Occasional Stalling

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who_gives_a6 · #1 Post by **who_gives_a6** » Fri Dec 16, 2011 7:08 pm

Took a quad to the track today. Planned on racing a GP race tomorrow. Ran great for two laps and started great, even with 40 degree weather. Then it started to occasionally hesitate on full throttle 3rd/4th gears. And the last lap out the quad died three times in one lap. All full throttle 3rd/4th gear. Seemed fine until it got hot.

Running ported 467 with Trinium map, Cyclone intake, gutted disconnects, g12 filter brand new. Was going to play with settings maybe but computer crapped out and on phone still here. Any suggestions to cure or just load up and fix at home? Map injector/flowrate suggestions? I believe its at around 1700 and .88 now which is preset. When its only slow ridden its phenomenal. Only when hot the issue arises.

cannondale27 · #2 Post by **cannondale27** » Fri Dec 16, 2011 10:05 pm

Do a compression test while its hot.Valves tight.Second guess would be a bad stator or coil.

speedracer · #3 Post by **speedracer** » Fri Dec 16, 2011 10:57 pm

What about the relay in the ecu tray?Doesnt cold temps make it act up?

who_gives_a6 · #4 Post by **who_gives_a6** » Fri Dec 16, 2011 11:56 pm

As an update: I screwed up the first post. Its when I let off after a full throttle sometimes. I can hammer the throttle to hit a jump, even get on the throttle in the air and it's fine. I hit the ground and then it bogs and dies a few seconds later. I stop and hit the starter and it fires right up.

Thinking maybe electrical or coil. I ran probably 20-25 laps after this post and had 4-5 more stalls. Seemed to get better as it went along. Just got home and checked settings and it's on 1700 and .90. Throttle recal was done before going and also has ported throttle body.

The thing just rips. Cleared a massive jump first time out on it that only a couple bikes would hit. And the cyclone just sounds crazy, lol. Got some pics I'll try to upload later.

The relay also may make sense. As it warmed up to around 60 or so it calmed down. When it dies it'll fall on it's face and you can't let momentum restart or hit throttle. I had to stop and restart each time.

cannondale27 · #5 Post by **cannondale27** » Sat Dec 17, 2011 3:59 am

A status light really helps in these situations.If the light goes out before the stall its 100% sure electrical.

MX Quad Dad · #6 Post by **MX Quad Dad** » Sat Dec 17, 2011 1:26 pm

If it stalls it will not re-fire until ecu is reenergized. Because I have not had problems with my neutral safety switch I left in alone and if I do stall it I can just tap the starter button while still rolling and she will re-fire. I think you risk hurting the one way bearing without the safety switch to disable the the starter but imagine you could rig up a second button for this, would need a diode or something. I really don't understand the reason for this time-out function and would somebody be able to disable it?

If you are only stalling on impact from landing It could be a bad connection or that relay. When I was told about the ground problems I went thru and checked all the ground points and the one I didn't like was where they attach to the frame at the pressure regulator. so I put a longer bolt in so I could put a nut on it with the star washers so the wires are tight to the frame before the regulator is installed. those crimp lock nuts bothered me so I ran a jumper wire between all ground points and even one to the motor. I never had a problem before or after I did this to the Moto but, ran into a stalling problem with my Speed and a little tightening of the regulator hold down bolts made it go away so, it got the same as the Moto

wistech · #7 Post by **wistech** » Sat Dec 17, 2011 3:44 pm

Stalling while riding I doubt would be a mapping issue.
Common stalling problems with a quick restart would be
Ground or battery connections.( Like Dad says run a bolt through )
That darned relay ( just remove it)
Fuel pump terminals wires loose. ( unplug the connector before cleaning or tightening)
The ignition coil has gone bad (it will short out internally when hot)
Flywheel coming apart/spinning or flywheel hitting stator and grounding it out. (could be a crank bearing so a filter check would be in order) If the bearing is gone it will mess up the crank signals due to gap changes.

Engine kill buttons or pingle switch unscrewing.

svahle · #8 Post by **svahle** » Mon Dec 19, 2011 1:54 pm

I had this problem on my Moto. The ECU was shutting down. Like others have said, I went through the ground contacts. I took steel wool to all the contact points and retightened everything. Until I had time to do this, I learned if it died to just tap the start button to restart while rolling.