[firefighter1731]

03 Foreman 450.New head,Bored with new piston and pin,New timing chain,New centrifugal weights .Oil pum was removed and checked according to Honda's manual .After reassembly I still have a noise and it sounds like it is in the top of the engine.It also sounds off pretty good at startup until I hit the trhottle and it calms down but never completely stops.While riding the noise is present and seems to somewhat increase and decrease depending on the load and if you coast or accelerate.I am up against a wall here and need some advice on what might be causing the noise.Any help would be appreciated.

 

[dirty4man]

are the valves set to spec?

 

[firefighter1731]

Yea they are right.I verified this yesterday and still have the tap at low idle speeds.

 

[firefighter1731]

Dirty I really think this noise is coming from the bottom somewhere.Like I said in the previous post it sounds like it's coming from the top.But in reality it may be coming from somewhere else.I believe the crank would show itself if that were a problem.What do you think???

 

[dirty4man]

if everything else looks ok, that only leaves the crank and the timming chain tensioner. both the crank and tensioner noise will travel through the engine making to hard to locate. I can't think of anything else in the bottom end that would cause a knock. The only way to know for sure is to tear it down.

 

[firefighter1731]

I checked the tensioner while I was replacing the chain and it was functional.I run it today and tried the old stethescope trick and it sounds like the noise is coming from the top and the side as well.I can hold the brake while in gear and give it the gas and perfect,no noise at all but slack up on it and there it is again.I will find it !!!!!!!! I'll keep ya updated...

 

[Mudd Dogg25]

same problem

I have the same symptoms, the engine ticks when I first start it up, and it will tick/rattle when i bump the throttle and it comes to idle. After it is warmed up, its ok. Has anyone found anything else??

 

[maa37maa]

i dunno i maybe wrong bout this but i tore my top end down and my valve guides had broke in half... may have been just a freak deal but just something else you can check...

 

[jrfonte1479]

my 500 has a knock kinda like that its always there cant figure out what it is though sounds like its right there in the top end. it started doing it when it had about 80 hrs on it and i tore it down couldnt figure out what it was everything checked out good with the crank and rod. while i was in there i put in a new web cam, big bore kit, and clutch kit, checked the specs on everything and it was all good. it almost sounds like one of the pushrods are slapping the side of there bore like its bent but there not.

but dont know what to tell you if you figure it out let us know what it was. i would like to know maybe the same thing wrong with mine.

 

[Minnesota Driver]

Mine has been noisy since new. Valves are to spec and still rattle. I can get it to quiet a little if I tighten them way up, but figured I better put 'em back to specs.

 

[theedz]

My 450 is the same way, and so is a buddies. We have tried everything to adjust it, and have tore it down. We just think that is how the 450's are.

 

[rasorbackq]

I just replace piston and rings ddid the whole thing and seemed to be a tapping in the top end. After I checked the valves they were not set up correctly . THERE ARE 2 TIMES FOR THE timing "T".
I had mine set in the wrong place . Rotate another 360 and adjust your valves there. Then move to the next "T" (same T) and check the valves again . They will be not adjusted correctly. Have to find the right "T"

Guess what I m saying is each "T" is not Top Dead Center TOD

 

[jrfonte1479]

shouldnt the t just be 180 deg from tdc on the compresion stroke to tdc on the exhaust stroke. you have to watch your valves and make sure to stop it tdc just after the intake closes when the t lines up in the crank hole.

but i know the valves are right on my 500 just makes noise. i thougth maybe i just never noticed it before but i cranked my 450 next to my 500 when it was running and you could hear the tapping of the 500 over the 450 running next to it but the 450 is quite no noise from the motor.

question for the op. did you check the side to side movement of the connecting rod on the crank when you tore it down? did the crank or connecting rod have any blue color to it?

i rebuilt a 450 for my buddy a while back after he drownded it out and the water and dirt scored the cylinder wall and the fire from the combustion chamber was leaking past the rings and over heated the crank and connecting rod turning them blueish color and making the bearings loose and it knocked when we changed the top end out( he was trying to get off cheap) and i had to go back into it and replace everything.

 

[Beccao1]

03 Foreman 450.New head,Bored with new piston and pin,New timing chain,New centrifugal weights .Oil pum was removed and checked according to Honda's manual .After reassembly I still have a noise and it sounds like it is in the top of the engine.It also sounds off pretty good at startup until I hit the trhottle and it calms down but never completely stops.While riding the noise is present and seems to somewhat increase and decrease depending on the load and if you coast or accelerate.I am up against a wall here and need some advice on what might be causing the noise.Any help would be appreciated.

Hi, have you checked to see if top end is getting oil? I have a rancher that ticks replaced All kinds of stuff but turns out oil is only going to top end at high idle.