Hardcore Sledder banner

1 - 20 of 30 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Got a 2003 Pro X 600 . It is popping at idle/ misfiring. It like somthing is turning spark of and back on again then it pops. Anyone know what causing this . Already checked throttle safety switch. It's not that. Thanks . Help ?
 

·
Premium Member
Joined
·
15,898 Posts
Got a 2003 Pro X 600 . It is popping at idle/ misfiring. It like somthing is turning spark of and back on again then it pops. Anyone know what causing this . Already checked throttle safety switch. It's not that. Thanks . Help ?
Probably running too lean. Clean carbs, especially pilot jets and their passageways. Then set air screws at around one turn open. Also, check for airleaks at carb boots, crank seals, fuel pump pulse hose, etc. Make sure there is no water in fuel and it's fresh. Synch carb slides so they rest at idle the same height and open equally when throttle is applied.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
Have done everything you said. New carb boots installed . Cleaned and installed new bellows on power valves. Seems electrical at this point bieng I've verified everything else. This sled is completely stock just as it was bought new. Thanks for your info and I am still on the quest to figure out the issue.
 

·
Premium Member
Joined
·
15,898 Posts
Have done everything you said. New carb boots installed . Cleaned and installed new bellows on power valves. Seems electrical at this point bieng I've verified everything else. This sled is completely stock just as it was bought new. Thanks for your info and I am still on the quest to figure out the issue.
I still believe it's too lean. Try briefly applying the choke at idle. Also try holding your hand over the mouths of each carb one at a time. If it smooths out, you need to look further for fuel system issues. Low fuel pressure? Bad reeds? Floats set too low? Needle/seats too small? Water trap hoses leaking on bottom of float bowls? To check for spark misfire, while idling, attach an inductive spark checker on exterior of plug wire and see if it shows misfire.
A timing light would work also.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #5
I will look more into the lean condition and try a timing light. I will let you know what I came up with. Thanks again.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
I still believe it's too lean. Try briefly applying the choke at idle. Also try holding your hand over the mouths of each carb one at a time. If it smooths out, you need to look further for fuel system issues. Low fuel pressure? Bad reeds? Floats set too low? Needle/seats too small? Water trap hoses leaking on bottom of float bowls? To check for spark misfire, while idling, attach an inductive spark checker on exterior of plug wire and see if it shows misfire.
A timing light would work also.
Did choke thing no . No change. Did timing light
 

·
Registered
Joined
·
40,076 Posts
Assuming your carbs are working properly, and not idling lean .
Make sure the temp sensor connection plug is clean or even replace the temp sensor.
Have you tried replacing the plug caps or cutting a small piece of the plug's wire's off if burn't
Degree the crank making sure it hasn't gone out of phase.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #10
Choke didn't cause it to flood a bit?
I slightly pulled choke and yes it richens It up but still pops. I cleaned carbs. Pulled every jet. It starts 2 puls cold. It idles solid like it always has except the popping thing. Can hear a miss when revved up and hold it it like 1/4 throttle. Gotta be electrical. This sled has been a screamer and always dependable. I raced a 2017 zr 600 last year it ran dead even with it. When i pulled it out this year I'm having this popping thing goin on. I did timing light and appears to be losing spark at the same time as popping thing. Seen on YouTube a new stator was required to fix. It's getting hard to get oem stuff.
 

·
Premium Member
Joined
·
15,898 Posts
I slightly pulled choke and yes it richens It up but still pops. I cleaned carbs. Pulled every jet. It starts 2 puls cold. It idles solid like it always has except the popping thing. Can hear a miss when revved up and hold it it like 1/4 throttle. Gotta be electrical. This sled has been a screamer and always dependable. I raced a 2017 zr 600 last year it ran dead even with it. When i pulled it out this year I'm having this popping thing goin on. I did timing light and appears to be losing spark at the same time as popping thing. Seen on YouTube a new stator was required to fix. It's getting hard to get oem stuff.
Take a close look at the trigger coil inside the stator housing mounted usually right on the stator plate but triggers off the metal plates on outside of flywheel. If bent too far away from flywheel, it can cause misfire. Also, check that metal plates are not loose or damaged. Make sure flywheel isn't loose on crankshaft or wobbling.
See rectangular box screwed to side of stator in pic.
 

·
Registered
Joined
·
6,163 Posts
It sure sounds like a twisted crank. I see a LOT of those.If it ever flooded with gas and you tried to start it the crank is twisted.Check your crank phase before buying a bunch of electrical parts.
 

·
Registered
Joined
·
147 Posts
I slightly pulled choke and yes it richens It up but still pops. I cleaned carbs. Pulled every jet. It starts 2 puls cold. It idles solid like it always has except the popping thing. Can hear a miss when revved up and hold it it like 1/4 throttle. Gotta be electrical. This sled has been a screamer and always dependable. I raced a 2017 zr 600 last year it ran dead even with it. When i pulled it out this year I'm having this popping thing goin on. I did timing light and appears to be losing spark at the same time as popping thing. Seen on YouTube a new stator was required to fix. It's getting hard to get oem stuff.
Ricks Motorsports electrics in NH has a stator for that if the OEM one is discontinued.
 

