Rebuilding the GP100

[Slingshot]

I've got a few questions about putting my GP100 motor back together, the first one is rhetorical.

- Why did I think it was a good idea to fix something that wasn't broken.
- Should I put some locking compound on the outside of the bearings to keep them from spinning in the housing...or is this not necessary?
- I've got a new gasket set..the question is should I use a gasket between the crank case halves? And should I use goopy stuff to make the seal better?

I'm sure I'll have more questions, but answers to the above would be handy to start with.

Cheers John

[TZ350]

- Should I put some locking compound on the outside of the bearings to keep them from spinning in the housing...or is this not necessary?

- I've got a new gasket set..the question is should I use a gasket between the crank case halves? And should I use goopy stuff to make the seal better?


Is this a Suzuki GP100. if so. Things the workshop manual does not tell you:-

Team ESE have not used locking compound on the outside of their main bearings and had no problems with them spinning in the cases.

A GP100/125 does not use a gasket between the case halves. Some Suzuki singles do some don't. Use Yamaha bond or something similar to seal the case halves. We have found that they can leak if you use that red Locktight Master Gasket Goo.

When you put the rotary valve back put the shiny polished side to the outside and a bit of sealant on the rotary valve driving dog where it buts up against the main brg. So the motor can't suck out the gear box oil.

One side of the driving dog has a smooth ground surface for the oil seal so get it the right way around when you put it on.

You can only put the mainshaft key in after the rotary valve driving dog has been pushed on the crank and all the way up to the main brg.

There is a little notch on the rotary valve that lines up with the keyway. You can put the rotary valve back two ways, one side will be a little polished from rubbing on the outer cover. Put it back with the polished side out ("out" means facing you).

Remember "Notch", "Keyway" and the fact that the "Inlet" opens way before TDC (top dead center) and closes early ATDC (after top dead center) and you can't go wrong.

There are seven little pins, six of them hold the clutch springs the seventh goes in the plastic gear and shaft that drives the oil pump and tacho. People often forget the oil pump drive pin and then it all blows up a few miles later. A sure sign that this pin is missing is that the Tacho drive does not work.

Inside the gearbox there is a small washer that goes on the small end of the output shaft.

And a very thin "O" ring that goes over the output shaft on the outside at the sprocket end. This "O"ring seals the output brg and the small sleeve behind the sprocket so gearbox oil does not leak from there.

Hope this helps.
.

[quallman1234]

I wouldn't bother with locking compound with the bearings. As this is your first rebuild you might end up taking it apart again, plus its unlikely that it will spin in the cases.

Does the gasket set come with a gasket for the case halves?
If so then yes, you should use it. If not just use some goo stuff, make sure its high temp.

[F5 Dave]

Suzukis don't usually run center gasket. That grey goopy sealant is good, the same as Yamabond, name escaping me, something like 3M but not. Bike shop should stock.

I've had to use bearing seal, but only once on a worn set of cases where you could see the bearing turning.

[Skunk]

Suzukis don't usually run center gasket. That grey goopy sealant is good, the same as Yamabond, name escaping me, something like 3M but not. Bike shop should stock.
Threebond. Two types - one for 'normal' cases and one for 'damaged'. I've always used the 'normal' one. Called something like Threebond 2-11 I think.

[F5 Dave]

Ahh, thank you 3 Bond. :done:

[Slingshot]

Good info, thanks.

Next question, I was going to reassemble the motor without the kick-start assemble. Is this as simple as not sticking those bits in and plugging the case where the shaft comes out?

[Skunk]

Was for me.

Ferkin hard to start mine now though... I think it misses the parts and is getting back at me for it.

[F5 Dave]

Yup, hook the parts out & epoxy a 2c piece (or whatever currency fits in there) in place after scrupulously cleaning it, maybe followed up with some Kneed-it (try borrowing Skunks, he seems to give it away for free).

Then don't be a pussy & push it.

[bucketracer]

.

