Suzuki 2 Strokes

Is it possible to swap in a 6 speed tranny from the T250 or T350 into a T500?

Thanks, Jesse

Bump: Not finding anything on it so I guess it's not possible? anybody ever looked into it?

It has been talked about on the forum - been a while though. The T500 gear box is a completely different design with just a single shaft holding all the shift forks. The other two you mention are dual shifter shafts with the forks split two to each shaft. Nothing is impossible given unlimited money and time, so I suppose a better question would be 'why ?'.

Just helped my friend swap in a 6 speed to his fzr1000 and he really likes it.. I don't know if it would even be practical on the T500 but thought I'd ask and see.. Thanks for the reply! Another question I have is I'm running without air filters on my T500 right now, and it seems to be running very strong all the way up to redline, wondering if re-jetting is required when running pod filters?

jleeb wrote:wondering if re-jetting is required when running pod filters?

The short answer would be 'yes', unless you like replacing pistons Lots of info on this site - just do some searches.

Properly oiled pods will richen it up some but not much. Stock jets should be fine. You may have to tweek your mixture screws. Worse case would be dropping your jet needles a notch.

I have the needles raised one notch right now as it seemed to be running rich.. Any suggestions on what kind of filters to get?

Yeah....
If you HAVE to run pods, then spend the bucks and get genuine K & N's.
Those Taiwanese knockoffs are a joke when it comes to actual filtration qualities.

Don't have an air box, and not a lot of cash, so pods are the way I'm going.. Would UNI's be OK?

Yep, I have uni pods on mine and they work fine. Besides, I read somewhere that having the kind with a metal backing plate can mess with the back presure which I guess could impact performance. Not sure how true this is.

It's true, but how much of an impact it has is not well documented.

The issue is blowback aka Flow Reversion. It happens on all two strokes and is worse on piston ported motors with long intake duration.

As the piston descends, some of the intake gas is reversed and flows back out of the crab and is then sucked back in again so it picks up fuel in each direction. So it gets to be very rich at low speeds. That's normal but with a flat plate the whole wave is reflected back as a negative wave where some of the wave energy is normally lost in the air box.

Tests on RD Yamahas showed it to be a real PIA that made it almost impossible to get them to run well at lower speeds.

Regarding the six speed question - the factory TR500s eventually had a six speed box so it is possible. What changes the factory made to get it all in there, I don't know as I've never seen the guts of one. I can tell you the shift drum on the T250/350 is not the right size to fit into the T500 cases plus there's the whole two shift fork shafts on the 250/350 versus one on the T500. To me it doesn't look like there's enough room to add a second shift shaft in the 500 crankcase so you'd be stuck machining a new shift drum.

Someone pointed out the GS500 six speed gearbox which only uses one shift shaft. That might be a good candidate to swap although you still may get into issues with the input and output shafts on the trans gears.

Nova racing transmissions in England can sell you a close ratio 5 speed trans for the T500 but they go for just over $1,000 at today's exchange rate. Pedro (on this board) and Nova both offer straight cut primary gears for the T500 but with Pedro you can get the gear riveted to your clutch basket. Nova just supplies the parts.

Jim

Thanks, everyone for all the answers!

Not sure if I'll have money for a whole lot of parts right now, but header gaskets and air filters are def first on the list.. been using aluminum foil for gaskets and it's worked pretty good but it has to be replaced quite often.


I wasn't sure about the 6 speed, it just feels like I need another gear when I get on the long straights..

Why don't you "only" change the ratios?
http://www.novaracing.co.uk/suzuki-gt500.htm" onclick="window.open(this.href);return false;

Philippe

Another question if I have gas leaking out the back of the carb, does this mean my petcock has a vacuum leak?

Jesse