·
Registered
Joined
·
40,076 Posts
It sure sounds like a twisted crank. I see a LOT of those.If it ever flooded with gas and you tried to start it the crank is twisted.Check your crank phase before buying a bunch of electrical parts.
I agree, didn't want to say it. We had a liberty 600 carb sled here not long ago that just didn't run right with a constant misfire in it. Checked everything. Finally degreed the crank...that was the issue.
 

·
Premium Member
Joined
·
15,898 Posts
I agree, didn't want to say it. We had a liberty 600 carb sled here not long ago that just didn't run right with a constant misfire in it. Checked everything. Finally degreed the crank...that was the issue.
Crank degree quick check should only take 5 minutes. One piston at TDC the other at BDC using a simple screw driver placed in the spark plug holes. No need for a degree wheel, etc.
 

·
Registered
Joined
·
16,827 Posts
my 99 xc700 started misfiring, not too bad at idle, worse from 3-5 5k, above that it cleared out. found it to be a sheared flywheel key.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #17
Assuming your carbs are working properly, and not idling lean .
Make sure the temp sensor connection plug is clean or even replace the temp sensor.
Have you tried replacing the plug caps or cutting a small piece of the plug's wire's off if burn't
Degree the crank making sure it hasn't gone out of phase.
Have replaced temp sensor a few years back because it failed. How do I check crank to make sure it's not out of phase ? I'm going to start replacing electrical stuff. Start with secondary coil and new reeds. If that does not make a diff then going to stator. I feel the motor is fine. There is a failure of electrical component some where. Been wrenching on sleds along time but nothing this new. Lol yet it's old. Most of my experience is with 1980 and older sleds. Alot of technology on this sled I have not delt with but it's my time to learn forcefully. Love this sled and determined it will live. I will not stop till I figure it out. Thanks for the input. I am far from knowing it all but very capable so I so much appreciate every bit of advice I can get. 😁
It sure sounds like a twisted crank. I see a LOT of those.If it ever flooded with gas and you tried to start it the crank is twisted.Check your crank phase before buying a bunch of electrical parts.
You know when I pulled it out of storage one of the needle was stuck and filled crank with fuel. I did try to start but it never really fired or back fired cause I seen gas coming out of y pipe and knew what was up and went to the carbs. Well maybe I just head to the bench with the motor and start at ground zero. Damn Really dont feel that's it but never know till ya go there. T Y for advise.
my 99 xc700 started misfiring, not too bad at idle, worse from 3-5 5k, above that it cleared out. found it to be a sheared flywheel key.
I will check that. Dont usually see that on snowmobile engines. Thanks for the advice very much.
 

·
Premium Member
Joined
·
15,898 Posts
Have replaced temp sensor a few years back because it failed. How do I check crank to make sure it's not out of phase ? I'm going to start replacing electrical stuff. Start with secondary coil and new reeds. If that does not make a diff then going to stator. I feel the motor is fine. There is a failure of electrical component some where. Been wrenching on sleds along time but nothing this new. Lol yet it's old. Most of my experience is with 1980 and older sleds. Alot of technology on this sled I have not delt with but it's my time to learn forcefully. Love this sled and determined it will live. I will not stop till I figure it out. Thanks for the input. I am far from knowing it all but very capable so I so much appreciate every bit of advice I can get. 😁

You know when I pulled it out of storage one of the needle was stuck and filled crank with fuel. I did try to start but it never really fired or back fired cause I seen gas coming out of y pipe and knew what was up and went to the carbs. Well maybe I just head to the bench with the motor and start at ground zero. Damn Really dont feel that's it but never know till ya go there. T Y for advise.

I will check that. Dont usually see that on snowmobile engines. Thanks for the advice very much.
See my post #15. That method is a quick check without a degree wheel. You can get much more accuracy by using a dial indicator inserted into the spark plug hole and a pointer or fixed position on the block near the primary clutch. Set one piston on exact TDC, mark the outer diameter of inner sheave of the primary in line with pointer. Move dial indicator to second cylinder. Rotate crank till that cylinder is at TDC. Mark a second mark on the outer diameter of the primary inner sheave. Measure the distance between the two marks in both directions. It should be exactly the same or very close.
 

·
Registered
Joined
·
16,827 Posts
How do I check crank to make sure it's not out of phase ?
got a dial indicator?

havent tested phase myself but got told to find tdc on both cyls and mark the primary correspondingly. Then measure around the circumference to see if distance between marks are the same both ways. oops I see Phil beat me to it :)
 

·
Registered
Joined
·
14 Posts
Discussion Starter #20
See my post #15. That method is a quick check without a degree wheel. You can get much more accuracy by using a dial indicator inserted into the spark plug hole and a pointer or fixed position on the block near the primary clutch. Set one piston on exact TDC, mark the outer diameter of inner sheave of the primary in line with pointer. Move dial indicator to second cylinder. Rotate crank till that cylinder is at TDC. Mark a second mark on the outer diameter of the primary inner sheave. Measure the distance between the two marks in both directions. It should be exactly the same or very close.
Ok makes sense. I have the indicator set up. I'm on it. I will let you Know what it shows.
 
1 - 20 of 30 Posts
Top