Engine rebuilding

Cyanide

Cyanide

Cyanide

Soldato
Joined
5 Mar 2006
Posts
3,975
Location
Nottingham
I'm currently in the process of re-building the engine on my bike. I know you guys mostly specialize in car mechanicals, but I think this'll be the same answer for cars and bikes.

The generator on my collapsed a few months ago (the resin disintegrated) and having that much mass spinning unevenly has caused a couple of the pistons to crack. Obviously the generator and cracked pistons need replacing, but...

1) Will all the pistons need changing to have a matching set or just the dead ones?
2) Can I re-use the old piston rings
3) Will there be anything else (bearings etc) that should be replaced when doing this?

Response is appreciated, you'll get a decent "rebuilt from scratch" project thread if I can sort out the engine :D
 
Have the cracked pistons marked the bores at all?. If not, i'd have the barrels honed and new rings fitted to all cylinders...if they have, i'd be tempted to do the lot with a rebore and new pistons/rings.
:)
P.S. What bikes it?.
 
jon.bda said:
Have the cracked pistons marked the bores at all?. If not, i'd have the barrels honed and new rings fitted to all cylinders...if they have, i'd be tempted to do the lot with a rebore and new pistons/rings.
:)
P.S. What bikes it?.
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The barrels are fine, it's just a hairline crack at the thin part of the base of the pistons (where the rods join). Reckon one of the bore cleaning/polishing kits from Halfrauds would do the trick?

It's a 1991 Suzuki GSF400 Bandit. Some would say it's not worth saving, but it's my baby! :D
 
Sounds like std size (hasn't been rebored already?) pistons and rings with a honing should be okay then?. If your unsure of the engines history i'd be tempted to get it done professionally and get the bores measured for size as well. And i've not seen the Halfrauds kits but honing tools ain't expensive...
:)
P.S. Love the Bandit, want one myself!.
 
jon.bda said:
Sounds like std size (hasn't been rebored already?) pistons and rings with a honing should be okay then?. If your unsure of the engines history i'd be tempted to get it done professionally and get the bores measured for size as well. And i've not seen the Halfrauds kits but honing tools ain't expensive...
:)
P.S. Love the Bandit, want one myself!.
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The history's sound, it's only done something like 18k and I've got a FSH for it. I'm in the process of re-painting the bike at the moment as I got bored with the standard red so I might have to wait until the summer if it's going to need new rings etc as well. The only place I've found that sells new stuff for them at the moment is www.bikebandit.com and it comes to around $400 plus shipping :(
 
Andri said:
they seem very rare bikes, are parts fairly hard to source?
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not from the states and there's a fair few parts on ebay, I'm just in 2 minds about buying used engine parts. Plus the GK75 engine is completely interchangeable with the GSXR400, hence me having silly amounts of power when it actually works :D
 
no chance of finding a re-con GSXR motor for it then?

my bro seems obsessed about putting a GSXR750 into his 600bandit :p
 
Andri said:
no chance of finding a re-con GSXR motor for it then?

my bro seems obsessed about putting a GSXR750 into his 600bandit :p
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They're too expensive and it already has GSXR cams, carbs and gearbox ;)

I was tempted to just get a GSXR600/750 lump and drop it in but I don't think I've got the time to custom fit it to the frame :(
 
As long as the pistons are the same articles as the existing ones you can just replace the offending items. I would buy new piston rings and new bearings throughout. You might aswell recon it while it is in pieces instead of just fixing it.
Might be worth replacing all 4 pistons actually, because if 2 have cracked no doubt the other two have had a hard time aswell.
 
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