Carb setup spreadsheet - Ivan carb kit

[Windy]

Last year i decided the surging on the H2a was too much to bare so went for an ivan carb kit.

My first impressions with the ivans kit with recommended settings are too rich (std bike with stock filter no trumpet). Ive now gone to std pilot (one size below ivans recommendations , needles dropped one notch from the recommended centre groove and 107.5 mains. It runs acceptably but lacks the top end umph it used to have. Next plan is to drop the mains one more size with needle raised back to centre groove. It used to be a tad lean at top end (slight pinking when ragging it) but i never holed a piston. I will keep dropping jet size until i reach that point and go back one!

Low throttle surging is a lot better but there still feels a slight hesitation from zero throttle to 1/4 (still a bit rich).I hardly need any choke now hence i suspect rich at idle but this may be the compromise for stopping lean surging at low throttle!

I also notice at totally closed throttle, coasting down a hill the engine (or is it one cylinder?) surges slightly, approx once per second (like the "ring ding ding" smaller engines do). Never had this before so its a new one on me.

Ive followed the mraxl carb setup many times and im still working on with a steady progression to perfect it but welcome any suggestions.

I was talking to Hucklow Tom, he seems to remember a table/ spreadsheet with many ivan carb kit setups. The only table i can find is https://docs.google.com/spreadsheet/ccc ... hUXc#gid=0

This only has a couple of ivan setups. Is there another spreadsheet out there?

Cheers mducks
Windy

[downpipe3]

might be yer crank seals on the way out Dave

[Windy]

I doubt its the crank seals. The crank was done by Chris Ritchie, one of the last he did so its only a few years old (bless him).

Cheers Dave

[Hucklow Tom]

Err, Sorry, Dave. I think that is the one that I had in mind .

Old age and failing memory to blame methinks.

[JohnB]

Maybe it just feels like it's lost some top end "oomph" as its now smoother in the midrange and just not so brutal.
Can't see raising the needle again is going to do much for the top end,isn't the needle already out of the main jet on full throttle?

[downpipe3]

I doubt its the crank seals. The crank was done by Chris Ritchie, one of the last he did so its only a few years old (bless him).

Cheers Dave

ok that's good