Frustrated with a possible fuel problem!

[airlar73]

Ski is a 97 XP, and I've done the following:

-replaced solenoid (it was bad)
-changed out all fuel lines (no more grey)
-checked fuel selector, main and res both work fine
-cleaned fuel filter
-drained tank, filled with new gas
-rebuilt carbs with new needles and seats, internal carb filters, diaphrams and gaskets... used original springs
-blew through all check valves to ensure there were no clogs
-checked all fuses in the box (including the one that masquerades as a plug)
-installed new and correctly gapped plugs
-trimmed spark plug wires 1/4" (I'm getting great spark, so no issue there)

Everything is cranked down tight, so no air leaks, but I get two beeps (from the new buzzer) I can get it to fire if I choke it or if I squirt premix into the carbs, then it will run from anywhere from half a second to 5 seconds before dying. After it fires it will only give me the alarm tone if I hit the start button, so I am forced to pull the DESS key and put it back on to try to get it to fire again.

I have read every post relating to this that I could find and exhausted every possible option before posting.

Any ideas?

 

[timmyboy76]

Had similar situation, ended up being a low/bad battery. Also, re-check your fuel lines, make sure they're in the right places.

 

[airlar73]

Also forgot to mention it's running on a brand new battery, popoff pressure is 40 on both... I'll go back and check the fuel lines - it also emits an ear piercing gunshot-style backfire after we fire it up a few times, if that helps

 

[roneagan@cfl.rr.com]

Rotary valve

Did you have the rotary valve off?? Almost sounds like a timing problem with the backfire..

 

[airlar73]

I had the RV cover off about 3 yrs ago when I replaced the motor, but it ran fine last year and the year before that. I ripped the carbs back off and found one of the smaller of the two internal carb jets plugged with what I imagine is residue from the grey lines... I must have missed it during the rebuild. Would that tiny cause all that havoc though?

 

[jhjesse]

oooohhhhh yeahhhhh!!!!

 

[airlar73]

OK, so now the carbs are all spic n span, I get my two beeps, start her up, she idles beautifully for anywhere from 1 second to 5 or 6 seconds, then shuts off like I pushed the stop button. It (usually) immediately beeps twice again, and then I can start it right back up only to have it shut off again. Never sounds like it's struggling for fuel or anything...

Possible bad DESS post or bad MPEM??

If it ain't one thing it's another...