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Was wondering if anyone had done a manual cam chain tensioner on the forums and had detailed instructions on how to do so? I've seen the instruction packet that comes with the tensioner Im lookin to buy but its pretty vague... Thanks for any help
 

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I have done it for others and I always wonder WHY?

There is no performance advantage, it complicates maintenance and adjusted incorrectly will shorten cam chain life or at worst, damage the cam chain tensioner and cause engine damage.

I think some folks think that a manual tensioner is "simpler" than the automatic and less prone to failure. I have built and raced many different brands of motors. In my early days, I drag raced Kawasaki 900/1000's. Those bikes had manual tensioners, but they were spring loaded and adjustment was routine. When the automatic tensioner appeared, there were some cases of the tensioner "sticking", the cam chain got loose and started making noise. The tensioner then needed to be removed and serviced. Under severe conditions of high load caused by highly modified engines, there were reports of automatic tensioners backing off during deceleration leading to engine failure. Apparently none of my engines were that highly modified because I never experienced that phenomenon.

I have raced Honda engines with automatic tensioners since 1997 and haven't had a failure yet. My current race engine is a 2004 and while I have replaced the piston and valves multiple times, I have not needed to replace the cam chain yet.

Installation of the manual tensioner is simple: put the engine on TDC of the compression stroke. Remove the automatic tensioner. The tensioner gasket is metal and should not be reused. If the engine has been worked on and the tensioner gasket is of the cheaper paper variety, make sure all of the old gasket material is removed. Use care not to gouge the gasket surface when removing the old gasket or you will create an oil leak. Install the manual tensioner. Turn the tensioner adjusting bolt in by hand until resistance is felt. Start the engine. Back off the tensioner bolt until you start to hear cam chain noise, then turn the bolt in until the noise disappears. )It only takes about about 4 lbs of pressure against the tensioner blase to keep the chain from making noise. More than 8 lps of pressure will prematurely wear out the tensioner blade and the cam chain.) Hold the bolt in position with a wrench while tightening the lock nut with another wrench. Don't over tighten the lock nut. 8 to 10 foot pounds of torque is sufficient. Now ride, whenever you hear cam chain noise, readjust the tensioner.

The only advantage I can see for a manual tensioner is cost. About 1/2 of what an OEM automatic tensioner costs. Thanks, but I'll stick with my auto-tensioner.
 

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I just bought a 2013 trx400 , was curious if it has a auto tensioner how do you know if the tensioner is bad or its the actual chain needing replaced? ive also read people using a manual tensioner but after reading this not sur ei would go that route & people using a 450 cam chain as a upgrade so less stretch??
 

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Does you tensioner look like #6 HERE? If it does then it is automatic.

You find out if the tensioner is bad by removing it and inspecting it. I have an 04 CRF250X and an 05 TRX400EX and have not had a problem with the tensioner and the CRF gets torn down twice a year for maintenance - the TRX has never been apart. I have not experienced or seen a failed auto-tensioner. I work in a shop and have seen hundreds.

What makes you think you might have a failed tensioner or defective cam chain? My 04 CRF has not had a cam chain replaced, although I plan to replace it at the next routine tear down as a matter of preventative maintenance.

You check the cam chain one of two ways - 1) remove the tensioner without locking the mechanism (be sure to break the screw loose that seals the reset mechanism inside the tensioner body) - if it has the OEM metal gasket, it will push away from the engine as it is loosened (if it has been worked on and has a cheap paper gasket, you may have to break the adhesion of the paper to the parts before it will move - even if it has the OEM metal gasket, it may need a tap with a plastic hammer or screwdriver handle to break it loose) - if it moves more than 6mm (1/4 inch), then the chain is not worn sufficiently to require replacement - also, if the tensioner pushes away from the engine it is an indication the tensioner is working as designed.

As to the 450 cam chain - don't do it! The CRF450 is designed for racing and the chain is cheap (replacing the chain regularly is considered a cost of racing). The CRF chain is lighter, wider, it does not fit the sprockets correctly, is too wide for the tensioner slider and wears out faster due to the lighter materials used. It will wear the polymer side rails off the chain slider, the polymer will migrate through the engine and once the rails are gone the chain will contact the sides of the cam chain well which will shave aluminum from the well and the metal particles will migrate through the engine also. I have seen that and repaired the damage. If you are racing the TRX400 and need an extra 100th of a horsepower at 9000 rpm, then put it in and GO FOR IT! Repair the damage the next time the engine is torn down for maintenance. It becomes a cost of racing.

As to the manual tensioner, it's your call. I have installed them for the die hard idiots who insist that the auto-tensioner is not foolproof. These are the same ilk of people that didn't trust oil injection pumps on the two strokes. I never saw a failed oil pump on a two stroke that had oil in it. The only failed oil pumps ran dry until it locked up. I have seen failed oil pump drive gears, but the pump itself did not fail. Then after the manual tensioner has been adjusted by the owner and worn out the cam chain and slider, I install a new chain and slider (about $500) and give it back to them so they can do it again. If you install a manual tensioner and pay attention to the mechanic as to how to properly adjust it, it is fine - you just need to check the adjustment routinely as it will need to be adjusted manually regularly.
 

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I just bought my trx and was asking about a tick figuring its just valve adjustment but someone said it could be timing chain. I was just gathering all the information i could in case. In my experience usually if its timing chain the tick doesnt go away when she is warmed up, my tick is only when she is cold, as soon as it warms up its gone. and advise would be greatly appreciated as ive been off dirt over 25yrs just been riding street.
 

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Just a tick when cold? Completely normal. It's an air cooled engine - there is no water jacket to insulate and keep noise inside - also, the cooling fins amplify the noise making it seem louder than it is. You ought to hear my 05 - it has cam chain noise (normal) piston slap (normal for it's age) clutch rattle (normal and reduces when the clutch is disengaged) - an over head cam engine does not have valve tick (unless the valves are extremely loose and they tighten up with run time - valve adjustment is required to maintain adequate clearance).

Street bike engines are quiet compared to off road engines. Off road engine are put together 'looser' to perform better and resits the heat generated bu high rpm and hard running conditions. Any noise - as long as it doesn't get progressively louder - is somewhat normal. If the noise is loud, gets louder with higher RPM or appears suddenly and is accompanied with a hiccup in operation, then it need to be looked into immediately.
 

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Yeah, the auto decompressor can make noise and the 300 does not have one - the decompressor can be removed from the 400 cam and it functions just fine - Hot Cams do not have a decompressor and requires removing the actuator spring and plunger from the head and the engines start fine without it. You might consider having the decompressor mechanism removed from your engine.
 

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After researching it more and checking out Parts diagrams. It appears the 2013 does not have the decompression spring, mechanism. 🙂 I guess that's good news. . I sent you a p.m. As well.
 

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I just checked - Honda did away with the auto decompression in 2008 - 2007 was the last year that had the decompressor mechanism.
 
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