Ok, so I adjusted the valves a couple weeks ago, piston was TDC (i think) and the valves were loose to the touch, I used a .006 feeler gauge and tightened as supposed to. Eng ran much quieter, but I noticed the exhaust not "hitting" like it used to...you should be able to feel the exhaust "pulse" from several feet back...thinking the valves are too tight, I re opened everything, but now w/ the timing mark "tdc" the valves are tight, not adjustable.
HELP!!

 

Forgot to tell you what it is...TRX300FW

 

12guns you have to be on the compression stroke to adjust the valve's , when you're on the compression stroke both intake and exhaust valve's will be closed ; one sure way to tell when you are on the compression stroke is to remove the spark plug ! After you remove the spark plug put your finger in the spark plug hole , then turn flywheel untill you feel pressure pushing again't your finger ; then line up the timing mark's then you use your filler gauge to set the correct clearane gap between the rocker arm and the valve stem ! Like i said i don't have a manual for the TRX 300FM , but on the TRX 350 FM the valve spec.'s are :Intake valve's are .003 inch and the exhaust :.004 inch ; and on the TRX 250 it's : .003 inch on both intake and exhaust valve's ! The wear limit is : .006 inch on both the TRX 350 and the TRX 250 ; i hope this help's you out ! ..................

 

Thanks for the reply. That does help. I lined up the timing mark by pulling the plug and slowly bumping the kick start. It lined up w/ piston "top dead center" but may have been on the up stroke. I don't know enough about how the valves work to understand all this, but i know they are closed now, and the piston is a high in the jug as I could get it...when do the valves open? On the down stroke after combustion? Last time I adjusted them, the timing mark was aligned and I didn't have to do anything, the valves were loose and able to be ajusted. Now they are closed, what else can I check to ensure all timing is ok and get the vavles to open?

 

I turned the eng while checking the valves, when they have play, they are opened. Question is, what's the significance of top dead center? If they are opened, they are opened right?? I'm working on the adjustment now, how will I know if they are too tight? won't close all the way??

 

12guns iwas trying to reply to your post just a few minute's ago when all of a sudden the power went out , it just now came back on and i had to restart the pc ; but this is how you adjust the valve's ! But first off let me explain how the 4 stroke engine work's , the first stroke of the engine is the intake stroke , then you have the compression stroke , then the power stroke and last is the exhaust stroke ! The engine has to be on the compression stroke to aline the timing mark's , when you are on the compression stroke you will feel pressure pushing again't your finger if you put it in the spark plug hole ; when you start to feel the pressure start pushing again't your finger Stop turning the crank shaft ! Get a peice of tree branch and cut it to size where you can stick it in the spark plug hole , then slowly turn the crank shaft using the kick starter untill the piston is at the top of the cylinder and the timing mark's should be alined at this point ; then you can safely adjust the valve's ! But you must do the adjustment when the engine is cold , when you find top dead center on the compression stroke the timing mark's should be lined up and your valve's should be closed ; and if you can't wiggle the rocker arm's then the valve's are to tight and will need to reset the gap between the rocker arm's and the valve stem's ! If you go past TDC on the compression stroke you will have to find it again using your finger in the plug hole , it has to be at the very top of the stroke to get the valve's adjusted right ! Let me know how it goes , and i will be glad to help you all i can ; to help you get them set right ! ..........

 

By the way 12guns what year model is your TRX 300 FM , and are you sure the valve's gap is .006 , where did you get those spec's my old 1986 Honda TRX 350 Foreman 4x4 had the valve's spec's At .003" inch for the intake valve's and the exhaust valve spec's were .004 " inch since i don't have a shop manual for a Honda TRX 300 FM model and don't know what year your quad is i can't be sure if the 300 spec's are the same as the TRX 350 Foreman of mine ! However i do have a manual that cover these model's , from a INTERTEC Maintenance Manual 2nd Edition ; it cover's these Honda model's : TRX 250 : 0.003 inch . Honda TRX 250X : Intake and Exhaust : 0.004 inch . You should call around to a few honda dealer's and ask them what the valve clearance's are , that's what i do ; most honest dealer's will give you this info at no charge if you buy a spark plug or oil filter from them ! And good dealer will give it to you at no cost over the phone weather you bought anything from them ! If i knew the year model you have and you can't get the info from a dealer near you i could call my AC dealer ! She can tell me what any year Brand make and model because she has worked on them all , she's an ex Moto Cross National Champion at 8 yrs. old and even went on to Bush Series Stock Car Racing before her main sponser Maiden Form fell on hard time's and had to file chapter 7 Bankrupt protection ! And right before i bought A new 2006 Arctic Cat 400 FIS Auto with the Suzuki 376cc Engine and Suzuki Duramatic Belt Driven Clutch Tranny , that's one thing i thought i would never own was a Belt drive atv ; but i knew and trusted Tammy Kirk ! And she gave me her word that not one belt drive 400 AC had been brought in with belt drive clutch issues since 2001 when she opened her Arctic Cat Dealership ! And she went as far as her Garrantee she would replace the belt and clutch system if it ever goes out before i get it payed off , and won't have it payed off untill Feb. 2010 ; that's one year after my Cat Care Warrantee run's out ! She also got me the best financing of all the other Brand's would give with my Credit History , she didn't do the Financing with AC Credit they were higher than the bank she set me up with ; she got me financed for a fixed rate of 5.9 Percent ! I tried Honda , Suzuki, Yamaha and Kawasaki they all wanted to set me up with their variable promotional rate , whitch after figured out that it would've taken me over 10 yrs. to pay off with their payment plan ; with the no money down zero finance for 12 months and a low $69.00 per month payment ! I can't believe how many people they sucker in every year with these end of the year sales promotions , but there's one born everyday ; and they love it when they find them ! OK let me know how your TRX 300 FM Turn's out and the model year will help ! ......

 

Ok here goes...93' trx fw
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I aligned the timing mark and the valves were closed, no play to adjust w/. w/ the piston on the up stroke but not all the way up, they are opened and able to be adjusted. How do I reset the gap from scratch as you suggested? I have a manual and am confident of the .006 gap.
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second question the rpms have to get up before power really kicks in...it still has power enough so most people wouldn't notice, but I can tell. It also doesn't "pulse" like it used to out of the exhaust. Should the correct valve adjustment cure some of this problem? Maybe clutch is going bad?

 

any takers?

 

please??