Need help with chasing down an air leak

[freestylegeek]

hmmmmmmmmmm..... turn the forced plenum x5555666.2 air induction system off....................

This is a weird one.......... crack in the carb bases?????? hard to see how the carbs could cause this short of the air adjustments or jetting being lean........ have you tried upping the low speed jet? I know, sounds trivial, but I think that is what you are going to find......... (something so simple)

The forced plenum air induction system (or turbocharger as most of us call it) is not turned on...

I'm going to try some full throttle blasts with the idle screw turned completely off, and see if it still does it. If that takes care of it, then something is fishy with the idle screw or throttle plates in that position.

 

[freestylegeek]

Oh, and jetting is:

Low - 105
High - 125
Pop-off: 18 psi

That's on the rich side of what Tim at NOVI recommended.

 

[waterfreak]

Hey Geek, try this set up. It was given to me by Mark (Malone's tech) I used the same set up and it is spot on!
Start with these specs
Pilot Jet- 130 L.S. 1.0
Main Jet- 145 H.S. 1.0
Valve Seat- 2.5
Spring- Gold 110 Gram

 

[RMBC Freeride]

I gotta agree with Harrison and Steve on this... your pilot jet seems too small, regardless of what Tim has suggested. Its worth a try at least.

I am running Novi's on 2 of my skis and they seem to be sensitive to pilot jet and low-speed screw settings. I had my SJ running great here, but both times I went to Pismo this year it wanted to free-rev. After the first trip I did the whole leak down hunt only to find nothing... jetted up on the pilot and brought the main down a little to keep the same total jetting # and it was better the second time in Pismo but still idling high. A quick turn to the screws and the idle adjuster and it performed flawlessly - even holding up to the pancaker's shredding (lots of air time = increased chances of free-revving)...

hope this helps. I can get you my jetting specs when I get home tonight if you want them?

 

[freestylegeek]

I gotta agree with Harrison and Steve on this... your pilot jet seems too small, regardless of what Tim has suggested. Its worth a try at least.

I am running Novi's on 2 of my skis and they seem to be sensitive to pilot jet and low-speed screw settings. I had my SJ running great here, but both times I went to Pismo this year it wanted to free-rev. After the first trip I did the whole leak down hunt only to find nothing... jetted up on the pilot and brought the main down a little to keep the same total jetting # and it was better the second time in Pismo but still idling high. A quick turn to the screws and the idle adjuster and it performed flawlessly - even holding up to the pancaker's shredding (lots of air time = increased chances of free-revving)...

hope this helps. I can get you my jetting specs when I get home tonight if you want them?

Absolutely man! Fire them off!

That's interesting to know that you had a similar experience... Looks like I'm heading out to the garage to pop the carbs off again!

I'm hoping I'll be able to compensate for my new riding conditions with just twisting the screws. The next few weeks of riding will be 50-60º air temps and 50-60º water temps...

 

[freestylegeek]

Hey Geek, try this set up. It was given to me by Mark (Malone's tech) I used the same set up and it is spot on!
Start with these specs
Pilot Jet- 130 L.S. 1.0
Main Jet- 145 H.S. 1.0
Valve Seat- 2.5
Spring- Gold 110 Gram

If it came from Mark, it's GOTTA be good!

 

[freestylegeek]

Thank you Neil and Steve! I can do full throttle blasts all day long now and she comes right back down to idle every time!

Earlier, when I still had the old jetting in it, I went to 2-1/2 turns on the low screw and that took care of it. After I re-jetted to Mark's specs for Steve's boat, I could keep the low screw at 1 turn and it worked fine. I ran it for about 15 minutes letting it idle for about 45 seconds at a time before giving it full throttle, and it was a little rich, but not too bad. I can't wait to get it in the water tomorrow!

 

[RMBC Freeride]

:Banane25: :bigok: :Banane09::bananajump::cheer2: :biggthumpup:
way to go Matt!!! glad to help!

I've got my 8mm in a new hull.... love it!!! details to come as soon as I can get a few pics and write up a thread.

