Backfire-no start

[FlightPlanDan]

'04 rn sj, runs fine til I shut it off. Turns over fine. Spark is there. Fuel is there. Compression is there. And it will backfire after spinning over for a while.
I'll figure it out eventually. Just thought you all might save me some time!

I know timing, though unlikely, can cause backfire.
I know flooding can as well....(this is where I'm leaning) carb clean, needle not seating?

Or plug wires? I changed plugs multiple times. Each time it would fire, run fine....then do the same thing when I cut it off.

Any help will be greatly appreciated!

 

[Idok]

more abouot the backfire.....did you have any big ones?

are they thru the carb or exhaust?

 

[FlightPlanDan]

more abouot the backfire.....did you have any big ones?

are they thru the carb or exhaust?

yes. and I think I know what you're thinking. The exhast hose was doing some awesome "flex action". Hoping no major damage.

 

[Idok]

yes. and I think I know what you're thinking. The exhast hose was doing some awesome "flex action". Hoping no major damage.

so tell me padawan, what am I thinking?

:bump:

 

[FlightPlanDan]

so tell me padawan, what am I thinking?

:bump:

Gaskets?

 

[FlightPlanDan]

so tell me padawan, what am I thinking?

:bump:

crank seal?

 

[keefer]

Weak or no spark initally, cranking fills the exhaust with fuel/air and then when it does spark, BOOM.

Pull the plugs after riding for a while and check for spark. Suspect bad plug wires, bad coil, or maybe a flakey CDI. Check the electrical box for water and all internal connections. Also ohm out the stator & pay close attention to the charge and pulse coils. Brown wire to ground and white/red to ground. The green wires are the lighting coil for charging the battery, they won't affect if it fires or not. Also check the integrity of the black ground wire from the stator. Lots O ohm checks, but this will get you started. Wiggle the wires where they enter the E-box and the flywheel cover while ohming to check for bad wires coming from the stator.

 

[FlightPlanDan]

Weak or no spark initally, cranking fills the exhaust with fuel/air and then when it does spark, BOOM.

Pull the plugs after riding for a while and check for spark. Suspect bad plug wires, bad coil, or maybe a flakey CDI. Check the electrical box for water and all internal connections. Also ohm out the stator & pay close attention to the charge and pulse coils. Brown wire to ground and white/red to ground. The green wires are the lighting coil for charging the battery, they won't affect if it fires or not. Also check the integrity of the black ground wire from the stator. Lots O ohm checks, but this will get you started. Wiggle the wires where they enter the E-box and the flywheel cover while ohming to check for bad wires coming from the stator.

will do! I'm gonna eliminate all the "simplest" possibilities 1st. Can't get into it til after work today. Input appreciated!

 

[keefer]

Good luck, intermittant electrical probs are PIA. Things will appear to check good until they warm up and then fail.

 

[FlightPlanDan]

Good luck, intermittant electrical probs are PIA. Things will appear to check good until they warm up and then fail.

yea,,pia. Have you ever heard of a crank seal blowing out from backfire?

 

[Idok]

if you want to bring it over tonite we can take a look......Going to the point at noon ish to catch in the incoming tide..

last REVscream ride before disassembly

pull the coupler cover, check the rear seal..thats quick and easy

maybe s/s switch or even just a loose connection

 

[FlightPlanDan]

if you want to bring it over tonite we can take a look......Going to the point at noon ish to catch in the incoming tide..

last REVscream ride before disassembly

pull the coupler cover, check the rear seal..thats quick and easy

maybe s/s switch or even just a loose connection

I thought you guys were riding today. It was small but nice yesterday. especially after the storm blew thru.

I'll do my best with it, with frank's help, hopefully we can figrue it out b4 dragging it over there.

 

[Idok]

riding at noon! waitin on the tides..

 

[NVJAY775]

You may have sheared the flywheel key. It will cause the same symptoms. That's what mine did.

 

[FlightPlanDan]

You may have sheared the flywheel key. It will cause the same symptoms. That's what mine did.

Thanx, I'll check it. But would your ski run at all with a broken key? Cause I did get it to run, and it ran good, but would'nt start again after shutting it off.

 

[sflsurfrider]

have you tried cranking with the stop switch disconnected?

do you have an MSD enhancer?

 

[FlightPlanDan]

have you tried cranking with the stop switch disconnected?

do you have an MSD enhancer?

1: no. will try. I figured since I have spark it was'nt the stop switch.
2: no. stock e-box

 

[SUPERTUNE]

Probably something wrong with the carbs and flooding after shutting off a hot engine and pressurized fuel system.

 

[FlightPlanDan]

Probably something wrong with the carbs and flooding after shutting off a hot engine and pressurized fuel system.

Supertune....I'm hoping, and I think you're right. I just got home from work and it fired right up. However, it's running VERY rich. Smoking like crazy. But I had to get it rinsed. Anyway it would not fire again after sitting for about 5 minutes. I believe it's flooding. Possibly needle not seating?

I'm gonna pull the carbs 1st. Clean, inspect, rebuild. I'll go electrical after that. But still open to ideas!

By the way, the crank seal must be O.K. if it fired......right?

 

[Aircraftsalz]

Time for a Xscream motor! SS827!



get it together, waves are looking good on Wed.