CB/CL/CJ360 Big Bore Kit - NOS GS850 Pistons/Rings/Circlips

[NA3S]

I've two sets of standard bore (69mm) NOS Suzuki GS850 pistons used to big bore CB/CL/CJ360s from their stock 356cc to 378cc.

This mod was originally developed by 'CrazyPJ' and has been well documented in various threads.

They are a direct bolt on, merely overbore your cylinders 2mm and these drop right in.

These pistons and rings have gotten very difficult to find.

CB/CL/CJ 360 stroke of 50.6mm x 69mm GS850 pistons x 2 cylinders = 378 cc, equating to a 9.5% increase in displacement in addition to the GS850 pistons being much lighter than the stock 360 pistons.

1st set includes 2x standard bore (69mm) NOS Suzuki GS850 pistons, 2x std bore NOS Suzuki GS850 piston rings, & 4x NOS Suzuki circlips - SOLD

2nd set includes 2x standard bore (69mm) NOS Suzuki GS850 pistons & 4x NOS Suzuki circlips - SOLD

 

[crazypj]

WOW, Suzuki 'ran out of stock with those pistons at least 6~7 yrs ago.
The only way to get them is dealer NOS
That's actually a pretty realistic price, genuine brand new were $108~ just for single piston 8~9 yrs ago when I last priced them, rings, clips, etc are extra
One thing you probably didn't know, the 2mm over piston makes intake port work better (it's too big for stock motor, actually sized for a 400)
Open exhaust port a bit for much better performance

 

[NA3S]

BUMP BUMP

 

[taggat]

Thanks for the info, ill be stripping down a 79 gs850 now.

 

[crazypj]

Seeing how easy the 378cc conversion is I'm surprised no one has bought these yet.
The 378 runs much better than anyone thinks it should (including me and I 'invented' it ;D )
120mph 'CB360' surprises the hell out of anyone (including rider 8) )
Guess financial recovery isn't as good as media and government want's us to think it is?

 

[thrillseeker]

Pm sent


Sent from my iPhone using Tapatalk

 

[NA3S]

Still available

 

[crazypj]

That's crazy, I thought they would have gone ages ago
If I had any money I would take the lot but as wife is now also unemployed I may not even have an internet connection in a few weeks

 

[ridesolo]

That's crazy, I thought they would have gone ages ago
If I had any money I would take the lot but as wife is now also unemployed I may not even have an internet connection in a few weeks

I hear you! I have a line on a good 360 cylinder for pretty cheap, but I am not sure I can spend this much $$ for the rest of the parts.

 

[NA3S]

One set of GS850 pistons left... $250 shipped in the lower 48

 

[crazypj]

I don't even get commission ;D
Someone buy them, it really is worth the expense of the conversion to have a 360 that pisses off bigger bikes 8)
Do a search for people (other than me) who have already done the 'kit'

 

[NA3S]

It astounds me as well PJ, I wish I could've found this set up when I was building my last 360.

If anyone is interested, I may have a line on another set of NOS rings to go with these pistons, PM me if you're looking for a full set.

 

[Chronic]

Great waited untill i got my motor back together

 

[NA3S]

They've been posted since the beginning of June.. Easy to bore a spare cylinder and swap, few hours at most, let me know

 

[Chronic]

price of shipping to Australia and the drop of our dollar really makes it hard to buy

 

[redwillissuperman]

What's the compression ratio afterwards? Quench area? Piston to valve clearance?

 

[NA3S]

Not sure of the #s off the top of my head, they have been covered in depth in several threads on this forum as well as others.

I plastigauged the motor I built and had more than sufficient valve clearance, the quench area is pretty comparable to stock pistons, valve pockets line up perfectly and dont require modification.

I know PJ decked a few of his heads to up the compression a point or two, I didn't bother and was fortunate to have a square and unwarped head; I seem to recall the math working out to about 9.5:1. I ran premium pump gas and well tuned Mikuni VM carbs without issue.

 

[NA3S]

Too bad about your weak dollar, isn't your riding season just starting?

 

[crazypj]

What's the compression ratio afterwards? Quench area? Piston to valve clearance?

Who cares? It works, still runs fine on 87~93 pump gas ;D

 

[redwillissuperman]

Would love to increase compression. Read that you can shave the bottom of the cylinders 0.025inches to get up to 10.5:1.

Oh, sorry, just saw they were sold.