Ski wont rev up!

[norcal ex]

yes, i adjusted the only adjusters that are on the carbs. i dont understand what you mean by the other things. i put those new jets in it already. i dont think im understanding. explain? i just read the tuning instructions and they were along the line of what i did...

 

[Matt_E]

No....unfortunately, there is a lot more to properly tuning a carburetor than throwing in a jet and turning adjusters.
Once again, if you are using the low speed adjusters to change throttle response, you got a very fundamental misconception on how those carbs work.

I outlined the complete tuning procedure a couple of posts above.

You are getting close - but to get it running optimally, you need to start with the low adjusters for a proper idle, pick the right pilot jets (what you got now is close, but I think you need more than one size to tune it - and please resist the urge to tune an improper pilot jet with the lo adjusters!), re-do the low speed adjusters, find the right main jet size, and properly adjust the hi speed adjuster.

Additionally, to really find the optimal setup, you should try different popoff pressure/pilot jet size combinations. The popoff circuit and the low speed jet circuit work in conjunction with each other -there are several different ways to make it work.

I hate to say it, but an hour is rarely enough to properly tune carbs. I spend probably a good six to eight hours total to find the best combo for me.
It was worth it - the power difference between "Eh, I think it's good!" and "It's tuned right" is worth the time invested.

 

[norcal ex]

the 6- 8 hour time frame is not for a 38 is it?

thats what i thougt (about changing the pilot) i want to change it to 77.5 and change the popoff pressure. i dont know if i should lower it or higher it?

once the idle was set good i didnt mess with the low screws. i mostly turned to top screws. as i said before, the ski would not rev up at all with the high speed adjusters below 1.5 turns out. but onceit was 1.5 it ran much better. whish makes me think that i need to make the pilot jet higher, but it does not feel lean at all, it feels fat. i can hold the throttle wide open and barly move (7mph) but after 3 seconds the ski will rev up and feel fine at top

 

[Matt_E]

Your hi speed adjusters say very little about your pilot jets.

There are five separate circuits in the carb that all need to be tuned in the right order.
How did you set the idle?
What is the popoff now?

 

[norcal ex]

popoff is stock. i set th idle by putting the pump in the water and running the ski and adjusting it slowly till the ski ran the best.

the reason i think it is the pilot is because the ski feels loaded up until the ski revs up. th elow end feels so weird....no resonse at all!

 

[Matt_E]

First off, I would drop the popoff springs to 95g. Are you using stock flame arrestors? If so, did you remove any screens?

Let's try to get you further. Lower the popoff and put 80 pilots in it. Don't forget to readjust your idle.
When you adjusted the idle, you adjusted it with the low speed adjuster screws, correct?

 

[norcal ex]

the pilots are already at 80. yep, i used the low speed screw.


i have an aftermarket flame arrester, they look like high flow ones. what is the stock popoff pressure of the stock spring, 115? ill get it all done tommarow after school and take it to the lake and let you know what happens

 

[Matt_E]

Okay, I didn't realize you were at 80 already. Besides, I was thinking in the wrong direction anyways.

I am thinking your pilots are too rich...I realize you said it ran better with the high speed adjusters further out. However, I really don't think that's saying all that much about the pilots.
Stock springs are 115.
Drop some 95's in and lower the pilots to 77.5 or even 75. Don't forget to readjust the low speed screws.

 

[norcal ex]

alrite cool, i will do it tommarow. Thanks matt for your help. it is greatly appriciated!!!

 

[Matt_E]

No problem...I know what it's like.

 

[norcal ex]

ALRITE... i tested once again today! this time the ONLy thing i changed was the spring. i put a dull silver one in. 95 grams. took it out and it felt the same as yesterday on the trailor. it only reved up once while on the trailor. i adjusted th low screw for the idle and then i adjusted teh top screw. i went all the way in to all the way out and i found a happy spot at 1 3/4. i took it off the trialor and rode it and it would not rev up as ussuall, but it was having a much better low end instead of 5-7 mph it was going over 10. then it started to rev up and it felt pretty good. if i had it wide open for a while it would start to die when i let off the gas and tryed to hit it again. it felt by far the best today than it ever has. for a few seconds while riding it actually felt like it did have some bottom end. once it got cleared out if ran much better.... should i put that 77.5 in and try it again?

 

[SUPERTUNE]

Sounds like you need to find someone like me in Ca and take it to them to sort it out...

 

[norcal ex]

i have built numerous engines and skis and have NEVER had a problem like this....i think something is messed up, but i dont know what. i have switched everything out and nothing changes it....

 

[Matt_E]

I think you are rich on the pilot. Adjusting the hi speed screw will do very little for your bottom end response.
Go down to 77.5 pilots.

 

[norcal ex]

thats what i thought. ill do that and test on saturday. i didnt want to change two things at once, then i wont know if i made it better or worse or what

 

[Matt_E]

Lowering the popoff actually makes it richer down low, but with those flame arrestors and a pipe you needed to lower it somewhat.

 

[norcal ex]

so keep that spring in there...correct?

 

[Matt_E]

Yes.