!!
Guarranteed to fuck ANYTHING- not just nuts.
Really, a set of those and a hammer is all you need for any job
























Seriously, great work so far mate and keep the updates coming- might even inspire a few more projects out there in KB land

[Eurodave]

now, i got the engine casings back from vapour blasting
very happy with the result and decided to just leave them as they are (no painting)

Sorry to rain on your parade but sadly if you dont put either a clearcoat or paint on jap alloy it WILL gradually oxidize turning white & furry in a short time. To help forstall this, seeing that youve already started reassembly ,liberal & frequent applications of WD40 or CRC 556 may help in the short term......I speak from bitter experience!! BTW I also own a '77 GS750 with exactly that problem

[Ixion]

Meh. Stillson, that always does the trick

[psyguy]

Sorry to rain on your parade but sadly if you dont put either a clearcoat or paint on jap alloy it WILL gradually oxidize turning white & furry in a short time. To help forstall this, seeing that youve already started reassembly ,liberal & frequent applications of WD40 or CRC 556 may help in the short term......I speak from bitter experience!! BTW I also own a '77 GS750 with exactly that problem

could you possibly post a photo of what it turns into and after how long?
cos i was told by someone they have left it bare with no problems even after few years ?!

[terbang]

Believe me if you don't put something on it it will dull off and start fizzing. I've got one here that someone had stripped and left, looked great but not for long. . Needs redoing. That is why Suzuki painted them on the first place. Make sure you use a product that can withstand fuel and oil. Thats why I use a 2 pack. The yanks often powdercoat them with good results as well. Pure Aluminium won't corrode but its not that strong either and these jap parts are alloyed for strength which is why they will fizz. Head over to here for some good guff on GSes.

[The Pastor]

what is vapour blasting?

[psyguy]

what is vapour blasting?

A liquid blasting process in which the fine abrasive particles are suspended in water and propelled toward a surface at high speed by air or steam.

[The Pastor]

A liquid blasting process in which the fine abrasive particles are suspended in water and propelled toward a surface at high speed by air or steam.

is it expensive?

[psyguy]

is it expensive?

all the parts you see in the photo above (basically, a complete engine minus the side covers)- $350
the parts were rather dirty (even after a thorough srub with an engine degreaser and a brush) - there's a photo somewhere at the begining of this thread

[Duc]

So who does Vapour Blasting (Auckland area) ?

Does the engine have to be dissassembled to the block and casings only?

[psyguy]

so...
i've done a lot of research on vapour blasting, including corespondence with some motorcycle restoration specialists overseas
the shortest story is that the quality and the appropriatness of vapor blasting for motorcycle engines depends on a couple of factors
1. correct manipulation of the blasting process
2. the engine alloy used

1 - blasting process can be fine-tuned using aggregate/beads of various hardness and size, the water pressure can be adjusted too, and also air can be added to the process. sometimes an after process is used to get an extra smooth surface
2 - different alloys (while all aluminium in essence) respond differently to blasting

these are possibly the reasons for such of a variety of experiences people have with this process. so, some just leave the finish as such, some clear coat it and some paint it - with a variety of paint finishes and/or clear coats. add to this the importance of the appropriate surface preparation and the products used and you get the following: with any of these methods some people report a long lasting finish while others get disapointing long-term results...

So who does Vapour Blasting (Auckland area) ??

Does the engine have to be dissassembled to the block and casings only?

try ph 09 238 3832 (a place in pukekohe i went to) or one other place ph 09 292 2902

the engine has to be completely disassembled as the process uses water and tiny beads that have to be thoroughly washed out afterwards

you can see a finished product at my place if you like

[psyguy]

picky tells you where i'm at in reassembly

after much deliberation and some agony over not being able to forsee what finish should provide a long lasting satisfying result i opted to clear coat the crankcases with a two pot clear that's supposed to be ultra-tough yet flexible, and should also stay brilliant clear (?)
so, the future will tell... (yes, i know, it might yellow, crack, peel off, ...)

all the sidecovers taken for a professional polish
resprayed the exhaust
still waiting for the spare parts from the states