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Leftysdad

Mystery Sound 88 Fourtrax

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1988 honda fourtrax/foreman 350

Thought it was valves,  but had them adjusted....this sound is random...comes and goes....not constant,  but does it randomly....any clue? thanks in advance 

 

 

Edited by Leftysdad
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Most of the time those mystery topend ticking sounds that come and go are the auto decompression mechanism on the cam. I dont know anything about the utility quads and its possible this engine doesnt have one at all. But that has been my experiance with random noises that come and go.

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7 minutes ago, Leftysdad said:

It does have one.....you think it could be bad?  If that's even possible 

They arent usually bad. Just overtime get loose. They will make a real random ticking that is usually worse when cold. Gets better when its warmed up. But sometime at complete random will chatter and stop. If it has one mounted on the cam i would bet thats your problem.

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Replace the cam with one that has a new auto decomp mech on it. Or remove it. Is the quad pull start, electric start, or kick start? And no problem bud. Thats why we are all here. Always happy to help.

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That im not sure about. Like i said utility quads arent my thing. But on 400ex's we just remove them. They are electric start and its a carry over from when the same motor was in the xr400 dirtbike. Which was kickstart. And if it wasnt electric start i would never suggest removing it. Your kickstart backup will be alot harder to kick if its removed. On the 400ex you remove it from the cam. Press the sprocket hub off the cam and take it all off. You have to seal up the holes where it would get oiled. I always used jb weld and it worked just fine. Then you remove a little plunger and spring that went down into a hole in the cylinder head.

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1 minute ago, Leftysdad said:

20230924_154410.jpg

Oh yeah thats nothing like a 400ex. Ours are all internal. No lever on outside or anything.

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Its still could be. But your gunna want to wait for someone else to chime in. There are alot more utility quad guys on here. Someone should be along shortly. But your video and description sounds exactly like when a 400ex does it.

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Cam chain is stretched and needs replaced. You can use a small flat screw driver and play with the adjuster to confirm but that is what I hear.

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1 hour ago, Leftysdad said:

How is that done, I've never done it before,  thanks 

I think what Toodeep is referring to is  ,  on the end of the cam chain adjuster , there is a 8mm or sometimes a 10 mm hex screw , under that screw there is a hole , which a small thin flat screwdriver can be put into and turned to relieve the tension on the adjuster ---- I never knew that either , 

 

one way to check the adjuster is to remover it , the spring will relieve tension , then try to stick the adjuster back into the hole , you should not be able to make it go all the way back flush with the jug , there should be about a 3/8 gap , if not and it goes flush with the jug , then the chain is worn out , to reinstall that adjuster , you would need to screw that small flat head screw back with tension and hold it while sliding the adjuster back in ---- 

Do you have a manual ? 

 

The manuals are at the top banner , need a link for a manual ? 

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No , I don't have a manual, a link will be nice....which way do I turn the small screwdriver when I put in in the adjuster after removing the middle bolt 

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22 minutes ago, Leftysdad said:

No , I don't have a manual, a link will be nice....which way do I turn the small screwdriver when I put in in the adjuster after removing the middle bolt 

Here is a manual link --- you can only turn it one way , you will feel the very light  spring load 

 

https://drive.google.com/drive/folders/1hRCn9_Bcu8HgyrMDc3YcyX0EtzSgzE0b

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Insert the flat screwdriver into the end and turn the screw the tension will diminish , trick is now to hold onto to the adjuster and the screwdriver without letting it go and slide it nto the jug , hold it tight against the jug and put in screws --- how far in did the adjuster go ( how big a gap ) ?

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3/8ths or so....did not go flush.....it really seems to coming from the top end....when I put my hand against the head, I can feel it....when I put my hand on the bottom of engine, underneath,  I cant....but what I can't figure out Is, that it comes and go's 

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2 hours ago, Leftysdad said:

3/8ths or so....did not go flush.....it really seems to coming from the top end....when I put my hand against the head, I can feel it....when I put my hand on the bottom of engine, underneath,  I cant....but what I can't figure out Is, that it comes and go's 

 

 

Did you adjust the valves ? >>>  I do believe that 350 has 4 valves , double trouble --- Were you on the correct stroke when you adjusted them ? 

 

Did that manual down load for you ? 

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Yes, did that first 

Paid a shop here local.....they said if it was valves, it would be the noise all the time, it wouldn't be random 

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11 hours ago, Leftysdad said:

Yes, did that first 

Paid a shop here local.....they said if it was valves, it would be the noise all the time, it wouldn't be random 

So what did that local shop think the problem could be  

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Timing chain....but, when I removed the tensioner and checked it to see,  it didn't push in flush , it had the 3/8ths gap....which is supposed to mean the chain isn't stretched 

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