06 Attak stalling at idle

[attak65]

Hi to all members on this site. First time 4 stroke owner. I just purchases a 2006 attak with 6000 miles on it that had an idle problem when I bought the sled, stalls sometimes when I let off the throttle. I removed the IAC and cleaned it and replaced the plugs. I checked the coils also and they are within spec. I checked the vacuum in cyl 1,3,4 have 7" HG and cyl 2 has 13" hg. I also checked the compression cyl 1=165, cyl 2=182, cyl 3=182, cyl 4=178 . Something is out of whack enough that I cant even begin to adjust the four screws on the IAC for the throttle body sync. Also I can shoot a small shot of carb cleaner into the individual throttle bores 1,3,4 and the rpm drop dramatically but on cyl 2 that has the higher vacuum I can give it a shot of carb cleaner, and it has absolutely no effect on the rpms. I also stuck a different IAC valve on there and got the same results.
I am at a total loss here, Is it possible that the ECU is throwing the spark timing off to the #2 cyl so its not firing at the right time ? Any suggestions would be greatly appreciated.
I know this seems to be a broken record from all the reading I did on the web last year. With 6000 mi I hope its not a valve adjustment problem.


Thanks

 

[sideshowBob]

Lots of info on this if you do a search. Typically the cure has been to get the valves adjusted.

 

[74Nitro]

Use a leakdown tester. They are far superior to a compression tester. A leakdown tester will let you know where pressure is being lost.

 

[kinger]

Also have you checked the vacumn lines? Small pin holes have found mine before and it wasn't until I just replaced the whole nest with a used set on Ebay that I noticed one had a pinhole leak. Fixed all my erratic idling that I thought was from the MPI supercharger controller messing with the fuel.

https://ty4stroke.com/threads/08-ap...r-low-rpm-miss-rough-idle.162224/post-1551327

 

[attak65]

Thanks for the ideas. I did buy a used throttle body off of ebay and put it on there with all new hoses and that didn't help either. I know you can adjust the TPS by looking at the instrument cluster or the manual also says to adjust the position use a voltmeter .63 to .73 volts. does one way to adjust work better than the other?
I know this subject has been beat like a dead horse already.
Thanks

 

[mbarryracing]

When the valves (intake or exhaust) get tight and are in need of adjustment, it affects the intake pulses to the MAP sensor and causes all sorts of running gremlins...
Check your clearances.

 

[attak65]

I went out last night and experimented with it again and it would run and idle perfect when I was riding, If I let off the throttle gently.
If I slammed it shut that is when it would stall or idle down to 600 or 700 and stumble and almost stall. If it was a valve adjustment problem would it do it all the time once warmed up?
Thanks again for everyone that is pooling their knowledge.

 

[kimoajaj]

My first post on the forum in a while!
Considering to buy an Apex Warrior 2006 with the same milage, and I would never expect the valves to be out of adjustment on a Yamaha at that milage! But I have been out of the Apex game for 15 years so little do I know.. .

As mentioned above, a vaccum leak will mess things up. Lot`s of experience with that on some Nytro`s.

 

[attak65]

My first post on the forum in a while!
Considering to buy an Apex Warrior 2006 with the same milage, and I would never expect the valves to be out of adjustment on a Yamaha at that milage! But I have been out of the Apex game for 15 years so little do I know.. .

As mentioned above, a vaccum leak will mess things up. Lot`s of experience with that on some Nytro`s.

I thought so to, but I changed all of the vacuum lines on the throttle body and IAC valve already and it made no difference. The voltage range for the TPS looks like a very fussy adjustment that I have not checked yet with a meter. TPS sensor- book says fully closed 15 to 18 and fully open 95 to 100. Mine said on the diag display 17 closed and 97 open. The book also says to adjust the TPS angle until you get between .63 and .73 volts.
Does anyone have any experience adjusting one way vs the other?

 

[Oldvolts]

I had this same problem on my 2007 Attak. Adjusting the fuel CO helped quite a bit, but I can still stall it.

STALLING CURE!!!

First of all I did not find the cure myself. got pointers and help from FABIO. All I had to do is set the CO on all injectors to -10. This is verry easy to do. All you need is a little wire and it can be set using your gauge cluster.

ty4stroke.com

 

[SugarCampApex]

I had the same symptoms on my Apex (15K miles) and did all of the posted adjustment tips but it would stall out. Deep down I knew that it probably needed a valve adjustment. I had Mr Sled do a valve adjustment and it runs like new!

 

[RobX-1]

Although I would agree needing a valve adjustment after 15,000 miles is acceptable, I wouldn't think that would be the case on one with 6000 miles. Heck, my 08 Apex has over 19,000 miles and still runs like a champ. Between the two Apex's I own, she is by far the runner of the two.
Even Rock rode it last year and stated that if his old Apex ran as good as mine, he would have never sold his.

 

[sideshowBob]

If my memory is correct...there was at least one update on the early Apexs TPS as well as their stators. A new TPS may be worth a try.

 

[sideshowBob]

Although I would agree needing a valve adjustment after 15,000 miles is acceptable, I wouldn't think that would be the case on one with 6000 miles. Heck, my 08 Apex has over 19,000 miles and still runs like a champ. Between the two Apex's I own, she is by far the runner of the two.
Even Rock rode it last year and stated that if his old Apex ran as good as mine, he would have never sold his.

I am always suspicious of mileage on a used sled...very easy to sway speedo heads on the Apexs.

 

[attak65]

I guess I never considered the possibility of incorrect milage. Is there any way to tell ?