I'm in the twin club….

[tkent02]

OK, turns out 70 ft. pounds is correct, took it apart, put it back together, torqued it to 70 and the gear turns, one way and not the other, a slight amount of side to side play, WTF?

Oh well, on to the next piece of the puzzle.

[pete]

70 is way too much Tom! Just replied to your PM with the spec's from the factory manual... 43.5 - 50.5 lb-ft is the correct spec...

I used some blue loctite on mine as well just to be sure it wasn't coming out...

[tkent02]

70 is way too much Tom! Just replied to your PM with the spec's from the factory manual... 43.5 - 50.5 lb-ft is the correct spec...

I used some blue loctite on mine as well just to be sure it wasn't coming out...

Well, crap. I found the same spec in the Clymer's from Cliff's site as the Suzuki Service manual for the GSX400E, the eight valve twin. 90 - 100 NM, which is 66 - 73 ft. pounds, so I went with 70. Didn't see your information until later. What I don't have is a listing that shows the part number of that bolt on the GSX 400E. It may be a stronger bolt. I think as long as it's on there and the starter gear is working as it should this time I should leave it, unless you think the bolt may break off later due to heat cycles or something? I could loosen it and retorque to 43.5 - 50.5, could even replace the bolt if it may have been damaged… it's been torqued to 70 twice now.
Have to order some parts anyway, gaskets and such.

Now I've looked at the Suzuki manual for the 300 and 550 which both use the same bolt, their spec is 43.5 - 50.5.

This bolt has a 7 on it, that's a grade 10.9 bolt, isn't it? If it is it should be fine at 70, shouldn't it?

Damned Clymer's sucks.

[pete]

Tom my paranoia with something hanging off the end of the crank says replace the bolt and torque it correctly... may be an overreaction but that's what I'd do...

I'm pretty sure the GSX400 uses a different stator and rotor, so there's probably a reason it's a higher torque on those is my guess.

I'm not sure on bolt grades, but what I do know is after stripping one thread due to the Haynes listing an incorrect torque, and almost stripping another, then finding other mistakes in the Clymer, I will only ever refer to my factory manual for torque spec's.

What I should do when I get a chance is get a good quality photo of the torque spec pages (there's only two) and get BassCliff to pop them up on his site, then there can be no mistakes... I can do the same with the harness and cable routing pages too.

[tkent02]

Tom my paranoia with something hanging off the end of the crank says replace the bolt and torque it correctly... may be an overreaction but that's what I'd do...

I'm pretty sure the GSX400 uses a different stator and rotor, so there's probably a reason it's a higher torque on those is my guess.

I'm not sure on bolt grades, but what I do know is after stripping one thread due to the Haynes listing an incorrect torque, and almost stripping another, then finding other mistakes in the Clymer, I will only ever refer to my factory manual for torque spec's.

What I should do when I get a chance is get a good quality photo of the torque spec pages (there's only two) and get BassCliff to pop them up on his site, then there can be no mistakes... I can do the same with the harness and cable routing pages too.

Yeah, I ordered a new bolt. I'd like to find out which grades the Suzuki numbers are, they have similar bolts in stock i a hardware store locally but I don't know if a 10.9 is right. Any higher than that and they have to special order it anyway.

I know I've seen a table of bolt grades vs. the Suzuki numbers, but can't find it anywhere.

Any chance your Suzuki manual is an online version?
If it is I'd sure like a copy.

I'd buy the hard copy if I was fairly certain I was keeping the bike, but I haven't even ridden one yet, it's hard to say.

[pete]

Cool... and yeah I'm sure I've seen a chart somewhere too but a very long time ago...

Unfortunately it's a hard copy only otherwise I'd be happy to shoot it to you. It's a reproduction from eClassic Bike (eBay seller), $US30 plus shipping from memory.

I would highly recommend getting one if she's a keeper...

[tkent02]

After not even looking at this engine for the last nine months, got it up on the table to put the engine together. Clearing some space to work, finding all the parts, got no pistons.
Pretty sure it came with a pair of them, but they are gone now.

Anyone have an extra a set of 450 pistons they don't need?

[pete]

Bugger Tom! Hmmmm over bore and bigger pistons time?

[tkent02]

Probably, I just found a set of pistons in a box from a 1075cc kit for a GS1000. Looks like it will fit. Bore is a little bigger, 18mm pin, I'll bore my cylinder out and use it if the deck heights and such are compatible.

Got any 450 pistons you could measure for me?

[pete]

Sounds good to me!

My only pistons are in use unfortunately... no spares in that department. I have the factory manual but it doesn't go into that much detail with measurements...

[pete]

There is this from the GS Twins Wiki post though:

Bore: ID 71mm
Bore:OD 79mm
Stroke: 56.6mm
18mm Wrist pin
compression: 9.0:1
Base gasket: 0.020 (0.5mm) Gasket
Head Gasket: 0.043" (1.09mm) Fiber

[tkent02]

Found two sets of these 1075 pistons. One is 70mm, unknown manufacturer, the wrist pin and bore has been modified to use a button instead of the wire circlips.

The other is a 73.5mm Wiseco. Both look to be in great shape.

Tempted to use the Wiseco and stick with the wire circlips, what is the advantage of the button style wrist pins?

[Mekanix]

Replied to your PM,

If you want to go big and be sure it works I have a set of pistons that are wiseco high comp and big bore That I'll sell. Mainly just to get what I paid out of it.

498CC's VS 450 and from 9.0 to 10.5 I think was the comp difference (unsure)

minimal boring required. From 71mm stock to 74.85mm.

I bought these from Rich (@wera90ex) a few summers ago for my gs500 for higher compression but that didn't work because the 500's head is smaller and squishier than the 450's so I couldn't use them at all.
I also bought new rings for them at the time and I have a set of gr 650 cam's he gave me. Higher lift with less duration. Just to play with.

You could keep all your parts, do some boring and drop these pistons in directly.

Rich Could probably tell you what his setup was for racing using these pistons.



I think maybe the button style meant that you wouldn't loose a circlip at really high RPM's?

If you can stick them on the 450 head and the dome fits entirely in the heads combustion chamber without hitting the sides and the squish bands around the side should be the only things touching the head, it should be good to use one of those sets, Just have to see if the valve recesses are deep enough.

[Mekanix]

Post # 4 by @bwanna

[tkent02]

OK, going big....
Just bought a set of 500 cylinders/pistons.