ThreeBond 1215 and it comes in a white box with red and white logo and some black Japanese writing.

Also has "Liquid Gasket. Gray Solventless Silicone Sag Type." on one side.

So there we have it, just the Bees Knee's.
.

[Skunk]

Yup, hook the parts out & epoxy a 2c piece (or whatever currency fits in there) in place after scrupulously cleaning it, maybe followed up with some Kneed-it (try borrowing Skunks, he seems to give it away for free).

Then don't be a pussy & push it.
Don't be a cheap arse.
Get a frost plug the right size and save the coin and gasket goo/epoxy/knead-it etc.

You can't get any knead-it from me. I gave it all away.

[Kendog]

You can't get any knead-it from me. I gave it all away.

Do you 'knead-it' back? :shifty:

[Skunk]

Do you 'knead-it' back? :shifty:
That was pathetic. Try again.

[Slingshot]

Don't be a cheap arse.
Get a frost plug the right size and save the coin and gasket goo/epoxy/knead-it etc.

You can't get any knead-it from me. I gave it all away.

I was planning on having a thread put in the case and plugging it. What's a frost plug?

[Skunk]

A dished plug that is hammered into the hole. They are used in (older) cast iron engine blocks on cars to fill the casting holes needed to form the water jacket. They are availble from Repco, Tonys Auto Centre (Tory St) and the like.

[F5 Dave]

Sounds heavy.

[Skunk]

About the same as a coin, goo and knead-it.

[Slingshot]

A dished plug that is hammered into the hole. They are used in (older) cast iron engine blocks on cars to fill the casting holes needed to form the water jacket. They are availble from Repco, Tonys Auto Centre (Tory St) and the like.

I know what you mean, but I suspect that hammering one of those into the thin alloy casing could create a few issues :)

[Skunk]

Nope, do it all the time. Measure the kickstart hole carefully and buy the plug marked with that size. Put a socket in it and hit it. Done.

[Trudes]

"How to measure a Butt Plug" by Skunk.

[Kendog]

That was pathetic. Try again.
I got nothing........


"How to measure a Butt Plug" by Skunk.
But that is gold :msn-wink:

[koba]

My old KLR had a piece of plastic made to the shape and carefully placed behind the seal that normally sits in there. I bet it was worth a good half gram.

I took part of the ratchet off the RG when I broke the return spring but it is all back in there now as I got sick of pushing very quickly.

[Slingshot]

Next question:

How important is the main bearing retaining plate? I can't find one in my box of bits but the Haynes manual is telling me to stick one in.

Can I do without it?

This is what I'm talking about. (http://www.facebook.com/photo.php?pid=586512&l=ebc305a2ea&id=1131683622)

[F5 Dave]

Main bearing? You mean clutch shaft bearing. I had a crank main bearing move when the plate undid & it scraped on something. I'd find one & apply loctite to the screws.

[TZ350]

Next question:

How important is the main bearing retaining plate? I can't find one in my box of bits but the Haynes manual is telling me to stick one in.

Can I do without it?

This is what I'm talking about. (http://www.facebook.com/photo.php?pid=586512&l=ebc305a2ea&id=1131683622)

You defiantly need that plate, PM me if you cant find yours and Ill send you a spare. Also there should be a washer on the small end of the output shaft where the index finger of your left hand is in the picture.
.

[Slingshot]

Main bearing? You mean clutch shaft bearing. I had a crank main bearing move when the plate undid & it scraped on something. I'd find one & apply loctite to the screws.

Actually...I meant mainshaft bearing (that's how the Haynes manual describes it). Clutch shaft is even more descriptive :)



You defiantly need that plate, PM me if you cant find yours and Ill send you a spare. Also there should be a washer on the small end of the output shaft where the index finger of your left hand is in the picture.
.
I haven't got a hope in hell of finding it...PM will be sent shortly :)

PS...that's not my left hand in the picture, it's the finger of Mr Haynes...and I have put a washer on that shaft, hopefully it's the right washer...it seems to fit reasonably well. :confused:

[holloshaw]

weres the best place to get a Haynes GP100 manual? an ebook would be perfect

[Slingshot]

weres the best place to get a Haynes GP100 manual? an ebook would be perfect

I got mine off Trademe. There are lots on eBay.co.uk.

