Dual 44 Mikuni observations

[freestylegeek]

Alright guys, I've got some questions.
I've been reading Matt_E's thread about his carbs.
Well, here's what I've got and how I have them tuned so far.

My set up is a stock stroke, 85mm flattop, ported Lamey cylinder with 28cc domes (185psi) in a girdled ADA head.
Ported cases, 3.5mm Riva reed spacer, v-force delta II reeds, and stock flame arrestor w/ 2 screens removed.
My ignition is a 61x with a rev-limiterless 62T cdi, and 3 degree's of advance.
I have a factory 'b' mod, parallel cooling, and my top screw is open 1/2, middle closed, and bottom about 1/16.

Paul recommended this jetting:
120 L
110 H
2.0 and 95g spring

It worked fairly well but I always felt that it was kinda 'spongy' and wouldn't start without a little bit of throttle.

So I went back to this:
115 L
135 H
2.0 and 95 g spring.

It is a lot more 'crisp' and it starts immediately.

Why is this totally different than what everyone else is running (Wax, Paul, Matt_E, and more)?
AND why does it work so well for me?

Any interesting theories?

 

[nikad58]

62t porting or sleeved 61x ?

 

[Matt_E]

Well...what I am running (122.5L, 120H, 2.3/95g) was Paul's recommendation to me via phone, after telling him my setup.
I described my porting, but he didn't perform the porting, so to do the right thing, he gave me a recommendation that was more likely a safe starting point.
I only ran this for about one hour before folding up for the winter time.
Now that I am getting ready to head back out, I want to get it right.
Part of that effort included acquiring a Mikuni popoff gauge - which led me the 24psi popoff numbers.
I want to try different jetting, but I really don't want to buy every jet size from 105 to 120 in both pilot and main, for both carbs - it would cost close to $100 bucks.
Jared's jetting suggestions (Wax) are usually quite a bit different than other folks, but I observe them to pretty much always yield good results for folks. I think Jared knows what he's talking about.
That said, he runs drypipes. :Banane01:
Now we all know you can't trust those guys.

 

[Matt_E]

62t porting or sleeved 61x ?

Pay attention...Lamey! :biggrin:

 

[freestylegeek]

...I think Jared knows what he's talking about.
That said, he runs drypipes. :Banane01:
Now we all know you can't trust those guys.

LOL!!
I wondered about the dry pipe thing...
the wierd thing is Paul did everything for helping me set-up this motor...
I KNOW Paul knows his stuff, but for some reason, it doesn't work as well as the set-up I have going right now.
I'm wondering if it's the water up here, or the gas, or the operator of the boat...

 

[freestylegeek]

62t porting or sleeved 61x ?

What??
Those sound like Yamaha cylinders!
I scoff at them!
I am a Lamey man!! :biggrin: :biggrin:

 

[Mile9c1]

Ever try 130 highs with the 115 lows?

 

[SUPERJET-113]

:hail: :hail: LAMEY:hail: :hail:

 

[freestylegeek]

Ever try 130 highs with the 115 lows?

I may try that soon.
I'm debating on what direction I want to go.
My low speed screws are out at 2 turns, so I'd kinda like to bump up my low jet.
But my high speeds are also out around 1 turn, so I'm not sure I want to go down on my high jet. Granted, if I bump up my low, I probably would have to go down on the high.

 

[freestylegeek]

Update:

It turns out my original set-up (Paul's recomendations) was NOT what Paul recomended.
I had a 95g spring in the front carb, and a 65g spring in the rear. :banghead:
I don't have 2 95g springs, so I decided to try Paul's next recomendation: 120/2.0/115g

I left my 135H in, and did the rest.
I think that pop-off is too high.
It had a slight hesitation when I would hold it at 1/4 throttle for a bit then hammer it.
It doesn't rev very high, so I'm quite sure I'm rich on top, and that's making my hesitation not so obvious.

