[Stevers7012]

Hi my name is Steven I just bout an 89 Honda trx350d it runs ok needs carb cleaned drive somewhat. It clunks and rattles bad when in gear and in neutral. I’m pretty sure it’s not the motor but I’m the crank case. Can some one point me in the right direction on here. Haven’t had any luck finding anything. I currently have both covers pulled off and don’t want to pull apart any more if I don’t need to. Thanks for the help

 

[SlammedRanger]

Welcome to the forums! Someone will be along to help you soon i would think. I personally know nothing about utility quads. So i am of no help but a welcome wagon lol!

 

[Duck0fDeath]

I don't know a whole lot about the 350 motors yet but you might want to check your cam chain and the valve adjustment.

 

[retro]

^^^^ What he said ^^^^

Welcome to the forums!

 

[alloutdoors]

Welcome to the forum. One thing you may consider is firing up the quad and capture some video then posting it here so we have a better idea of the clunk you are describing as a problem...

 

[TBRider]

Welcome to the forums

 

[SamUK]

Welcome to the forum. One thing you may consider is firing up the quad and capture some video then posting it here so we have a better idea of the clunk you are describing as a problem...

^^ This ^^

A video will help pin point the issue, clinks knocks and rattles are difficult to diagnose without actually hearing them.
If you do a video, walk around the quad and engine so we can all get a good indication as to where the noise is coming from.

 

[_Wilson_]

Welcome to the forums!

 

[XplicitRacing6]

Welcome to the Forums!

 

[Stevers7012]

Ok I still haven’t put it back together yet to run it but I did find this today. Does anyone know what years will work on the 89 for a cylinder head and could this possibly make it clunk most of the time it runs but not clunk at some points. Has anyone else had this problem and I’m having a hard time finding parts

 

[Duck0fDeath]

When you hear the clunking noise it's probably your camshaft losing metal as it eats further into your cylinder head. It might not do it every rotation but you'll need to at least replace the cylinder head casing and the camshaft from what I can see in the pictures. Something must have come loose in there to start the carnage. You can pick up those parts used on eeebay. I have them too, mines an 87, and while the camshaft shows to be the same for the 87-89 models, my cylinder head assembly shows it's only for an 87. Not sure how accurate that is. Here's a great resource to help you find parts that are available, or at least get the exact part number for you to search for if it's unavailable.
https://www.partzilla.com/catalog/honda/atv/1989/trx350d-a

When you click on a part, it will list other models that part applies, if any.

 

[Stevers7012]

When you hear the clunking noise it's probably your camshaft losing metal as it eats further into your cylinder head. It might not do it every rotation but you'll need to at least replace the cylinder head casing and the camshaft from what I can see in the pictures. Something must have come loose in there to start the carnage. You can pick up those parts used on eeebay. I have them too, mines an 87, and while the camshaft shows to be the same for the 87-89 models, my cylinder head assembly shows it's only for an 87. Not sure how accurate that is. Here's a great resource to help you find parts that are available, or at least get the exact part number for you to search for if it's unavailable.
https://www.partzilla.com/catalog/honda/atv/1989/trx350d-a

When you click on a part, it will list other models that part applies, if any.

From what I found the camshaft for the 350 is the same from 87 to 89 and the head is the same from 86 to 89. I used partzilla already and everything is unavailable. I saw some heads on eBay but I can’t find a cam shaft ANYWHERE at all. I’ve copied part numbers and googled them and the noise is more of a chatter than a clunk if that makes any sense

 

[Duck0fDeath]

There doesn't appear to be any for sale at the moment, but if you do a search of completed listing, you'll see they do show up fairly often.

 

[Duck0fDeath]

If I was smart I'd get the spare I have on there quick while there are no others, lol. I had no idea they fetched so much $.

 

[retro]

The OEM cam is still available new as part #14101-HA5-000. All camshafts are interchangeable from 85-86 ATC350X and 86-89 TRX350/350D (86 thru 93 in Canada) models. You can search that part number on the fLeebay for an NOS priced less... or find it here at full price:

https://www.partzilla.com/product/honda/14101-HA5-000?

I expect the rocker arms will be junk too, so make sure you get a head with matching cover and good rocker arms... and no stripped holes or busted exhaust studs. The decompression shafts/levers all interchange (you can swap yours into any other cover) so any year TRX350 head and cover can be purchased.

You'll need a cam sprocket and a cam chain too, for sure. D.I.D is a good chain at a decent price savings over OEM, just don't fall for the cheap china knockoffs at about $35-$40, they are junk. For the sprocket you'll have to scrounge for a good looking used 14321-HA0-010 and hope...

Keep us posted if you can.

 

[Stevers7012]

I’ll keep you posted I’m trying to get the head off now but I’m having trouble getting the exhaust to cooperate. It’s loose and heat shield is loose

 

[Duck0fDeath]

Nice, Retro! That camshaft part number didn't appear in the parts diagram as an alternate option like they usually do.

You can remove the front middle engine mount bracket to easily get the header pipe out.

 

[Stevers7012]

Are you talking about this one. I’m assuming I will be able to rotate the whole engine and crankcase once it is removed

 

[Duck0fDeath]

That's the one. Two bolts on each end, plus the motor mount bolt in the center. With that removed you can remove the header pipe from the frame easily. No need to remove the heat shield off the header pipe even. I know what a pain those heat shield bolts are. The motor really wont rotate in the frame, even with all the mounting bolts removed. You have a copy of the service manual?

 

[Stevers7012]

I have one on my phone yes