[Slingshot]

I'm in business again!

A parcel turned up this morning with a replacement plate, a thrust washer and a selector fork!

TZ350...You're a legend!

[Slingshot]

I've just joined the two crank case halves. They seemed to go together nicely, but it's pretty much impossible to turn either the output shaft or the clutch shaft by hand...I expected that these would turn freely.

Have I fucked up?

[Henk]

They should turn freely. It's not in gear is it? Should still turn OK even if it is I think.

[Slingshot]

They should turn freely. It's not in gear is it? Should still turn OK even if it is I think.

Tried turning in gear and in neutral, doesn't seem to make any difference.

[Henk]

Do the shafts turn at all? Been a while since I've had anything that far apart but from memory you should be able to turn either shaft and with some effort both of them with the box in gear.

[Skunk]

With my TF I had to hit it with a soft face hammer on the end of the shaft. Turned freely after that. Next time I had to the same thing.
Funny cos with the AX I never needed to.

[Trudes]

The MB did the same thing... I think Sully may have used a similar method to Skunk's.....(Give it the bash)

[bucketracer]

With my GP100 I had the same problem, To find what was wrong I assembled the cases with one shaft at a time to find which one was binding. Each shaft should have some end float, 0.25-0.5mm. Turned out I hadn't seated one of the bearings properly.

Other problems I have heard of was a selector draging on the bottom of the grove in the gear (could happen with a mix and match gearbox from different years I suppose) and the small washer on the end of the output shaft was to thick.

[Sketchy_Racer]

Give the shafts a medium whack on the end of them to seat the bearings in. When you bolt the cases together the interference fit of the bearings mean that there is still a large amount of side load on the bearing, causing the stick that you are getting. They just need a whack to push the bearings fully into their seats and you'll be away laughing.

[Slingshot]

Good advice :)

A couple of gentle taps and she's turning nice and freely :)

[F5 Dave]

Yeah they usually make a nice creak/crack noise.

[speedpro]

That'll be your collarbone you are listening to.

[Slingshot]

I'm now putting the rotary valve assembly back on so I need to decide if I'm going to open up the disk...problem is that you only get one shot at these things.

I'm thinking I might go half way between the GP100 & GP125 opening...surely that would be OK.

[quallman1234]

I've got a few questions about putting my GP100 motor back together, the first one is rhetorical.

- Why did I think it was a good idea to fix something that wasn't broken.
- Should I put some locking compound on the outside of the bearings to keep them from spinning in the housing...or is this not necessary?
- I've got a new gasket set..the question is should I use a gasket between the crank case halves? And should I use goopy stuff to make the seal better?

I'm sure I'll have more questions, but answers to the above would be handy to start with.

Cheers John

10 Characters.

But a little bit of a grind can't hurt if you know what your doing.

[Skunk]

Have a look at the Two Smoke turning thread and the ESE Team thread. One of them has details... Search might help.

[Slingshot]

A year on and I've finally got my shit together.

Valve assembly, clutch and right side cover...done.

Flywheel and stuff to be sorted tomorrow night :)


Thanks for the motivation Skunk.

[Trudes]

Yahhhhhh! :woohoo:

[Skunk]

A year on and I've finally got my shit together.

Get the spacer sizes to me eh?

[Slingshot]

Get the spacer sizes to me eh?

Ummm...no, not yet.

I did re-measure though and then compared with my original measurements - which were different :(

I have found an axle that looks like it'll suit the front - will need to be turned down a little and a new thread cut - but it's a start.

Anyway - I'll measure once more and will let you know what's needed ;)