Help with strange problem

[vmxrdr]

Finally got a good rip in with a few buddies down to Shelburne Ontario from our home base of Owen Sound. My sons sidewinder developed a strange issue that has us scratching our heads on the ride though. Its a 17 with TD MS17, superquiet muffler, aftermarket fuel pump and manual pressure adjuster. Sled has never missed a beat in 18,000 kms. It has started to miss or sputter in upper rev range and under hard acceleration but only when fully heat soaked. Until its been ran quite a while to be fully hot it works perfectly. We have checked fuel pressure at 42.5. We have swapped ignition coils out with new ones already because my Audis over the years had same symptoms from crap ignition coils, to no avail didnt change anything. Swapped fuel pump with my winder already too, no difference. Any input would be greatly appreciated, we finally have trails and now this happens.

 

[KnappAttack]

Change the spark plugs.

I'm going to ask if you use octane booster in it at all? Reason I ask is some (most) of the boosters contain MMT and I think the MMT can cause issues with the plugs.

I believe plugs should be changed ever season if you use booster that contains MMT to prevent fouling.

 

[sideshowBob]

Change the spark plugs.

I'm going to ask if you use octane booster in it at all? Reason I ask is some (most) of the boosters contain MMT and I think the MMT can cause issues with the plugs.

I believe plugs should be changed ever season if you use booster that contains MMT to prevent fouling.

Plugs were my first thought as well.

 

[74Nitro]

Could it be that the gap is slightly too big on the spark plugs. That can cause misfire on boosted sleds.

 

[74Nitro]

Hey, 18000kms and max 17, how about some feedback on clutch? Holding up or running something else.

 

[vmxrdr]

Thanks guys, I checked with my son and he had put plugs in last spring because he thought the issue was starting then. It wasn’t near as obvious then he says. Might try another set. As far as clutch goes nytro sled has a hurricane 1.75” and he beats on it hard, it still works okay but chews up primary rollers bad so we are going to put an apex primary on it on Knapp’s advice. Should we try a different plug maybe? When the water pump impellers fail on these what are the symptoms?

 

[KnappAttack]

Thanks guys, I checked with my son and he had put plugs in last spring because he thought the issue was starting then. It wasn’t near as obvious then he says. Might try another set. As far as clutch goes nytro sled has a hurricane 1.75” and he beats on it hard, it still works okay but chews up primary rollers bad so we are going to put an apex primary on it on Knapp’s advice. Should we try a different plug maybe? When the water pump impellers fail on these what are the symptoms?

You should gap the plugs down .022" or .020" in that range if you suspect it's missing. I'm using CR9EK dual ground strap plugs and lowering the gap to .022", but I change them every season because I've been using MMT octane boosters which puts that gold dust on them and makes them look funky. I'm now going to try Klotz higher octane booster and see if the plugs look better without the MMT in the octane booster.

If the water pump fails it will quit pumping water and overheat.

 

[Turboflash]

Thanks guys, I checked with my son and he had put plugs in last spring because he thought the issue was starting then. It wasn’t near as obvious then he says. Might try another set. As far as clutch goes nytro sled has a hurricane 1.75” and he beats on it hard, it still works okay but chews up primary rollers bad so we are going to put an apex primary on it on Knapp’s advice. Should we try a different plug maybe? When the water pump impellers fail on these what are the symptoms?

You'll know when it fails, overheat in 5-10 seconds. Temp from 168 degF to over 200 on less than 10 secs. Happened to mine Friday afternoon. Cheap China plastic impeller came loose from shaft.

 

[vmxrdr]

I think we will order a water pump to put on shelf. More testing yesterday, double checked gap in new 9EK plugs and after a 45 minute run it still did it. Honestly feels like its getting into rev limiter but its doing it at 7600 to 8000. If you let it cool off even for a few minutes it pulls like a scalded cat again. May try swapping ecus with an 18 today but the problem started last ride in spring and sled has since been reflashed to closed loop tune which we are still waiting on sensors for. Being that it started before reflash not hopeful thats problem.

 

[74Nitro]

Check the resistance of the pickup coil when heat soaked and compare it to spec, or another machine.

 

[vmxrdr]

Shout out to Ben at TD. My son got talking to him and he mentioned there could be moisture in the tube to the map sensor that could cause my sons symptoms. Blew out line and swapped a map sensor from 18 and problem solved. Going to swap sensors again just to be sure in case we need to order a new sensor

 

[Slow998]

Shout out to Ben at TD. My son got talking to him and he mentioned there could be moisture in the tube to the map sensor that could cause my sons symptoms. Blew out line and swapped a map sensor from 18 and problem solved. Going to swap sensors again just to be sure in case we need to order a new sensor

Was it just moisture in the line? Or did it end up needing a map sensor?

 

[Fleecer]

You'll know when it fails, overheat in 5-10 seconds. Temp from 168 degF to over 200 on less than 10 secs. Happened to mine Friday
afternoon. Cheap China plastic impeller came loose from shaft.

TF, how many miles. Will you replace with OEM, or aftermarket billet???

 

[Turboflash]

Checking out both SpeedSXS kit ($499 US) (https://speedsxs.com/products/wildcat-xx-and-tracker-xtr-1000-billet-water-pump) and Dasa Racing impeller ($249 US) (https://www.dasaracing.com/product-p/xx-wpim.htm). Dasa told me yesterday they are on revision 5 now. Changed shaft material and the way the impeller mounts to shaft. Trying to get an answer but I believe the impeller is now threaded onto shaft, no more cross holes.
Remember if one chooses the Dasa impeller, most likely you'll end up buying another $100 worth of parts (o rings, seals) to do job right.
SpeedSXS kit already contains all that. It's complete kit with everything needed.
As soon as Dasa answers my questions I'll make my decision. Don't have snow here in southern MN anyway so not in a hurry to get it going.

 

[02ViperMody44]

Checking out both SpeedSXS kit ($499 US) (https://speedsxs.com/products/wildcat-xx-and-tracker-xtr-1000-billet-water-pump) and Dasa Racing impeller ($249 US) (https://www.dasaracing.com/product-p/xx-wpim.htm). Dasa told me yesterday they are on revision 5 now. Changed shaft material and the way the impeller mounts to shaft. Trying to get an answer but I believe the impeller is now threaded onto shaft, no more cross holes.
Remember if one chooses the Dasa impeller, most likely you'll end up buying another $100 worth of parts (o rings, seals) to do job right.
SpeedSXS kit already contains all that. It's complete kit with everything needed.
As soon as Dasa answers my questions I'll make my decision. Don't have snow here in southern MN anyway so not in a hurry to get it going.

What year sled, how many miles? Ever overheat the sled prior where it went into limp mode? Just curious. My sled seemed to run hot last season and went into limp mode a couple of times, hoping it doesn't shorten the life of that cheap impellor!