 

[freestylegeek]

Update:

I put it in the water tonight for about 10 minutes. It's WAAAAAAAAY rich. It doesn't idle worth a crap, and after attempting to idle for about 15 seconds, it dies. When I try to start it again, it takes a REALLY long time (6-7 15 second starter runs). It almost runs the same way it did when I blew an o-ring. After looking at the plugs, I'm quite certain I'm not taking on any water from a blown o-ring.

Now what?!?!

I'm getting really REALLY fed up with this.

I wonder if Chuckie takes motors in on trade....

 

[freestylegeek]

After sleeping on it, I'm wondering if it's actually rich or not. If it were super rich, it would probably start fairly easily, right? It's only a struggle to start it when it's in the water. On the trailer, it starts fine.

Am I looking in the wrong spot? Might it be ignition related?

 

[SuperJETT]

After sleeping on it, I'm wondering if it's actually rich or not. If it were super rich, it would probably start fairly easily, right? It's only a struggle to start it when it's in the water. On the trailer, it starts fine.

Am I looking in the wrong spot? Might it be ignition related?

Total loss doesn't care if you're super rich, running 1:1 premix, or just straight water, it will still fire the plugs just about.

 

[Matt_E]

It will be tough to start when it's rich. More so under load.

 

[freestylegeek]

It will be tough to start when it's rich. More so under load.

So, if I open the throttle a little while trying to start, it should help it, right??
That's not the case.

 

[Matt_E]

Opening the throttle doesn't make it less rich, if the rich condition is caused by the jetting.

 

[RMBC Freeride]

Take a look at what you did... you went from a 105 pilot to a 130 and from a 125 main to a 145 main... thats a big jump up in total fuel being delivered. it is very likely that you are too rich now. Work your way back down, starting with your pilot jet.
I still need to check my Novi Jetting specs and let you know what I'm running. (although it really would only be another starting point )

 

[freestylegeek]

Take a look at what you did... you went from a 105 pilot to a 130 and from a 125 main to a 145 main... thats a big jump up in total fuel being delivered. it is very likely that you are too rich now. Work your way back down, starting with your pilot jet.
I still need to check my Novi Jetting specs and let you know what I'm running. (although it really would only be another starting point )

I'll take anything at this point. The fact that it runs funky doesn't concern me as much as the fact that it takes FOREVER to start when it's in the water...

I'd really appreciate those settings, Neil.

 

[QJS]

I used to do a lot with Novi's on race ski's and found that they nearly always ran best with backwards jetting, I can check my notes tomorrow but I think you are in the ballpark with the low speed but you need to take the high down to about 115. I also feel your pop off is a little on the low side, try using a 80 or 95gm spring.The problem with low pop offs is the vibration from the engine can shake the needle off the seat causing flooding, you can check this by looking down the carbs with the engine running just off idle (the point of maximum vibration) very often you will see fuel pooring down the carbs making for a rich bottom end and difficulty in starting, this condition is not so noticeable on race ski’s but for freestyle it’s a nightmare.
Hope this helps,
Chris.

 

[RMBC Freeride]

Thanks Chris, that reminds me... I think mine are reverse jetted also. All the more reason I need to check my specs and let you know Matt.

 

[freestylegeek]

I used to do a lot with Novi's on race ski's and found that they nearly always ran best with backwards jetting, I can check my notes tomorrow but I think you are in the ballpark with the low speed but you need to take the high down to about 115.

That's just about where I used to be when I first built this motor. I decided to change it after talking to Tim at NOVI.

I also feel your pop off is a little on the low side, try using a 80 or 95gm spring.The problem with low pop offs is the vibration from the engine can shake the needle off the seat causing flooding, you can check this by looking down the carbs with the engine running just off idle (the point of maximum vibration) very often you will see fuel pooring down the carbs...

YES!!! Without the flame arrestors on, it splashes fuel onto the head when idling.

...making for a rich bottom end and difficulty in starting, this condition is not so noticeable on race ski’s but for freestyle it’s a nightmare.
Hope this helps,
Chris.

I think that will help. I'll be doing some trailer testing tonight to see what the result is.

Thank you for posting Chris!!

 

[Matt_E]

YES!!! Without the flame arrestors on, it splashes fuel onto the head when idling.

Errr...that is indeed a problem. Raise that popoff until it quits dumping fuel.
Then work with the pilot to compensate.