2002 GTX Idles Well, WOT Stalls - New Fuel Lines, Filters

[cdnbikerdude]

Quick Synopsis

2002 951 engine with 35 hrs
Grey Fuel Lines Switched
Carb filters cleaned
Tried opening the Gas tank to make sure there wasn't a vacuum
tried running on RES
Cleaned Rave Valves
New Plugs and Gapped to .020"
Low Speed Idle screws turned to 1.75 from bottom
Will WOT (70mph) if you give it a quick choke first then release.


I have a 2002 GTX (Not Di Not RFI) that had problems of low RPMS and low power.

I took the advice from this forum and cleaned the carbs and changed all the fuel lines out.

THe machine runs much better now if you are able to get to WOT.

It idles fine, but if you punch the throtlle it will stall.

If you give it a quick open choke, release it, then WOT it runs fine. 60mph, 7100 rpm. If you let the WOT go it will go back to idle fine. If you try WOT again without a choke it will stall right out.

Any suggestions what to check next?

I have "tuned" the low speed idles till the cows come home and it doesn't seem to make a difference. I turned in both low speed idles and then back out 1.5 turns for a starting point. Too much turned it the engine won't start.

New plugs installed and gap correctly (.020)

Rave Valves have been cleaned.


Any help would be apperciated.


Thanks
Mike

 

[seadoosnipe]

Good work!...

So far, you've done good work......but you haven't completed the work from the grey fuel lines.

Your problem is your accelerator pump, located on the PTO carb. It controls the initial take off and maneuvering in the lower rpm ranges.

You'll need to remove your air box and flame arrestor to see into the carbs. You should see the pump on the PTO carb and a line that's running out of it and splits off, to both carbs. These two connect to the carbs brass inlet nipples. This is usually where the blockage is.

I used carb spary, with that little red, plastic tube to flush the gunk out of it. Then, you can wind back on the throttle cable to check that it works. The pump will only pump the fuel left in the lines, so you may have to start the engine at idle, shut it off, then look inside the carbs when you squeeze back on the throttle linkage.

 

[cdnbikerdude]

Awesome! I love this site!

We are going to go try this out right now. I do remember when I had the carbs off it was spraying only in one nozzle.


Thanks for the helpfull advice!

 

[cdnbikerdude]

Update:

We have both nozzles now spraying in both carbs but it is still doing a stall if you go wide open throttle both on land and water from idle.


If you give it a quick choke and then WOT it goes.

If you slowly try to ramp up to WOT it dies.

It sometimes will just putter around the lake at 3500rpm max as well (usually 2 ppl) and then bam it hits max rpm if you feather the throttle between idle and WOT.

Any suggestions what to check next? We have run out of ideas...

Thank you for your help.

 

[seadoosnipe]

Cams?

There is a cam on this too. Did you check to be sure the cam engages and squirts the fuel, as soon as the throttle plate begins to open? The synco on the accelerator is very important too. Sorry I didnt mention this too, but it's not normally messed with. But if they were removed and cleaned at any point, they may have.:cheers:

 

[cdnbikerdude]

Yes the cam is working. I never took this off while cleaning. They are both syncro'd as well with the arm. Everything ran fine before the carb cleaning (except low rpms). Now I have the power back, but stalling between idle and WOT.

I never took the needles out internal carbs (the one near the jets on the springs). I was worried about the POP off pressure, but after some more reading if I am just cleaning I don't need to do this test correct? Just return everything as is.

The plan for today is to take the carbs off again and go through carefully.

Anything else to look for?

Mike

 

[cdnbikerdude]

Update Monday

Ok we took the entire carb assembly apart again and cleaned everything. Carb cleaner to the whole works (ports). (minus the gaskets etc)

Put it all back on, same problem pretty much. Just bogged and stalled from idle to WOT. If you gave it a quick choke it will WOT or even ramp up to WOT fine.

After riding behind the wife for a bit (she hates going fast) I adjusted the choke so it is a little closed (say 10%) and it ran all day no problems. Came outta the hole full WOT no problems.

It looks like the diaphrams on the needle side (spring + needle) had a pin hole sized hole in each. Would this be something to worry about? We couldn't get parts today since it's a holiday in Canada.

Also any concerns about running with the choke a little closed?

I will pull the plugs tonight to make sure things are okay too.

Michael