[Mailman]

Calling all 4 stroke gurus. I have a 2005 Honda TRX450R with some mild mods; Venon pipe, 182 main, hrc needle, air box cover removed, K+N stock replacement filter.

The bike ran great last season for 5 or more trips. It sat for 4 or 5 months in the off season and now I have this condition.

It starts, idles and runs fine in the lower rpms. It cuts out or misses in the higher rpms like it has a false lower rev limiter. It doesn't matter if the bike is under load or not.



I tore apart the carb and cleaned the jets but no help. I swapped parts with another bike and tried the "black box" and the coil but no change. You can actually hear the bike cutting out if you try to rev it up in neutral. If I had to guess, then I would say it is cutting out around 7000 rpm but tha is just a guess.



I am thinking about checking the carb again and thought the "air jets or passages" might be clogged causing a rich condition. Outside of that, I was just going to go through the rest of the electrical system. It is an '05 so it has the older carb (NOT FCR).



Anyone have this happen to them??? Any help is greatly appreciated.





Mailman

 

[travis fulton]

Calling all 4 stroke gurus. I have a 2005 Honda TRX450R with some mild mods; Venon pipe, 182 main, hrc needle, air box cover removed, K+N stock replacement filter.

The bike ran great last season for 5 or more trips. It sat for 4 or 5 months in the off season and now I have this condition.

It starts, idles and runs fine in the lower rpms. It cuts out or misses in the higher rpms like it has a false lower rev limiter. It doesn't matter if the bike is under load or not.



I tore apart the carb and cleaned the jets but no help. I swapped parts with another bike and tried the "black box" and the coil but no change. You can actually hear the bike cutting out if you try to rev it up in neutral. If I had to guess, then I would say it is cutting out around 7000 rpm but tha is just a guess.



I am thinking about checking the carb again and thought the "air jets or passages" might be clogged causing a rich condition. Outside of that, I was just going to go through the rest of the electrical system. It is an '05 so it has the older carb (NOT FCR).



Anyone have this happen to them??? Any help is greatly appreciated.





Mailman

try jetting 1st!!!!!!!!!!!! and if that dosent help,(sounds like jetting to me) try cking the stator,

 

[T-Rex]

Go down to a 180mj or even a 178mj that should take care of your issues.

 

[Radar]

Without it being under a load if it does it with no load I woulda guessed electrical prob. Since it ran fine and now it cuts out I woulda said check ground to stator, coil etc. Does it have any kind of throttle over ride/ wires to carb? Just messed with a bike for 5 hrs till we fixt the throttle pos sensor.

 

[Mailman]

Without it being under a load if it does it with no load I woulda guessed electrical prob. Since it ran fine and now it cuts out I woulda said check ground to stator, coil etc. Does it have any kind of throttle over ride/ wires to carb? Just messed with a bike for 5 hrs till we fixt the throttle pos sensor.

Hey Radar,

What were the symptoms with a bad tps? I checked the tps with the ohm meter and it seemed fine. I unplugged it though and the bike ran the same.



Mailman



ps. The bike cuts out at a low throttle setting but high rpms in nuetral so I don't think it would be the main. Besides, the main was great for a whole season and now it is too rich. That doesn't make sense.

What is the easiest way to check a stator on the 450R? I ran the ohm test on the 3 yellow wire plug and it read fine. I know this is no guarantee though.

 

[T-Rex]

Trust me go down on the main jet.. I am almost positive your problem will go away. If not my bad!



A dirty air filter will give you a rich condition..

 

[Mailman]

Trust me go down on the main jet.. I am almost positive your problem will go away. If not my bad!



A dirty air filter will give you a rich condition..

I appreciate the help but the filter is clean. I even removed the filter to see if that was the cause. No change.

I would try the jet but the bike does it in nuetral when I try to hold the throttle about a quater open just to raise the rpms; that is when it starts missing and blowing a little black smoke. I don't think the main is even being used for this low of a throttle setting. I also don't know why this jet worked great for a whole season and now it is just too rich.

I really think it is the stator. I cleaned the carb out again but it didn't work either.



