Carb noob pop off question

[mattural.ice]

Earlier this year I picked up a WB1 after a few years of on and off searching. It has a 62t/61x, stock 38s, Factory limited pipe, and Ocean Pro Flame arrestors. I am experiencing a mid range bog/hesitation most noticeable when I get off throttle and quickly back on. The ski starts and idles great, hits hard off idle and pulls good up top. After some research and talking to some local guys I believe my pop off pressure is off. I have some genuine Mikuni rebuild kits in the mail so I’m going to tear into it this weekend.

What should my target be for pop off pressure? Also is there a science behind determining baseline pop off or is it just a trial/error thing that comes with experience in tuning carbs.

 

[blasterdude]

With the Ocean Pro arrestors you are probably going to want to be in the 20's for pop off.

 

[wmazz]

I am experiencing a mid range bog/hesitation most noticeable when I get off throttle and quickly back on.
The ski starts and idles great, hits hard off idle and pulls good up top.

First off, carbs are not designed to respond to snapping the throttle open.
It causes a lean spot.

But your complaint is one function of the main jet check valve. Preventing a
bog after you get off the throttle and then accelerate, and assisting the starting
is its 2 main functions.

When you chop the throttle, pressure increases inside the venturi. The check
valve prevents the sudden pressure increase from affecting the float diaphragm,
and causing a momentary lean spot.

You may want to look at the lever position. It may be lower than the casting.

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Another possibility. After a wot run for a distance, the exhaust temperature in the
pipe heats up and the increased heat raises the peak HP rpm (same as a shorter TL),
and decreases low end acceleration (similar to a shorter TL).

It is a common problem on sit downs.

Bill M.

Before you do anything, you should compare your current jet specs to the OEM
jet specs.

With the Ocean Pro arrestors you are probably going to want to be in the 20's for pop off.

I disagree with that.

 

[john zigler]

Change your spring to a 95 gram, open your low speed, and high speed screws a little, and re-test. With aftermarket flame arrestors you need to tune a little.