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tbo
11-11-2011, 12:19 AM
i have an 85' tri-z 250 with a stock carb. i also have the stock carb of of my 85 250r. would it be worth it for me to put my r carb on my z? the z is mostly stock, dg silencer is about all.

bkm
11-11-2011, 12:47 AM
Upgrade it to a newer PWK carb and never look back. I personally wouldn't mess with the old round slide 250r carb. But thats just me.

tbo
11-11-2011, 10:53 AM
i put the 86 carb on my r. i do have a 39 off of a 2002 cr 250 that i was going to put on my r if its not too big, then i could put the 86 carb on the z. what kind of mods would i need on my r for the 39 mm carb?

Mosh
11-11-2011, 10:59 AM
The 85 carb on the Z works perect IMO and is not really worth changing unless it is bad for some reason.

If you are going to put a 39 mill carb on a 250R, you are going to need a host of mods done to it, to make that work correctly.
You will need or want: porting, tighter compression, better reed system, and a good pipe at least. Otherwise if you leave it all stock and run that 39 mil carb, you are going to have a machine that bogs down low, but revs to the moon.

tbo
11-11-2011, 11:07 AM
Well i have the pipe and i was planning on getting some porting and vforce reeds this winter. Can i get away without the tighter compression? Arent the r's maxed out there as far as running pump gas goes?

bkm
11-11-2011, 01:32 PM
Well i have the pipe and i was planning on getting some porting and vforce reeds this winter. Can i get away without the tighter compression? Arent the r's maxed out there as far as running pump gas goes?This is the combo I ran with my '86 250r and it ran great in all ranges of the powerband.

I ran a thin 89 cr250 head gasket to bump up compression, still on 93 octane at 32:1
Lightly ported
.040 Weisco
Boysen Rad valve
Paul Turner Hi-Rev Pipe
Duncan Racing 39mm PWK

I never had a problem with it, but I wouldn't of ran that carb on the stock engine or just a piped engine.

Getting back to your original question, what is wrong with the carb on your Z? I was assuming there was an issue that's why I recommended a PWK. Something around a 36mm for a stock engine. But if nothing is wrong with it leave it alone unless your dead set on changing it.

tbo
11-11-2011, 01:47 PM
The z carb is in working order I just figured the bigger r carb would be a bit of an upgrade. The z carb is already out for jetting purposes.