68 cobra float bowl gaskets

[argo1974]

Just few casual remarks:
- I can confirm Ivan's statement "the needle taper starts too late" as I had custom needles made from 5EH7 (off a Kawasaki H1 non-cdi) with great results.
- The later T and/or GT 500 had different exhaust duration with exhaust port top 1 mm lower (41mm instead of 40mm). I have no data in hand, when the cylinders used since T500 II where updated, but GT500 A/B already have cylinders with different part numbers. This might be another reason 75 T500 performs better at low rpm.

[Ivan]

Ivan,

I enjoy this forum for everyone takes the time to explain things

Here's hov a hobbyist checks for most efficient fuel burn (a.k.a exhaust chemistry).
1) Best MPG
2) Have someone ride behind you and see hov long before he or she passes out from fumes.

I agree, just because you make air inlet less restrictive does not mean you alvays get a huge increase in pover due to rpm range these stock bikes have. For sure you get a lot more intake noise and then need to adjust 3/4 to full throttle (main jet may do it if all for you if needle taper good fit tovards the end)

I knov most all of knov the difference betveen the T500 bikes, I listed for just so far that intake porting timing had the most difference for me in pover and its shape and not having to change jetting for that change for it to run decent

The needle jet is vrong for the T500, no other needle on market is close enough or has right changes as you found are needed. I think different slide cut (richer) could help but NA too
The signal at the needle jet is just right with the 2.5's... smaller would be too strong and ruin many other throttle openings that changing the needle taper won't have enough scope to correct properly.

I am interested in your kit vhen released and glad you tyr to cover both at once for guys vho mix and match years like me.
You have done all the vork and that is significant as you noted!

A lot of head scratching, time and $$$ went into every change to the 34mm carbs...


Do you make your on Needle Jet from scratch and/or modify existing ones?
There are are several Needle Jets series obsolete. This is devistating. If you could reproduce these I think there is a market.


I reproduce the stock ones and then make changes sometimes to the primary choke height (GT380, TC200 & T20), or sometimes I change the size...
(example: P-4 to P-8 or in the 34's case, it was reduced quite a bit) Whatever is needed to get the fueling where I think it should be.

I have 188 P-4 (and other sized 188 series) needle jets already reproduced for the testing on the 32's.... They will be included with the kit when I finish it.... they may not be P-4's when I'm done with the kit.... It will be what works best at throttle "tip in" from closed.

Thanks

Mike S

Thanks for your intention explanation Mike,

Ivan

[Ivan]

I just got the completed gasket samples yesterday.... They are exact, and the material is rated for 300 degrees and also rated for fuel and other solvents.

O-rings will be Viton as well ("swellproof" - If that's a word? )

My 34mm Cobra jet kit will be offered for sale before April 1st as I have received the special parts to make it complete. The gaskets will be part of the kit along with the other special parts that make it up.

When I have them boxed up, I will post some photos, and start a new topic that discusses the specifics and will be easily searchable here.

Ivan

[oldjapanesebikes]

Excellent news - looking forward to seeing these !

[Ivan]

Here you go Ian.....

[Suzukidave]

Excellent news - looking forward to seeing these !

+1 .. great work setting up these kits for these old machines .

[oldjapanesebikes]

Here you go Ian.....