Problem with dual 44's-750SX

[Island750]

Just made the switch from a big single to a set of stock dual 44's on my 750SX. Has all the major mods- porting, pipe, head, stroker, case work, lightened flywheel etc. I was running a single 53mm carb and thought I would try dual 44's. I made sure I had a matched set, new rebuilds, new jets, new fittings, everything. Put it all together yesterday and when I went to start it, the carb for the rear cylinder is just spewing fuel through the "bombsight" directly into the throat.

Does this indicate a stuck needle/seat? Anything else? :dunno: I know I have to take it apart, AGAIN, but some direction may help with the downtime.

Thanks everyone!!:woot:

 

[Mile9c1]

Does it leak through the low speed holes too (under the throttle plate)?

I could be wrong, but it might possibly be a misaligned gasket under the main jet cover, or warped check valve.

 

[Island750]

It was just a result of way to sleep deprivation. I forgot to put a spring in for the needle and seat. What a dumbass I am. Fixed it already.

 

[MrSki]

Yeah - no prob. Fuel spewing out when you crank it over means the needle is wide open, not stuck closed. The other thing to watch for that has caught me, is when you put the spring in and lock down the screw, make sure the end of the spring is centered over the nipple in the arm. Otherwise, it can cock and give you the same results.

 

[Island750]

After all that I fire it up and find out that I have to change the springs again. The pop off is way to low. I get the dribble when she idles. :banghead: I may have to step the jet size down now as well, seems WAY rich on top, won't rev out. I am hoping that the springs will help, but I am fairly certain I will have to put smaller HS jets in.:17:

 

[Mile9c1]

What jets do you have in it now?

 

[SUPERTUNE]

Put in 2 check valves on the backside the metering plates also! Kawasaki's have stiffer motor mounts and vibrates the carbs to death and causes them to dribble out the fuel cluster.

 

[2XLR8]

Try a 2.3 with a 115 gram 115 low 130 mains. try 1 and 1/8 on low and 1 on high. This will get you close.

 

[SJ13]

Mike listen to supertune he solved all of my carburation problems!:hail:

 

[Island750]

I still have to get it in the water, but I have 125 HS in it now. It seems really rich, won't even rev out on the trailer, so I have to splash it and run it a little.

By the checkvalves, those are in the square section and are the small plastic discs right? I will try that when I pull them too.

Right now I HAVE to switch out the springs. :Banane01:

 

[Island750]

Switched springs and found another problem. The neddle and seat were messed up on the rear carb and this caused a VERY lean condition at high speed. I managed to catch it before any damage done though. Nothing like pulling the engine of your ski 5 times in two days. Anybody needs a Kawi 750 pulled apart, I'm the guy. I managed to pull the motor, rejet, put the motor back in and have it running in less than an hour. I'm not sure if that is good or bad yet.

Planning to finally splash it on Friday. Trying to get this thing ready for FSF.

Thanks to all for the help and support.

Chuck, these carbs may be on their way to you at seasons end to go through them. After Abe's praise of your skills, and everybody else's for that matter, I want to make sure I'm set up correctly.

 

[Ragged Edge Racing]

I ran my stroker 750 with BJ 44's and ran a 2.5NS with 120 lows and 115 highs. Port timing was only 188 though, just wide. I run these on my SXR with almost the identical setup except for 125 lows?? Something to think about.

 

[Island750]

Running pretty strong now, I still think I have to step up to 125 lows though, I ran it around and pulled the plugs, light tan in color, seems way too lean to me. I have to get on some calm water though. 3 foot rollers today made it tough to read jetting with the constant on/off throttle.

Seady 1/4 throttle and nailed it seemed good, lows might be lean, I was at 2 turns so I figure it best to jump up. Gotta get dialed before FSF this upcoming weekend.

Does plug color factor in at all?? I had a new set in and they stayed clean, switched to a well oiled pair and they are now light tan as well. I don't want to fry this thing, I can't afford a rebuild anytime in the near future.

 

[SUPERTUNE]

If your riding freestyle or wave jumping a light tan IS GOOD...My plugs will burn white if you ride closed course racing or flat out running. You shouldn't have a problem with being to lean. The check valve is the finger one (next to the main jet) not the fuel pump round ones!

 

[Island750]

On the back side of the half moon portion of the carb then, Chuck?

I rejetted because I got SCARED at the color of those plugs. In all my years of riding I've never had tan plugs.:bigeyes: So that means I was pretty close to the right jetting. I guess I will step back down then, I have the motor out again anyway.
Jetting that produced the tan plugs was 105 lows-1.75 turns out, and 120 highs 1.5 turns out. 2.3 N/S gold spring.

I was planning on jumping up to 110 lows to put a little more fuel in there, as I said I have never seen tan plugs, and I thought the next thing I was going to see was a fried engine.:banghead: Would I be worse off running the 110's or sacrafice durability in any way? I run 45 to 1 oil so I can run 40 to 1 for insurance I just would hate to detonate this engine, it's the best one I've ever had.