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Discussion Starter #1
I have an '06 trx450r stock and it is hard starting once in a while. Most of the time it will start normal but once in a while it will ot start with out a pull start. I crank it over and the tone of the motor is different, just about like there is no compression. It will do it either warm or cold. I am sure it is the decompression vale doing it but what might cause it to stick open or is it something else? It has never acted up at home so I could find the problem. Spark is great, fuel is good, compression is perfect.
 

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how much time do you have on your motor since your last service?

you valve and decompression adjustment might be off. its a good time to check for clearance and adjust accordingly.
if you do that and still doesnt fix it at least you can rule that out.
 

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first off, are you sure your starter is not slipping and getting hot, or just worn out.

remember, dont hold the starter for over 5 seconds at a time. also dont give any gas while cranking the motor over.

ok now, like mentioned how many hours on the machine. or better yet how many tanks of gas in your mahcine. did you ever check your valves since you bought the mahcine? or the decomp?
 

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has it been a while since you adj the valves?

sounds like valves out of adjustment.....

if you don't keep the air filter clean and oiled.....(i clean mine every ride) it can pull fine dirt in causing the valve seats to start wearing.............. and that will make it not crank unless you pull start it.

if your decompression weight spring has broken, it can cause it not to start but it will not turn past the compression stroke.........the valves clearance will be .006" intake and .011" exaust and .021" decompression.

alot of people will tell you to set decompression with a compression gauge which is more percice but .021" works for me good.

imo ....it's valve adjustment. what you have 'm set at?......... bet you can't get a filler inner can ya!. bryan
 

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Discussion Starter #5
It is hard to guess how many hours but approx 12 thanks of fuel since I got it and who knows how many before me. I was thinking it had to be out of adjustment. I'll check it out but probably not touch it till my hrc kit comes in. I hope thats all it is. Th starter is not the issue it always canks the motor over even when you leave it in gear and bypass the clutch switch. Thanks for the help.
 

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It is hard to guess how many hours but approx 12 thanks of fuel since I got it and who knows how many before me. I was thinking it had to be out of adjustment. I'll check it out but probably not touch it till my hrc kit comes in. I hope thats all it is. Th starter is not the issue it always canks the motor over even when you leave it in gear and bypass the clutch switch. Thanks for the help.[/b]
check your valve clearance before you take the old cam out so you can figure what size shim to put back in, that is if it's out of adj. it may save you alittle time ..........not to have to take cam assy out twice.
 

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its a stock quad, most likely like mentioned its just valves. go ahead and check the clerances with a feeler gauge. takes about 10-15 min to check them. takes about 30 min to adjust them. then we can go from there. but i would def. fix it before you put the HRC kit on.
 

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I crank it over and the tone of the motor is different, just about like there is no compression.[/b]


my best guess.......



starter clutch........




just a thought.....
 

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I crank it over and the tone of the motor is different, just about like there is no compression.[/b]


my best guess.......



starter clutch........




just a thought.....
[/b]

since i dont have an ER......

Id imagine the starter clutch is inside the starter? or connected to the starter in the engine?

is that just a one piece part to fix?
[/b]
its a whole mess of a thing. the starter is behind the cylinder and through variance gears or reduction gears goes into the right side case where the main parts are, main reduction gear, starters clutch, clutch outer, starter gear, etc. the clutch is made up of many sprags which travel in one direction and are pretty weak. when the engine kicksback, these sprags on the clutch take a beating. they can wear off fast since they get pretty hot quick, that why honda trys to tell us to only use it 5 seconds at a time and never give throttle which can cause kickback.




arent many things that can go wrong with a stock 06 450er. starter can be one, esp if you havent had the recall done for one of the reduction gears. valve adjustment can be another.
 

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Discussion Starter #12
I am positive it aint the starter clutch. The quad will move the quad forward when starting it in gear with the clutch swtich bypassed. If the starter clutch was gone it would not move the quad while in gear. Plus I just put a new one in 7 tanks ago. I am checking the valve clearances this weekend, if I get the chance. I feel that is where the problem is. Thanks guys for all the imput. :thumbsup:
 

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QUOTE(TRX450_AB @ Jul 28 2008, 02:13 PM) index.php?act=findpost&pid=536512
<div class='quotemain'>I crank it over and the tone of the motor is different, just about like there is no compression.[/b]


my best guess.......



starter clutch........




just a thought.....
[/b]

since i dont have an ER......

Id imagine the starter clutch is inside the starter? or connected to the starter in the engine?

is that just a one piece part to fix?
[/b][/quote]

its a whole mess of a thing. the starter is behind the cylinder and through variance gears or reduction gears goes into the right side case where the main parts are, main reduction gear, starters clutch, clutch outer, starter gear, etc. the clutch is made up of many sprags which travel in one direction and are pretty weak. when the engine kicksback, these sprags on the clutch take a beating. they can wear off fast since they get pretty hot quick, that why honda trys to tell us to only use it 5 seconds at a time and never give throttle which can cause kickback.




arent many things that can go wrong with a stock 06 450er. starter can be one, esp if you havent had the recall done for one of the reduction gears. valve adjustment can be another.
[/b][/quote]


last time out one of our 07's had an issue. it would only start when the bike was cold. after riding and stopping my buddy would try to start it and it would just chug over a couple times.
 

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Sounds like the same issue i have on my bike...Starts on the very first kick when cold but after its hot almost impossible to crank..still havent figured it out yet...soon as i get a chance i will check compression PSI
 

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Sounds like the same issue i have on my bike...Starts on the very first kick when cold but after its hot almost impossible to crank..still havent figured it out yet...soon as i get a chance i will check compression PSI[/b]

you might have the decompression adjustment on the edge, to small a gap. metal expands when hot...........just a thought. :sorcerer:
 
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