1968 Cobra Carb Tuning Kit

[Ivan]

Well Guys,

It's finally finished.
These 34 mm carbs are finally working they way that they should.

Every issue that they had has been addressed....

Text below is taken directly form my website
http://www.ivansperformanceproducts.com/t500.htm

Kit photos:
http://www.ivansperformanceproducts.com/cobrakit.htm

Float bowl Gaskets (new reproduction - Exact Replicas)
Float bowl O-rings (new reproduction made from Viton - these should last indefinitely)

New Genuine Mikuni needle and seat assemblies w/gaskets
(Spring loaded needle type) These won't vibrate themselves into severe stepped wear.

Custom 5 clip postion, 4 angle needles for a much more precise fuel control.
Made from stainless steel w/mirror polished finish for long life and virtually no wear

Brand new custom size needle jets

3 sizes of Genuine Mikuni pilot jets.

7 sizes of Genuine Mikuni OEM Hex style main jets.

New float bowl vents -
I have changed the vent design to external
The internal vent design was just a really bad design and caused a lot more problems than it actually solved.

All special tools included

Step by step photo instructions for easy installation (if you are mechanically inclined)

Setup instructions with suggested settings.

Kit also includes a list of problem areas associated with this bike and how to minimize these problems during the tuning process.

I have re-designed the entire function/fuel slope of every circuit in these 34 mm carbs to get them to do what they should have done from the beginning.

No more surging, pinging and bucking at small throttle openings

No more bucking at closed throttle decel.

No more bad hesitation and bogging at low rpms.

Better fuel mileage.

Runs cooler.

Bike will accept full throttle from 3000 rpm in any gear.

Dramatically less vibration throughout the entire rpm range.

Dramatically better throttle response at all throttle positions !!

A real pleasure to ride !!

Questions?
Please ask,
I made this kit available for all the 1968 T500 owners that want their bike to run as good as it looks.



Ivan

[oldjapanesebikes]

Looks great Ivan - as discussed I'll order a kit once I get back from holidays ! For clarity (and looking at the photos I see this), this does a pair of carburettors so one kit per bike right ?

Have you posted this elsewhere ? If not I can repost it on two other T500 boards I'm also on.

[Ivan]

I have not posted elswhere..
Yes it is for both carbs.

Thanks Ian,

Ivan

[Knut]

Hi Ivan,
Been looking on your site for a kit for the early Kawasaki H1 (69-71) and the Suzuki GT550. Do you plan to make kits for those?

[Ivan]

I'm re-doing the H1 kit... Based on the knowledge gained on the Cobra kit, I think I can totally fix the weak low rpm problems and improve the whole rpm range even more.
It will work in all the H1's as long as 2.0 slides are used.
Should be ready sometime in May.

I don't own a GT550, so it's not in the near future.


Thanks,

Ivan

[Knut]

Will it be tailored for the early H1? It has a completely different carb setup and than the later models, and air intake is different too.
Cylinder porting is also slightly different on the early bikes. I have the very early bridgeport ('69 only) cylinders on mine, it's not much power at low rpm.

[Ivan]

The porting changes on the H1 throughout the years isn't anything major, in fact it's very minor (in terms of fueling requirements)

The early model carbs had different height needle jet hoods (primary choke)... this in turn requires different needle profiles. They were experimenting with different slide cutaways and needle heights until they got it right with the 2.0's. The early ones carbureted the worst at small throttle openings.

The intake system on the early H1 is less restrictive than the later ones (excluding the KH500), but not by a whole lot... changes here are remedied with only a main jet change (once my kit is sorted)

When you change to pod filters, the whole intake system is "out the window" and all of my kits work with any intake system... stock, silencer removed, or pod filters.

The worst problem that these bikes have with internally vented carbs is the bogging at low rpms and a slight delay in fuel delivery on full throttle shifts... this causes a larger main jet to be needed.

This delay in fueling on a 2 stroke causes the bike to ping momentarily when shifting at full throttle/high rpm from a momentarily lean mixture... this is because the fuel has a much harder time being sucked out of the bowl from less pressure..... a real crap design.

This 68 cobra runs fantastic at all throttle positions compared to what it was.

So will the H1 when I'm finished... (hopefully sometime in May this year)


Ivan

[Knut]

Looking forward to the H1 kit