Unequal cylinder temps on tpe 964

I’m use to seeing some moderate temp differences in 62 t base motors I’ve had in past but current 964 is running much hotter on front cylinder in and out of water. Plugs read sim on both. Anyone experience this ?
 
What carbs and manifold
Fs49 boyseen intake rrp pipe enlarged fittings for dual cooling. Equal length water lines in and out of billet head. Plug reads are similar. Msd tl new coils and plug wires Motor doesn’t run hot in water but front Cylin is always considerably hotter.
Balance water routing
Normally I’d think partially blocked cooling lines or uneven size fittings lines ect. But temp diff on trailer running for 15 secs or so before heat soak is even more evident temp difference
 
I’m use to seeing some moderate temp differences in 62 t base motors I’ve had in past but current 964 is running much hotter on front cylinder in and out of water. Plugs read sim on both. Anyone experience this ?

My Dasa did that as well... think it was around 14 deg difference On mine @ the time, you could feel it with your hand as well... very odd.... frt cyl hotter than rear cyl.... no amount of water adjustment with different restricter for each cylinder changed it...

I noticed the rear carb, 49fs, dribbled at idle and on full throttle snap and elsewhere in rpm range. This dribbling was the cause, the extra dribbling fuel cooled the cylinder..

The front warmer cylinder was normal
It’s the cold cylinder In my case with the issue...

The best fix for the dribble in my case (wasn’t raising pop off or smaller seat or extra check valves)

It was changing the kidneys to a different model, the bore under the check valve flap “the clear check valve” is different, instead of straight thru bore this one makes a 90 deg turn and opens in a different location...

I’ll look and see if I can find the part number I used.. they were like $80 each
 

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My Dasa did that as well... think it was around 14 deg difference On mine @ the time you could feel it with your hand as well... very odd.... frt cyl hotter than rear cyl.... no amount of water adjustment with different restricter for each cylinder changed it...

I noticed the rear carb, 49fs dribbled at idle and on full throttle snap and elsewhere in rpm range. This dribbling was the cause, the extra dribbling fuel cooled the cylinder..

The front warmer cylinder was normal
It’s the cold cylinder In my case with the issue...

The best fix for the dribble in my case (wasn’t raising pop off or smaller seat or extra check valves)

It was changing the kidneys to a different model, the bore under the check valve flap “the clear check valve” is different, instead of straight thru bore this one makes a 90 deg turn and opens in a different location...

I’ll look and see if I can find the part number I used.. they were like $80 each
Thanks man. It’s funny I was just asking someone else about fs49s and how to stop the annoying rear carb dribble. Mine are doing same thing. He had moved the return jet from a 65 that I’m using to a 110 to lower fuel pressure.
I have Brand new doubled up check valves and new n&s That didn’t help much. These only do it when idle gets low and motor starts vibrating more. Now that idle is smoother it’s much less. That does make sense though. It’s off over 20 deg and easy to feel with hand. I forgot what laser temp was but it was a lot diff. Ran against dock with proks off. Fuel delivery at least looks very even through rpm range
I’m getting 1/4 inch vertical wear stripes in my front cylinder a bit worse than the rear cylinder also. Using 40:1 klotz. Bore clearance was double checked as well when rebuilt. I just don’t get how that much wear is happening on motor with less than 5 hours. Deff send me the source you got the part from. Worth a try.
 
Yamahapartshouse.com

Mine dribble was more noticeable at idle like you mentioned, I also noticed visually The sloppiness Of it as I opened the throttle as compared to front carb..

Here’s a pic, I don’t have a side pic handy.. noticed the hole is plugged in the photo and it’s relocated to the side and if my memory is correct, a higher position
 

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There was a thread recently with talk about differences in timing for front and rear cylinder on msd tl, have you checked both to make sure one is not off?
 
