Hi,

I also have a 05' 450R and it's actually giving me some issues as well. I love it however, this past weekend I had to get towed out of the woods. I was riding all day and I noticed it wasn't running as hard as it normally does. After a few hours of riding it started acting up. It was bogging out and backfired a couple of times. I checked the plug, cleaned the already clean airfilter, pulled the carb and cleaned it inside and out. I went through all of the wiring harnesses and checked them out. I put the bike back together and it ran like a champ for about 10 minutes. After about 10 minutes of hard riding the bike began to act up and do the same thing... Bog out.. I thought it might be related to the temperature... I checked the fan and it's working. I checked the wire running to the coil and their okay.

I touched the CDI box and it was hot. Is the box supposed to get hot? I'm reaching at this point. Any ideas? I did the above recomendation and change the air fuel ratio and still no luck. I'm completely lost with this one.. I'm trying to avoid taking it to the dealer because I'm sure they're not going to recreate the problem testing the bike out in the parking lot. The bike runs perfect for a few minutes and then starts acting up.... Any other ideas you can offer would be greatly appreciated.

Thanks!

 

Don't touch the air/fuel screw yet. They made it tough to adjust for a reason. They don't want you to adust it in general. Start off by adjusting the idle up a little (the **** under your right frame rail above your motor.) Hopefully, you have read your owners manual and already know where this **** is at.

1. Adjust up the idle a little first.
2. When you push the throttle on this carb STOCK, you may have to push it a little bit smoother than you might other throttles.
3. I'm not sure what bikes or quads you have owned in the past but this one is meant to be reved up a bit as you let out the clutch.

Based on what you are saying it is not necessary to adjust your air/fuel screw, unless it idling ruff.

Let us know what this helps!

 

You need to tell us the whole history of this quad and all mods from stock.

 

Try loosening the gas cap when it acts up or instead of riding it, simply blow into the vent hose and see if the air is going into the tank. The cap is supposed to be vented to prevent vacuum in the tank. Maybe the vent hose is clogged. Not sure about the hot CDI but it is possible that they are supposed to get hot.

 

Hi, thanks for the reply.

I'm running the quad all stock. I bought the quad last January. Since I bought it I've put about 50 hours on it. I did the valves at 25 hours. I change the oil and filter after every 4th ride (About every 12 hours riding). The bike has been great with no problems whatsoever until this past weekend. I do ride it hard and jump alot with it but I don't think it's anything the bike can't handle.

I tried to blow into the vent hose and it's A.O.K. Do you think this can be a valve issue perhaps? I'm puzzled because I also have a 400 and when I needed to do the valves it wouldn't even start. My 450 starts without a problem as long as it's cool.. Then when I ride it for a few minutes it acts up.. But it starts.. I just can't get it to go. It dies when I release the clutch in first after an "Episode." I did check the fluids and they're okay. I also checked the fan last night to see if it's turing on when it's supposed to. All of the electrical components appear to be okay.. Any other ideas?? Does this sound like a valve symptom? As you can see, I'm trying my best to avoid having to open the motor...

Julian

 

It sounds like a spark issue but if you suspect the valves, a compression test is all you need to be sure.
Otherwise you can check for spark by removing the plug and while holding it against the head, crank the engine over. Should be a cracking blue spark every 180 degrees of crank rotation.

 

Thanks for the suggestion. I'll check the spark tonight when I get in.. I don't have the compression checker tool so I'll save that for the last resort (Dealer Visit). [img]i/expressions/face-icon-small-smile.gif[/img]

 

Well I'm not exactly how this post turned into sovleing two different problems but it seems that the problem that I have with the stalling only when I snap the throttle is better after turning up the idle to about 1800 rpms.The manual says 1700+or- 100. I was also able to make the tool to adjust the mixture screw. I turned that one half turn out and turned it back after it did not seem to help. I turned the idle stop screw about 1/2 turn up.
Dunefool you might be right. I have a 400EX and a 250EX and I might just have to change my style of riding when I'm on my 450. But on the other hand I don't think it should stall when I'm in neutral and just snapping the throttle part way. I rode the bike tonight for about 1 hour and it didn't stall on me but I also was not snapping the throtle like I was Sunday. The trails where really tight and I was on and off the throttle a lot. The trails I test on tonight where more open and less throttle demanding. Anyways I will keep you guys posted if I have anymore trouble. Thank-you very much to the guys that helped with my problem. Any other commets or suggestions are welcomed.

 

Hello Rise400ex.. I saw your thread and thought we were experiencing the same issues.. Didn't mean to step on your toes..

So I did the compression test and it's pushing just under 40 psi. This appears to be low. Any idea of what the meter should read? I think I'm going to take it to the dealer.... Any more ideas or suggestions? I appreciate your time.

 

The 450R has a compression release that will have an effect on your reading but 40 psi sounds way too low. Check your valves and your compression release rocker. Its ease to do.