[YellowRancher]

after my last post, I bit the bullet and went for an full rebuild motor rebuild. since I had an atv wreck back in early May, I was not able to do much with the Fourwheeler. After I took the motor to a local machine shop and got all the clearances and what not delt with. now that The Fourwheeler is put back together, I am having some problems with the carb not working correctly. when I start it. it runs wide open even with the idle screw as far down as it will go. Yes, I have cleaned the carb multiple times now. just today I took all the plastics off the sides and I took off the factory snorkel, alone with the air fiter off and It runs okay.
.
And also since I had rebuilt the atv, it doesn't sound like it use to before this top end and bottom end.it sounds like timing is off but I put a new chain and tentioner along with guides in it. Just thought if I could kill 2 birds with one stone. that it would be better then making 2 Threads about this.

 

[SamUK]

Sounds like your sucking air from somewhere. Check the rubber inlet boot (carb to motor) you can try whilst it's running by spraying starting fluid or petrol around the joints and boot.

Edit: Double check the timing. Is it timed to the correct mark at the crank?

 

[YellowRancher]

I will try what you are saying about the intake boot. The timing is spot on , I had used the manual as well as took it to a Honda shop just to make 100% sure that it is in spec. it starts everytime 0 problem it just sounds very weird to me \,not like it use to at all.

 

[j.dalton0309]

after my last post, I bit the bullet and went for an full rebuild motor rebuild. since I had an atv wreck back in early May, I was not able to do much with the Fourwheeler. After I took the motor to a local machine shop and got all the clearances and what not delt with. now that The Fourwheeler is put back together, I am having some problems with the carb not working correctly. when I start it. it runs wide open even with the idle screw as far down as it will go. Yes, I have cleaned the carb multiple times now. just today I took all the plastics off the sides and I took off the factory snorkel, alone with the air fiter off and It runs okay.
.
And also since I had rebuilt the atv, it doesn't sound like it use to before this top end and bottom end.it sounds like timing is off but I put a new chain and tentioner along with guides in it. Just thought if I could kill 2 birds with one stone. that it would be better then making 2 Threads about this.

On the right handle bar where the throttle cable goes into the throttle box there's a little bolt with the cable running through it and a rubber cover over that pull the cover back and adjust the bolt. That same thing happened to me after I rebuilt the engine, it happens when you screw the throttle cable into the carburetor and it gets twisted up, garenteed this will work, thanks

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[j.dalton0309]

I can't help you with the bottom end

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[YellowRancher]

I just took the carb off and put it back on. i figured out that i had been running my FourWheeler without a vent line connected through the carb. and the problem with the sound was fixed also when i did this. so runs fine, but im having trouble with some ticking in the top end. the valves are on .006 but i didnt adjust the valves on TDC, but im not 100% sure that you have to do that. also when my dad put the new piston in he chipped the side of the piton but i dont think that will effect anything, If it does i have the old pisyon that just needs rings if that could be the problem

 

[cmanningjr]

I just took the carb off and put it back on. i figured out that i had been running my FourWheeler without a vent line connected through the carb. and the problem with the sound was fixed also when i did this. so runs fine, but im having trouble with some ticking in the top end. the valves are on .006 but i didnt adjust the valves on TDC, but im not 100% sure that you have to do that. also when my dad put the new piston in he chipped the side of the piton but i dont think that will effect anything, If it does i have the old pisyon that just needs rings if that could be the problem

You needs to adjust your valves at TDC.. do you have a service manual??


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[SamUK]

The cam lobes face down when at TDC.. To confirm this you can take the plug out and put a drinks straw (or something none damaging) in the plug hole.

 

[YellowRancher]

okay. I did not know that you had to adjust the valves at TDC. everyone iv seen just adjusts them normaly. I hear just a slight knocking in my engine but the bottom end was replaced correctly, iv been told that the 350's have a slight knock kind of like a sewing machine.

And my 3rd thing is my clutch me and my dad have tried for 2 hours to get it to adjust right but when we start feeling pressure we loosen just a tad and it wont engage. sorry for so many question.

 

[SamUK]

http://www.hondaatvforums.net/forum...-how-adjust-your-clutch-manual-shift-atv.html

Try this link.

