The Yamaha Road Star Warrior Forum

 Hey, been lurking around this forum for a while, hopefully I can get a few ideas.

 I have a 2005 Warrior, bought it a couple months ago used from a dealership with about 22,000 miles on it. Everything is great, with one exception. When I am riding on the highway around 70-80 mph, occasionally the motor will just cut out for a couple seconds. It doesn't die, it just starts slowing the bike drastically. After a second or two, it jumps back on, and away I go. I can't seem to figure out any pattern, except it only seems to to it when warmed up, never when I first take off or at night. I took it to the dealership, but they couldn't duplicate the problem, and I would prefer to fix it on my own anyway. Any ideas out there? It's driving me nuts, and nothing is scarier than losing throttle on the freeway in front of a semi.

Have your dealer run the serial # & see if the recalls have been completed for--------

Crank position sensor = CPS

Throttle position sensor = TPS

 I just got off the phone with the dealership, all the recalls have been done. Any other ideas?

+3 on CPS... does this occur when you roll on the throttle at about 3000 rpm?  Even if the recall on the CPS is done, it doesn't mean it has been done correctly or has not gone bad and require a new CPS....

 mdfd, yeah, it does happen around that rpm when i roll on. Has this happened to you? How difficult is a cps replacement?

 sounds alot like a CPS gone bad then...

The replacement procedure is not too difficult, just messy.  There is a CPS replacement kit that is for sale at the dealership.  It includes the new and improved CPS, new bolts, and  a new gasket for something like $35 or in that neighborhood.

Both AlanH and I have documented the process.  I know I have posted pics of each step as well.  Let me see if I can find it....

 Here you go:

Dragstar:

Before you crack open the engine to do a CPS, remove your battery and make sure there are no wires pinch under it.  I had several wires pinched and frayed under my battery causing my bike to stall.  I have heard of one other person having this happen.  I don't think it is really likely, and more likely it is the CPS, but it's free to check and fix.

always good advice..... (even though you're not really opening up the engine )

Mine was cutting out with a loose battery connection.   Hope its that easy.

 It reminds me of bad gas. Like it just completely shutsdown like no fuel and as you coast in a panic it suddenly rips to life.

Another could be CPS issue but I didnt think that the '05 was in the recall but I would have to go with bad gas (water) first.

elijiaht:

 I just got off the phone with the dealership, all the recalls have been done. Any other ideas?

Verify that the Dealer/installer of the new CPS part didn't splice the exiting wires to save labor. There are other components as well as an intermittent loose or grounded wire that can cause this type of failure.

A couple of members have replaced the LAS (Lean Angle Sensor) after replacing several CPS assemblies with similar symtoms of a failing CPS

IMO, there's no magic wand for this intermittent problem if a new CPS recall part was properly installed. In my particular case the failure was obvious as the black wire to the sensor was boken when i opened the case.

Reference: AkitaDog - Mon, Oct 20 2008 1:52 PM 
http://rswarrior.com/forums/p/121319/973289.aspx#973289

 My '05 was doing this exact thing and I had the CPS replaced twice on mine and it was a different type of engine cut out. The CPS had a definate rpm point that would react and cause the engine to run crappy. 

With the LAS it was very intermittent that I could go a day or two without it acting up. And itw ould only happen when cruising down the freeway at around 80 MPH. 

With hearing of this problem with another forum member I removed my LAS and opened it up and taped the swing weight so it would stay in the middle postion over the sensor on the circuit board. Well I'm conviced this was the problem, I have not had the engine shut down due the fule supply getting cut off. 

I'm currently having my local dealer check to see if this switch falls under the warranty and get a replacement.