07 Apex won't start in cold after teardown

[slmz]

Hi Guys, Great Forum and thanks for all the help over the years with your knowledgeable tips and tricks. I've been having a problem with my Apex and after asking dozens of people, I'm turning to you guys for expertise.

So I've been a happy Apex owner for about 4 years and bought a low mileage ER. I was good up 'til last year when the driveshaft bearing seized and got worse until it took the speed sensor out. One morning trying to start it and got the deadly code 12, in mid season. End of season? Not around here, winters are looong. So instead of a quick fix I did a R/R on the whole sled replacing all worn bearings and parts. I used this forum of course and found help for lots of the tricky items including the code 12. On someone's post they suggested replacing the pickup coil before doing the complete stator. I got one off ebay and continued the rebuild. Got the sled all back together with a track extension and new track as well and voila no code 12. Sled runs great, take it for a few good runs. So all good right? unfortunately no. For some reason after all this it has become a wimp. It will not start in weather below about -15 degrees Celsius (5 degrees Fahrenheit). This is not the usual suspects, I will detail the steps I've tried. The only way I can get it started is by warming it up, specifically the engine area using a space heater and tarp. Starts fine in warm weather, runs good but after a cold night outside, no chance. not even once.

On Yamaha owners, dealers, mechanics, TY4Stroke Forums, google's suggestions I have:
- replaced plugs
- emptied fuel and run high octane
- Gotten a few different fuel relays ( even a red protoype ) and kept them warm in my pocket
- run isopropyl
- replace battery
- checked for shorts and ground-outs, removed any add-on wiring ( helmet shield heater, HIDs )

No other codes have come up.

You can hear the relay start with the key, I've tried waiting for it to prime and turning it over right away. The engine turns over fine, especially after replacing the battery. When it does start it sputs and stutters for the first 10-20 seconds and then idles up and purrs like it should.

My reliable Genesis has become unreliable and a thorn in my side since, I just wanna get this thing fixed so I can enjoy winter without having to worry if this thing will leave me stranded. Please Help!!!

Thank You for any help or feedback you guys give, fingers crossed on you being as helpful as you have in the past. Cheers!

Edit 1: It has good compression, checked while replacing plugs. The sled also has about 8500 kms on it (5300 miles)

 

[maxdlx]

Do a compression check

 

[steiner]

I would suspect the ebay pickup coil is not up to standards and when cold is giving the ECU faulty readings. When warm resistances change allowing the sled to start.

 

[slmz]

Thanks for the reply, the only reason I didn't buy the rotor assembly is the sticker shock ~$400. If that wasn't the problem, it'd be a kick in the wallet for no reason.

Anybody have experience with RMStator?

http://www.rmstator.com/en_ca/produ...1000-carb-lc-2004-2005-rx-1-carb-lc-2003-2005

 

[TBay Sledhead]

Did you get all the engine sensors plugged back in?

 

[slmz]

Did you get all the engine sensors plugged back in?

Yes as far as I know we did. It was checked several times and I did the plugs and re-checked the ecu and fuel system after it started acting up.

 

[Rich Kay]

After hearing it is temperature sensitive I wounder if it a sensor critical to start-up? say the coolant temp sensor or the air temp sensor? I would look at testing them. Should be able to check resistance numbers on them according to the shop manual.

 

[slmz]

Ok so here's my follow-up in the hopes I can help some other poor soul and return a favor granted to me once or twice on this forum. I replaced the cold air sensor in the air box - no change. I added the inline coolant heater which seemed to help at first but it just wouldn't start reliably when the sled was cold. I had a feeling it had something to do with the crank position sensor I replaced as part of the teardown, but didn't know what could be wrong with it ( it can't be adjusted because of the lip on the bolt holes for the mounting plate). I did some extensive googling and reading and came across this video.

It explains that there is simply not enough voltage at the sensor for the coils to fire. Soooo, I waited for a warm day and tore the cover back off the stator. I die-grinded the lips off the mounting plate for the sensor, drilled the bolt holes out and got it to mount a mm or so closer to the stator. The only bad part was there was no way to accurately measure the gap because of the magneto mounting to the case cover. The video suggests a very small gap so I figured it was worth the risk anyways ( worst case scenario, replace the magneto / sensor combo with OEM which I was close to doing anyways ). I got it back together and it started in half a crank! I of course let it warm up to overheating just to see if it would expand and hit the sensor but all looked good. I've driven it about 150 kms with no problems and it was starting nice. Today was the true test as I started it this morning at -30 c or - 22 f with no unusual start up problems and without the inline heater plugged in overnight.

There are lots of code 12 issues with 5+ year old apex's and I hope this fix will save someone some money and mid-season downtime and headaches.

Thanks again for a great forum and happy riding!

 

[trosell14843]

THANK YOU FOLLOW UP HERE IS HALF THE HELP!!!

Sent from my HTC6600LVW using Tapatalk

 

[thor452]

thanks for the update now when you start it cold do you still get the chug chug chug and then smooth idle after 30 seconds or so or is it just humming like a new sled when first started.

 

[slmz]

thanks for the update now when you start it cold do you still get the chug chug chug and then smooth idle after 30 seconds or so or is it just humming like a new sled when first started.

It doesn't chug anymore, it just purrs but it does stall a couple time if the first few seconds. It has always done that in the -30 temps and talking to apexer's, I understand it to be relatively normal. Maybe not?

 

[thor452]

hold key a second or two longer it will stay running. I wonder if the people with the chuging when first started are close to having a failure in the stator then??? huh lots of sleds that do that i wonder if this fix would cure that on stock ones??

 

[slmz]

hold key a second or two longer it will stay running. I wonder if the people with the chuging when first started are close to having a failure in the stator then??? huh lots of sleds that do that i wonder if this fix would cure that on stock ones??

All I can say for sure is, the video explains that substantial gap keeps the coils from firing ( or reliably ) which would make sense on the chugging. IMO the magneto and stator are well built solid parts so I would tend to believe the weakest link being the position sensor could be the cause of the problem. It is too bad there is no reliable way to check the sensor/magneto gap as I'm sure this widening gap over time can lead to issues related to code #12. You'd figure they could put an inspection port hole for it but those decisions are made above my pay-grade, lol.

Also I will now highly recommend the inline coolant heater for cold climates. This thing will save your battery and starter. Should be a stock option.

 

[apex55]

Any one doing the sensor change should measure the gap before removing the original. The RM that I put in 2 years ago stated you would have to open the holes to get it close enough.
Nice post.

 

[apex55]

Any one doing the sensor change should measure the gap before removing the original. The RM that I put in 2 years ago stated you would have to open the holes to get it close enough.
Nice post.