For most common issues you'll always find a 'sticky' on this forum, there are also many tutorials on YouTube for correcting Honda clutch adjustment.

Also, 99% of Honda ATV's do have a slight knocking/tapping sound whilst running, this is normal, but it is only a slight noise. If it doesn't sound right get it checked out as it could lead to something worse.

Hope this helps.

 

[SamUK]

okay. I did not know that you had to adjust the valves at TDC. everyone iv seen just adjusts them normaly. I hear just a slight knocking in my engine but the bottom end was replaced correctly, iv been told that the 350's have a slight knock kind of like a sewing machine.

And my 3rd thing is my clutch me and my dad have tried for 2 hours to get it to adjust right but when we start feeling pressure we loosen just a tad and it wont engage. sorry for so many question.

Just to correct those who've shown you how to adjust valves...

The 'normal' way IS to adjust valves at TDC, any other way IS incorrect. There adjusted at TDC as there is no load on them and you get the correct gap.

You may benefit from a FSM, you'll find one here under 'manual help' subsection of this forum.

 

[YellowRancher]

Okay Thanks, SamUK this fourwheeler has always had a knock even before my rebuild. I checked all the bearings they all looked fine, but i replaced them anyways. But i didnt replace the crank or connecting rod. But i checked for play in the connecting rod and its normal not extensive at all. But like i said. Iv been told ranchers are bad about knocks like this but i have never seen one knock like mine does.

 

[retro]

If it has a broken piston skirt it will knock constantly. Severely worn cam and rockers can make a terrible racket too.

 

[YellowRancher]

Piston skirt is fine considering it was a brand new top end that i put in. My dad did happen to chip the piston on the top but its not bad at all. The cam could be worn when i had the motor apart for my timing chain, it didnt look worn but i did not measure it either so it could be.

Here is the video of what I am talking about the knocking and ticking.

 

[retro]

You can identify a bad cam and rockers by just looking at the rockers... if a rocker is still smooth looking and still has a convex shape where it follows the cam lobe, it is probably fine.

If a rocker is worn looking and is developing a concave shape where it follows the cam, it is junk and will probably be noisy no matter what you do.

Severely worn rockers having a concave surface with obvious cam lobe wear can knock loudly and sound like a bad connecting rod.

I didn't listen to your video cause those are rarely helpful in determining motor knocks until the knocking is quite loud. So, just offering some basic info in hopes that you'll remember what those rockers looked like?

If you are unsure about the valve adjustment on your motor you can read the FSM and follow the procedure exactly as it says and get them readjusted perfectly. That means both cam lobes must be facing down on the compression stroke. If you try adjusting them any other way you'll always fail.

Hope this helps...

EDIT:
If you know for certain that the new piston that was installed is damaged, why don't you replace it with a new one? Not with a used one.... NEW! You've made another mistake... just fix things right and you'll have a lot fewer problems.

 

[YellowRancher]

SamUk, my dad built a couple motors over the years, and we looked at the cam and t didn't show much scaring, no deep valley. but I understand where you are coming from with the damaged piston. it has like a small chip on the right side of the piston, he size of maybe the end of a Pic. not bad I wouldn't think but I wanted to make sure if not im going to buy a new piston, proably a wiseco this time im tired of them amazon topend bullshit

 

[retro]

I recommend you stay away from Wiseco forgings unless you have a professional understanding of their bore requirements, clearances & operating characteristics. Stick with an OEM piston until you are skilled... they are much safer for you to own and operate right now. You been getting burned almost every time you work on your bike... hope you can get yourself turned around and be productive this next round.

 

[wheeler]

TOO me.. that sounds like your top end for sure! I'd have a serious look at your cam, rockers, & valve clearance!!!!!

 

[retro]

...... my dad built a couple motors over the years, and we looked at the cam and t didn't show much scaring, no deep valley.

If any of those rockers show any "valley" whatsoever, it is completely junk. They are either good or junk... that was the point I was trying to make above with the long explanation.

Since you claim they have "no deep valley", I'm sticking with my intuition... that they are junk along with the busted piston (and questionable bore and unverified connecting rod). Ask questions about this stuff... we all want to help you.