There was a thread recently with talk about differences in timing for front and rear cylinder on msd tl, have you checked both to make sure one is not off?
Traditional msd dual channel billet plates do NOT have the pickup triggers 180 apart. Depending how you are wired either the front or rear cylinder has advanced timing relative to the other. I recall I measured the difference and it was 2-3 degrees different. 2 seems to stick more than 3. The trick to get same was slot the msd pickup itself. 2-3 degrees advanced could produce more heat given everything else equal. A second reason could be the exhaust manifold you are using and it’s length of lines.
 

Quinc

Buy a Superjet
 
Thanks man. It’s funny I was just asking someone else about fs49s and how to stop the annoying rear carb dribble. Mine are doing same thing. He had moved the return jet from a 65 that I’m using to a 110 to lower fuel pressure.
I have Brand new doubled up check valves and new n&s That didn’t help much. These only do it when idle gets low and motor starts vibrating more. Now that idle is smoother it’s much less. That does make sense though. It’s off over 20 deg and easy to feel with hand. I forgot what laser temp was but it was a lot diff. Ran against dock with proks off. Fuel delivery at least looks very even through rpm range
I’m getting 1/4 inch vertical wear stripes in my front cylinder a bit worse than the rear cylinder also. Using 40:1 klotz. Bore clearance was double checked as well when rebuilt. I just don’t get how that much wear is happening on motor with less than 5 hours. Deff send me the source you got the part from. Worth a try.

With the dribbling in the rear carb, that rear cylinder is getting more fuel and oil than the front cylinder..... so it may be masking normal wear... as compared to the front cylinder
 
Those kidneys are also in the gp1200 46i carbs. Might be cheaper to pick up a rack of carbs on ebay then buy the kidneys individual.
Quinc,

I like how you operate.

Always finding and sharing the proven "Equivalent or Equal" Part, Package or Modification at the lowest price for anybody on a restricted budget.

I've copied and pasted your Zeeltronic Budget Package and SuperJet Most Performance Bang-For-The -Buck Package to my Jetski Library.

Appreciate the Good Tips.

Thank You.
 
Traditional msd dual channel billet plates do NOT have the pickup triggers 180 apart. Depending how you are wired either the front or rear cylinder has advanced timing relative to the other. I recall I measured the difference and it was 2-3 degrees different. 2 seems to stick more than 3. The trick to get same was slot the msd pickup itself. 2-3 degrees advanced could produce more heat given everything else equal. A second reason could be the exhaust manifold you are using and it’s length of lines.
MotorHead,

Why would MSD do this?

Crank Twist? Magneto Heat?
 

Quinc

Buy a Superjet
Quinc,

I like how you operate.

Always finding and sharing the proven "Equivalent or Equal" Part, Package or Modification at the lowest price for anybody on a restricted budget.

I've copied and pasted your Zeeltronic Budget Package and SuperJet Most Performance Bang-For-The -Buck Package to my Jetski Library.

Appreciate the Good Tips.

Thank You.
 
MotorHead,

Why would MSD do this?

Crank Twist? Magneto Heat?
I was told in 1997 or 1998 or around that time, when I complained to MSD, that it was so the rear cylinder (if wired properly) would be retarded from the front. Few people commented back in late 90’s/early 2000’s on rec.sport.jetki before forums. Very few people in the Freeride community ever commented (shows how many people actually tune their own stuff. I recall Chucky? Chiming in that this was a known design). I’m guessing most plates out there are still same. Haven’t used TL on a twin since 04’. Timed a ton for buddies and everyone was off front to back

you can actually see they are not 180 by starting at a plate!
 
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Quinc

Buy a Superjet
I was told in 1997 or 1998 or around that time, when I complained to MSD, that it was so the rear cylinder (if wired properly) would be retarded from the front. Few people commented back in late 90’s/early 2000’s on rec.sport.jetki before forums. Very few people in the Freeride community ever commented (shows how many people actually tune their own stuff. I recall Chucky? Chiming in that this was a known design). I’m guessing most plates out there are still same. Haven’t used TL on a twin since 04’. Timed a ton for buddies and everyone was off front to back

you can actually see they are not 180 by starting at a plate!

Does the ATP TS2 have this issue as well?
 
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