Engine spluttering

[ausimoto]

Hi guys

Just wondering if anyone has had a problem with the engine coughing and spluttering at full throttle.

The reason i ask this is because i went out riding with a mate yesterday on his 2005 RMZ450 where it still has awesome power but when you hit full throttle the motor seems to breakdown.

Your assistance would be appreciated.

ausi

[TyDog]

Ausimoto,

Is this right after you fully open the throttle and the engine is trying to build revs or after it has reached the upper parts it's rev range? Sorry to be nosey, I just do not fully understand the problem.

TyDog

[bazuki54]

My 06 was missing from mid to top and it turned out to be the stator. I guess from washing it, water got in the wire housing and shorted it out. I went through every thing. I swaped out every electrical part and the last thing I checked was the stator/magneto. It was very expensive ($230).

[ausimoto]

Tydog

It is the upper parts of the rev range where the motot is spluttering.

hope this helps.

ausi

[TyDog]

It could very well be the stator but I would try the obvious and less expensive routes first.

If it is popping, blubbering and missing violently like that, I would look for an air leak between the carb and the engine causing it to go lean. That definitely is not good!!! Could try the spark plug but I just do not think that is the problem.

If it just wants to lose power and bog, I would check the air filter for being clogged and the cleanlinees inside the carb. I would mainly be looking at the main jet crcuit. One other one along this route would be the fuel strainer in the fuel tank for being clogged. I have seen one these clog (not on a RMZ though) and the bike will run fine until until it really is trying to draw a lot fuel on top end with a load on the engine. It was drawing the bowl dry after extended long runs.

I hope this is of some help help to you. Please reply back good or bad news, cool?

Anybody else offer any ideas?? Eddie.

TyDog

[zshredder]

I am having this same problem with my 2005. It seems to happen when I am acclerating hard out of corners and it just starts bogging in the mid to top. It has scared me a couple times by almost throwing me over the bars. It does not seem to happen when I roll on the throttle and then hold it wide open?

[DL126]

Check out your needle and needle jet guys.

Weird things can happen when those get worn.

Mine got to the point where it ran like a 2 stroke because of that.

Bog on bottom .... then hit like crazy when the main took over.

Just a thought.

[MCrider87]

I would look into the strainer in the fuel tank. I had the same problem and cleaned my carb numerous times before i finally figured out that it was clogged. I hope this helps!