pulse nipple on a 1994 650cc GTX

[alpinewhite]

Hi,

I replaced the case on my 94 GTX. The only difference between the new case and the old one is as follows: Old case, pulse nipple is on fore cylinder (front cylinder near magneto). New case, pulse nipple is on aft cylinder (cylinder nearest pump). I put everything back together and the ski won't start and backfires. Was it ok for me to use the back (aft) pulse nipple to plumb to the fore (front) carb? Is there timing on the pulse nipple? If so, I now plumbed what used to be for the front cylinder to the rear cylinder.

Thanks in advance.

 

[Bills86e]

That is for the fuel pump to operate. Just a push/pull pulse.

Did you use a timing degree wheel on the rotary valve when you installed it? It could be off a tooth or flipped and a 1/2 tooth off.

An air leak anywhere into the case (intake manifold, carb base, crank seals) can cause backfireing.

 

[seadooya]

or your rotory valve setting is 180* off. With the front(mag) piston, at TDC, is the mag/front port hole opened? if not, thats the problem.

 

[alpinewhite]

Yes, I confirmed that the rotary valve timing is correct. I also confirmed the presence of spark on both cylinders. The only other thing I could think of is that there is still no fuel in the carbs as I haven't fired this up in a couple of years. Tomorrow, I will try some ether just to see if it sputters at all.

 

[voodoo]

Go easy with ether, a runaway with no oiling can be very short-lived, your question about the pulseline is answered that both ends do the same thing with pulsing to make the fuel pump work - try to route the line upwards so if oil were to build-up it could drain back into the case, if you were to see the cases sitting together you would notice both ends have the place where it could be added, I had this piece broken off when I removed my first motor job and being new to this world I tryed hunting down the replacement which was never offered, I learned this after a few trips to the seadoo shop 2 hrs away and finally one of the older servicemen showed me one he was working on and how to drill and tap a 1/8 pipe thread so a short nipple could be put in there and close the other one which I handsomely goofed up by filling that mess with jb-weld epoxy stuff, 3 years of riding and no trouble including trips to Canada.

 

[alpinewhite]

voodoo,

Isn't oil injected into the rotary valve regardless of whether the carburetor is providing gasoline or ether?

 

[seadooya]

ether is ALOT hotter burn...i know what yuor saying, but the oil is being injected to the "bottom" of the case, then needs to come up from there to the journal ports, the non top of piston. Your dumping it right into it thru plug holes. Remove the inline filter white basket, dump that gas into the spark plug holes, the n giv a try.