Total Loss/Jetting Questions

[sqwidget]

I recently bought a motor which is a 62T case with 61x cylinders bored out to a 760, im running dual 44s with a 112.5 pilot and a 140 main. Im not sure about the air/fuel screw or anything else on it right now. And then a few days ago i bought a total loss off ebay which came off of a 94 waveblaster. Now my question is am i on the right track with the jetting? what should the air/fuel screw be at? And now with the total loss, im pretty much clueless as how to set that up. Will I be able to just bolt it on and go? Or will I have to change lots of things on it?

 

[Etheraldreamer]

i dont want to intimidate you or make you nervous, but you just opened a huge can of worms for yourself. Lots of variables. Going to take longer than you think to get where you want it i would imagine.

 

[sqwidget]

Yeah thats what i figured, so i thought i should ask on here with people who actually know what they are doing.

 

[SUPERTUNE]

Not enough info on your setup...
Do You have a new 2 channel digital MSD Ignition?
What 44' carbs, OEM or aftermarket?
Intake manifold and reeds? What pipe... wet or dry?
What compression and fuel are you running?
What impeller pitch and any pump mods?
Are you good with timing tools and basic knowledge of engines?
Do lots of reading up on the subject first, read every thing you can find.

 

[masterblaster]

listen to this guy hes on top of everything,nice to answer these kinda ?s as well

 

[sqwidget]

Not enough info on your setup...
Do You have a new 2 channel digital MSD Ignition?
What 44' carbs, OEM or aftermarket?
Intake manifold and reeds? What pipe... wet or dry?
What compression and fuel are you running?
What impeller pitch and any pump mods?
Are you good with timing tools and basic knowledge of engines?
Do lots of reading up on the subject first, read every thing you can find.

This is the total loss that i have. http://cgi.ebay.com/ebaymotors/ws/e...0366428522&viewitem=&sspagename=STRK:MEWAX:IT. I have stock 44s with stock intake and reeds and stock exhaust. I have 180psi with 98 octane gas. Im not sure about what pitch impellar but its not stock, but the pump is. And im not so good with timing tools, but my dad knows a lot about it.

 

[augustaf]

Are you using an oem yam 44 manifold ? (it has a crossover), that would make jetting difficult to impossible unless you fill it in.

 

[sqwidget]

Umm im not sure. What does the crossover look like?

 

[augustaf]

It's a channel in the oem 44 intake manifold casting which connects #1 and 2 runners. Seems to work on couches. The oem manifold is painted

 

[Waternut]

Do the total loss after you've gotten the ski running right first. Total loss is a beast the first time you do it anyway. You don't want to over complicate the installation by not having the ski run right before hand. However, I can't imagine ever going back from total loss. I've put a lot of time into both of my ski's because of total loss but it's just so awesome that it's worth it!

 

[sqwidget]

Id do that, but the thing is I had to replace the stator, so I just went with this. So it wont be able to run without it on.

 

[sqwidget]

What about just installing it and trying it as is?

 

[sqwidget]

anyone?

 

[SUPERTUNE]

Old style MSD TL, Too much trouble for me.
Example: Hard starting, wear down the battery fast, and sometimes the chips that plug in them don't do as they say...
They also have poor battery life because they're an analog ignition, not the newer power friendly digital ignition MSD -TL.
http://www.msdpowersports.com/pwc_multi-channel.html

 

[sqwidget]

So I installed the old stator and ebox, so now my question is on jetting. Im running 135 main jet, 115 pilot. Im not sure where to start with the high and low speed screws either. But hows that sound so far?

 

[augustaf]

Not enough info on your setup...
Do You have a new 2 channel digital MSD Ignition?
What 44' carbs, OEM or aftermarket?
Intake manifold and reeds? What pipe... wet or dry?
What compression and fuel are you running?
What impeller pitch and any pump mods?
Are you good with timing tools and basic knowledge of engines?
Do lots of reading up on the subject first, read every thing you can find.

Yo, sqwidget, please try to answer supertune's question. None can help if you don't say what kind of manifold/ carbs you are using. OEM?

 

[sqwidget]

Yo, sqwidget, please try to answer supertune's question. None can help if you don't say what kind of manifold/ carbs you are using. OEM?

I did say. Check up a few posts

 

[SUPERTUNE]

You should fill the crossover passage in the intake with 2 part epoxy if using a stock 760 Yamaha manifold.
I don't have any jetting spec's written down for the stock 44mm 760 carbs except some stuff I did on a WaveBlaster II with a 760 stock engine.
I didn't have any good results with the OEM stock 760 carbs on MY modified engines.
There are some engine builders/rider here that have had some success with using them...I just didn't ever get them to perform to my high standard of consistently and power.
They are OEM carbs that Mikuni makes for Yamaha to Yamaha spec's, they have to pass a fuel consumption and emission standards for their application and have way different internal circuitry in them that are not user friendly for a high performance application.
Your much better off to use a set of aftermarket retail 44/46 mm carbs for a high performance application.

 

[sqwidget]

Yeah I'd do that, but I just bought this new motor and I'm kinda all out of money at the moment, so I'm just trying to get it all going right now so I can at least ride it. What kind of other carbs/intake would you suggest that I use? But if there's any suggestions that you would have for me right now, that would be wonderful.

 

[SUPERTUNE]

A set of aftermarket 46's that we rework the fuel circuit and set the jetting up for.
Boyesen Rad Valve intake system is the best to go with as this will support just about any bigger/more HP engine you want to build for the future so this will save $$ for the long run if you upgrade the engine for more power.