I just got a voltage reading at the handlebar switch connector as stated in the manual. It claims I should have a voltage of 13-16 volts at 5000 rpms. I am getting a reading of 6-8 volts at that rpm. This seems like a clear cut stator problem but let me know what you think.





Mailman

 

[T-Rex]

Sounds like you are on the right track, but to me if there is a stator problem you would have it throught the rpm range. JMO

Example: My Renegade ran fine no problems but if I let it sit over night it would kill the battery or even worse kill a cell in the battery. Two windings in the stator went bad and went strait to ground when the engine was not running. I know yours does not have a battery but it would effect your head lights a great deal. Some of the 04 YFZ's had issues with the stators and had to end up turning the lights on all the time so the bikes would run right. Have you got another CDI you could swap out real quick to see what that does.

 

[Mailman]

I already tried the CDI with another one. I even tried a 2nd aftermarket cdi. I also tried the coil, tested the kill switches, cleaned the carb twice, adjusted the valves, cleaned the filter, put in a new spark plug, cleaned the bike, sealed up the air filter boot, removed the spark arrestor screen, checked the fuel flow from the petcock, checked and cleaned the inlet filter to the carb, checked the tank venting, and even said a few prayers. Still no change.



That is why I am going to try the stator next. I found a used one and should have it by Friday. I will post the results.



I had a bad stator on a banshee that did the same thing; started, ran great until the upper rpms then crapped out. Hopefully this is the same thing.



Mailman

 

[T-Rex]

Sounds like that is it, let us know the out come. Yea your right on the banshee, had one do the same thing and it was a bad brand new Ricky Stator the second one.....lol

 

[Mailman]

I put in another stator and it DIDN'T fix the problem. I leaned the bike out from a 185 main to a 172 to try it and it DIDN'T change a thing.



Starts and idles great. Rev it up in nuetral and it starts to run rich, pop, miss in the higher rpms like it has an electrical short.



I have tried the black box (cdi) , stator, coil, spark plug, carb, air filter, tank vent, carb fuel strainer, valve adjustment, disconnected both kill switches, etc.



I don't even know what else to try besides the wiring harness.



Any ideas???



I was thinking about trying a completely different carb so I could rule out the carb.



Shoot me now!!!!!!!!1

 

[2slo4u]

i would try another carb. did you check for air leaks around the intake boot?

 

[Mailman]

I will try another carb on Monday.



Thanks,



Mailman

 

[T-Rex]

It my sound crazy but is your choke on?? Maybe loose??

 

[Mailman]

The choke is off. I have to use the choke to start the bike when it is cold. It revs the motors up like it should, then I turn the choke off and the idle comes back down.



It is rpm related.



What do you think about weak valve springs????



I am thinking about trying a different carb, new valve springs, and then a wiring harness.





Mailman

 

[T-Rex]

Well if the valve springs were week you have popping through the carb or exhaust. I can tell you this I spent 4 hours working on a Banshee the other day kinda did what your is doing and it was a loose wire crimp going to the coil on the positive side...

 

[Mailman]

It does pop. Are springs a possible cause of that?

 

[travis fulton]

It does pop. Are springs a possible cause of that?

what cam is in the motor? has it ever had a broken timing chain?

 

[Mailman]

It has a Hot Cams stage 2. The chain has never been broken.

Is it possible for the motor to shut down in a position where the cam is compressing the springs? The motor sat for 4 months or so. When we fired it up, it had this condition.



I have honestly tried everything but changing the carb out, putting in new valve springs, or changing out the wiring harness.



Mailman

 

[T-Rex]

It has a Hot Cams stage 2. The chain has never been broken.

Is it possible for the motor to shut down in a position where the cam is compressing the springs? The motor sat for 4 months or so. When we fired it up, it had this condition.



I have honestly tried everything but changing the carb out, putting in new valve springs, or changing out the wiring harness.



Mailman

Check the automatic decompression clearance.... Also check your timing, I have seen several cams turn a few degree's on the pressed hub where the cam sproket bolts up to.