I put on the Q4 a month and a half ago. I expected it to become lean, but I didn't notice much more heat coming off it. A bit more, but acceptable IMO. So I left it as-is. I have an EFI bike, so not much I could do without a fuel controller anyway, right?

I've ridden it like this since then - not an every day thing, more like every 4 or 5 days.

Somewhere along the line I thought since it's a bit hotter, I should put the stock snorkel back on. Maybe that would limit the air intake somewhat. Figured it wouldn't hurt. Rode a 200 mile day trip a couple weeks ago and all was good. Only road riding.

Yesterday I took it to the mountains off-road. Lots of hill climbs, pushing her somewhat hard. Towards the end of the ride I was creeping along and she overheated and shut down. Waited a while, and it started and got me home no problem.

Today I rode it in the city and it got really hot. Stalled at two lights and the overheating light came on. It was backfiring between the first two shifts almost like clockwork. Also sometimes on deceleration. It was kinda sputtery/jumpy/not smooth in first and second at lower RPM's. Higher RPM's it ran well.

Oil is at the proper level.

So...obviously lean and I need to get a fuel controller. But...what I'm wondering is why now? Over a month and no problem and "suddenly" it decides it wants to overheat.

Is there another problem popping its head up or does a lean condition slowly "build up" so to speak?

 

Sounds like maybe just a particularly hot day and city traffic, but it could be something else. I am not a fan...no pun intended...of the fan operation temp setting from the factory. IMO it's too high, and by that time heat soaking has built up to a level that can be hard to manage. I use a Trail Tech Vapor instrument panel on my '06 model, so I can see the actual digital temp reading degree by degree, and I can set the yellow and red warning lights at the temps I want to be notified. I installed a manual fan switch, and I turn it on during any extended climbs or other hard, off road situations that tend to push the temps up. I usually turn it on at about 195 degrees, and I can push as hard as I want without the bike going past 200 degrees. Now, these bikes can run pretty hot without damage or problems, but I don't think it's ideal for engine longevity or performance when you really need to continue to push the bike hard.

 

A week after I put on my q4 my fan turned on while climbing and it started backfiring. Turned out the bolts to the header weren't properly tight. I would check there first!

 

Yeah, I think you're right. It was pretty hot that day. Coupled with city driving might have made the already slightly overheated engine go over the edge.

My EJK arrived the other day and I gotta say it's freakin awesome! Installs in minutes and one 30 min ride later and my bike is running perfectly! Can't complain

 

Does the rad fan work?

 

That was one of my first thoughts. Checked the fuse first and it was good. Then turned it on and let it run to make sure it would kick in. It does, but like TNC said, it kicks in too late.

With the weather the way it is here, I might just put in a manual switch. Maybe a stronger fan too. Stop lights are murder!