T305 Ex port raised 2mm to 30.5mm not good

[Vintageman]

Tz

Yes perfect. Thanks.

I don't have jemco's but chrome Bassani's 3 into 3 ... keep center stand with these.
Jemco's look like they may have a little more volume for example, but the Bassani did add a boost over stock pipes and were a good deal.

When I do this mod i'll reply give my butt dyno results I have everything i need just time.

Mike S

[ja-moo]

Another WOW! The timing on these guys is so ridiculously mild...... I am learning a lot about these Suki's. Glad I port the Kawi's.......

[Vintageman]

0.020" off head helps for sure. Still regrets with why around 5000-6000 RPM wont hold a grade like it use to....

Then, the other day one cylinder stopped firing. Shorted condensor . Looks like center had been loose in body for a while then evetually shorted to body . Changed that. voila it runs perfect . the midrange holding torque is just fine!

I have to concluded that the condensor must have been on its way out and a freekin coindcidence. This is all I did (24 degree timing, but I was close to that al rady too).

Also a "tuned" engine is more senstive and demands things be spot one.

Things are seating in well it seams, bike is much faster, and when I shift at high rpms it will slip clucth more so cold

Is there a stiffer spring aftermarket?

[Suzukidave]

Check the bind height on the springs , maybe you could slip a washer in ?

[Vintageman]

Suzukidave, was thinking that too.

I just found out something interesting. The bottom end on this bike (actually whole bike is) a 1974 GT250 with a T305 Top, carbs, air box, oil pump, handle bar dampners, etc.

The 1974 Gt250 EOM spring # 09440-19005 and looks like only a couple bikes used it T250 and Gt250 up to M. Also Not availble

But a true T350 and a bunch other bikes (GS550E, GS650, GT380, GT250 A/B etc.) use 09440-19004.

Wonder if stiffer?

Can find Barnett's for the suz 09440-19004: its Part# 501-45-06050. This suz part is avaible too. Usually Barnetts a little stiffer (too stiff sucks on hand)

[Vintageman]

I would like to add, that I needed to lean the jetting to my surprise if anyone wants to copy this mod. The main from 112.5 to 107.5 and Clip Leaner one notch still little rich but that to me helps keep WOT cool, Also put a T305 air box versus T350

This helped the issue where the bike would not take mid to full throttle if RPMs out of power band. The proper advance is the most important for good midrange. Overall raising the Ex as noted made this bike a screaming top end machine. The tradeoff was loss of midrange. Funny low rpms lugged OK

I put around a couple thousand miles on with this mod and a blast, never could ride her easy, always existing, the loss of midrange made it not practical to ride on the interstate anymore (hilly where I am ) unless above 7000. Whereas before it would lug 6000 rpm OK.

Couple nights ago I was beaten on it, reved high ~9500 RPM and the BE cage started to fail. I turned it off ASAP and it did not ruin the cylinder and only a few pit marks top piston and head dome.

This is the third GT250/T350/T250 crank that has failed this way they don’t like to rev much above 8000 rpm. Week point seems to be BE.

I plan to put my stock T350 jugs . I miss the midrange grunt