OEM 760 44 carb throttle valves

[Roseand]

Planning on replacing my shaft seals so going to do throttle valves/butterflies as well.
I read something where super tune said the Oem 760 44 valves are different than the ones that come on the single 44s therefore not the same ones that come in the mikuni rebuild kit.
Can anyone else verify if there's a difference?

 

[waukie]

They are differant, 16° if mark on plate is 160

 

[Roseand]

They are differant, 16° if mark on plate is 160

Is that going to drastically affect my tune and how the carb works?

 

[Big Kahuna]

I would say yes. For some reason there is a difference. Stick with the matching set.

 

[Quinc]

Save your cash and pick up some 46's instead.

 

[Big Kahuna]

Why? He is running a smaller motor. 44's are just fine for it!

 

[Storbeck]

Is that going to drastically affect my tune and how the carb works?

My assumption is that the 16 deg is the angle of the throttle plate when it's fully closed. If that is the case a different angle would have a different relationship between throttle position and the progression holes. I think that matters.

 

[Roseand]

Save your cash and pick up some 46's instead.

I've thought about that! But honestly I have no desire to switch to 46s. More money, burn more fuel, and I have a setup that is completely dialed in with my current carbs. Having a tuned ski that does what you want and that you don't have to tinker with is worth ALOT imo, especially when your season is short!
When I first started riding skis all I did was mod and tune. Now I'm over that and just wanna ride! Not to mention, the mentality of having to upgrade something just because it needs to be fixed can be quite expensive!!!

 

[Storbeck]

What's wrong with your existing throttle plates?

 

[Roseand]

I would say yes. For some reason there is a difference. Stick with the matching set.

What's wrong with your existing throttle plates?

Well I need new seals and I figure I might do an overhaul while it's apart. Plates have some wear on sides/back and forth play. I haven't tried to remove them yet, but I'm assuming it might be difficult to pull them out without damaging them. Unless, I cut the shaft, then straighten the edges of the plate and pull em out.

 

[Big Kahuna]

plates come out easy once you get the screws out. May have to drill out. but at that point, they lift right out.

 

[Storbeck]

plates come out easy once you get the screws out. May have to drill out. but at that point, they lift right out.

In my experience, this is not the case when the edges are deformed.

 

[Roseand]

The ski was running good enough for me so if I can salvage the plates I'll just reuse them. But would prefer not to.. Pretty sure once they wear that makes them wear out even quicker when there's play?

Also, the real reason I'm doing this is because of the oily discharge coming out of my shaft seals covering my whole mani and carbs. I'm assuming thats from bad shaft seals unless it has something to do with my damaged reeds shooting fuel back up my carbs..

 

[Big Kahuna]

What size motor you running now?

 

[Roseand]

What size motor you running now?

820 5mil

 

[Storbeck]

I recently have picked up two different sets of carbs used that were described as "perfect condition"...which was true...except for worn throttle plates. So this issue has been on my mind lately.

This post here:

http://www.x-h2o.com/index.php?threads/throttle-shaft-plate-wear.184162/#post-1939061

tntsuperjet points out that the cause for this is that the throttle shaft isn't properly shimmed to prevent side to side play. Make sense to me.

So when I rebuild my carbs I will be carefully shimming the throttle shafts on the outside of the carb bodies to have minimal side to side play.

 

[JetManiac]

I recently have picked up two different sets of carbs used that were described as "perfect condition"...which was true...except for worn throttle plates. So this issue has been on my mind lately.

This post here:

http://www.x-h2o.com/index.php?threads/throttle-shaft-plate-wear.184162/#post-1939061

tntsuperjet points out that the cause for this is that the throttle shaft isn't properly shimmed to prevent side to side play. Make sense to me.

So when I rebuild my carbs I will be carefully shimming the throttle shafts on the outside of the carb bodies to have minimal side to side play.

This is more of any issue with a/m dual carbs often not aligned well, etc. OEM dual carbs have different linkage and setup which seem to last longer.
Roseand has oem dual 44s from a 760 so they are probably at newest about 20 years old, so they lasted pretty well.

 

[Roseand]

Here's a couple pics. They're not too bad.
@JetManiac can you verify anything about the 160 throttle plates?

And is that excess gunk just from bad throttle seals or an underlying issue?

 

[Storbeck]

This is more of any issue with a/m dual carbs often not aligned well, etc. OEM dual carbs have different linkage and setup which seem to last longer.
Roseand has oem dual 44s from a 760 so they are probably at newest about 20 years old, so they lasted pretty well.

I agree. Both of my sets had aftermarket linkages (it was a set of 46's and an old set of Novi 48's).

But even the oem carbs, especially at 20 years old, can have a little free play. You can see it in his picture, and I have a set of oem 44's that were about the same. I'm just saying I'd be paying close attention to this when rebuilding the carbs. Very likely it will come out nearly perfect with fresh oem parts.

@JetManiac do you have blades for the 64x carbs?

 

[Storbeck]

Also while we're on the subject, loctite on the little screws seems prudent. I debated between red (more confident it won't come out and go through the motor) and blue (more confident I can get it apart if i ever need to in the future).

I haven't decided. Any thoughts?