So, I'm gonna switch back to what Paul originally recomended - 120/2.0/95g/100

Here's what really makes me wonder though:
I also rode Chad's boat, and his rev'd faster and 'jerked' quicker than mine.

Here's his set-up:

• Squarenose
• 61x cases
• Z-force freestyle porting
• 81.5mm domed yamaha wiesco pistons
• 180 psi ADA girdled head
• single 44
• RAD flywheel
• MSD Enhancer
• Factory 'b' limited
• solas concord 13-16 3mm cutback
• 85mm bored raider nozzle
• stock cone

Here's mine:

• Roundnose
• 62T ported cases
• Jr Magoo's Honda/Lenzi ported Lamey Cylinder
• 85mm flat top Kawasaki wiesco pistons
• 180 psi ADA girdled head
• dual 44's
• 61x flywheel/stator
• 62t CDI (no rev limiter)
• Factory 'b' mod
• solas concord 13-16 3mm cutback
• 85.5mm bored superjet nozzle
• wet-wolf shortend cone.

I must certainly not have my stuff dialed in if his boat feels every bit as 'spunky' as (or slightly more than) mine.
I'm very pleased with the performance of my boat, but I'm a little frustrated as to why it's not like :bigeyes: WOW :bigeyes: compared to Chad's.
He seems to think that I don't have enough prop - the engine revs quick, but the boat doesn't quite follow.
He suggested putting the stock cone back in - which I will try on my next ride.


Any thoughts??

 

[Matt_E]

FWIW...Paul's recommendations are good starting points. For me, he gave me good recommendations, but since he doesn't know the specifics of my porting and every little detail of the engine, it's hard to give a spot-on jetting spec.

He told me to try 2.0/95g 117.5L / 110H. (Popoff is 24psi)

That turned out to be too rich, so I dropped the pilots to 115. I thought it ran well.
I guess I was wrong, because on the second tank I rode on today it ran horrible. WHat changed? Yesterday, I ran a 24:1 break-in tank. Today, I switched to 40:1. Considering how bad it ran today (loading up horribly ), it must have been borderline way too rich yesterday.

I seem to remember that last year, when I switched from a Speedwerx pipe to a B-Mod pipe, I left the jetting the same. I later found out that was too rich and dropped the pilot 10 (!) points, and it ran awesome. But it ran fine before too...leading me to believe that there is quite a wide margin between very noticably too lean and very noticably too rich.
I will drop the mains to 105 and the pilots to 112.5 (or lower) and go from there.

 

[D-Roc]

that is almost like smitty's old boat minus the TL ignition and anyone that rode his old setup knows that it was a arm wrencher, even with his 38's. last time i was there we brought him a stock cone as well cause he wanted to try one.

 

[Mile9c1]

Definitely try a stock cone or a stock nozzle.

Do you have a popoff gage?

 

[norcal ex]

maybe you need an ignition?

 

[Matt_E]

That cylinder shouldn't need a total loss to wake it up...compared to the other motor, anyways.

But I agree....a TL is worth the money.

 

[norcal ex]

im not even saying total loss... an enhancer should help him out...i dont have an enhancer yet, but swithing froma 61x to a fully ported 760 already kills my arms.

 

[Matt_E]

OKay...gotcha.

 

[waxhead]

interesting reading
the figures i am giving you matt are for a b-pipe and what i would run
or close to it its hard to give a figure for some ones ski if you dont know to much about it
but this would be my starting point

 

[freestylegeek]

im not even saying total loss... an enhancer should help him out...i dont have an enhancer yet, but swithing froma 61x to a fully ported 760 already kills my arms.

I was hoping you weren't going to say enhancer....
I can't see that making THAT big of a difference.
But, maybe that's the missing link.

 

[freestylegeek]

that is almost like smitty's old boat minus the TL ignition and anyone that rode his old setup knows that it was a arm wrencher, even with his 38's. last time i was there we brought him a stock cone as well cause he wanted to try one.

It's still an arm jerker, but so is Chad's.
I'm hoping that stock cone may help a little.