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kevin_c

trx350 mystery

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Found this section in the user manual (hiding in Ch. 20) thanks for pointing out the difference @Goober @shadetree. The replacement flywheel arrived today - complete with a one-way clutch and drive gear (seller claimed it was off an 86' TRX350). The original and replacement have slightly different numbers on the wheel:

 

original: 032000-4510 10EY ND JAPAN

replacement: 032000-4510 7EY ND JAPAN

 

Any thoughts on the EY part? 

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I would try it after comparing the teeth pattern, and timing mark and magnet? placement. You know everything else works. 

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I have found that part numbers are sometimes different on the same part , it could be from the part coming from a different vender , or is also used on a different model and they change the number for trace-ability ---- since I deal with a lot of used parts , I usually by the duck test , if it looks like a duck , smells like a duck , then it must be a duck 

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1 hour ago, Fishfiles said:

I have found that part numbers are sometimes different on the same part , it could be from the part coming from a different vender , or is also used on a different model and they change the number for trace-ability ---- since I deal with a lot of used parts , I usually by the duck test , if it looks like a duck , smells like a duck , then it must be a duck 

 

Everything checks out with the alignment of the timing marks, magnet placement etc. The replacement has 4 dimples where the original does not...

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1 minute ago, kevin_c said:

 

Everything checks out with the alignment of the timing marks, magnet placement etc. The replacement has 4 dimples where the original does not...

I would say them dimples were put there for balancing , and since you don't see any other differences , then the dimples could very well be the difference in the part number ---  maybe Honda realized they needed to be balanced and redone the original design -------  which ones is yours dimpled or not dimpled , I think I'd be wanting dimples 

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Well I found a matched flywheel and stator, new reduction gear, new starter, and finished the reassembly last night! I decided to start with the kickstarter and it fired right up as expected and no strange noises. Then I shut it off and hit the electric start - fired right back up! Looks like it is charging well 14.4 V when running. Hopefully that clears up all the left crankcase issues! I did notice that it was idleing fast after it warmed up - saw  a bunch of threads about this and going to try a few things. Really appreciate all the help from the dedicated enthusiasts here!

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Outstanding! glad to hear.

And bought all the correct parts the first time!

What next for this quad? Have you bled brakes yet?

for some reason brake fluid changes get put off way too long—it’s such an easy job

 

 

oh wait now you can check the cam chain tensioner 

Edited by Goober

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Hey @Goober

 

I've been going through the service manual looking at the maintenance schedule. I think brake fluid and diff oil are on the top of the list. 

 

At the moment I'm still stuck on the tapping sound coming from the engine. The cam chain tensioner looks good - shoots back out when I wind it up. I did a valve adjustment (and decompression cable free play) because the sound seems localized to the valve cover area (I bought an automotive stethoscope). It didn't seem to change so I adjusted them several times to see if I was just getting it wrong. Then I decided to change the valve adjustment screws - they came yesterday and I switched them out. The sound seems to be a bit louder. Its kind a higher pitched tapping, quite clear when the engine is revving down after I hit the throttle, and only noticeable after the engine warms up. The tippet screws I took out of the rockers have a clear X pattern on them. Any thoughts? I've read a bunch of threads on this but nothing seems to stick. Its really not an alarmingly loud sound, you have to pay careful attention to even notice it, but my paranoid brain picks it up and I want to take care now to prevent big problems later. 

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The other members will chime in, esp. if i have this wrong:

 

Take the adjuster out.

It will spring out to fully extended.

insert the extended tensioner.

the further you can insert, the more slack the chain will have.

should not be able to fully insert—should have a measurable gap.  I don’t remember how much gap.


to reinstall use a tiny screwdriver to lock the retracted adjuster in place then reinsert and bolt down before unlocking it

 

i had a picture but can’t find it

 

Edited by Goober
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Looks like about 1/4 in gap when the tensioner is fully extended and forced toward the cam chain. When its wound up it springs right back. I took a recording of the sound going to try to find a way to share it easily. Pretty distinct from the engine hum. 

171264981_241945144339522_5092612067957754478_n.jpg

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mine is pretty new and I can’t even get the base of the adjuster to the jug. I’m thinking you could use a new cam chain—in this blast from the past, this is discussed. @Shadetree advising another on cam chain. @Fishfiles and @jeepwm69 and others can also advise:

 

@shadetree to @JPelletier

“cam chain: pull the slack adjuster out of the cylinder, let it extend..which it will do, its auto. once you remove the slack adjuster out of the cylinder, try sticking it back in, like your gonna bolt it right back up, if your cam chain is stretched ?, ( which by looking at your timing marks ^^^..it is ! ), the bottom end of the adjuster will be very close to the cylinder. if your cam chain is say...new ?, then you would have about 1/2 inch ( give or take ) at the bottom before you reach the cylinder. loose rockers: you have to reach in, once the timing part is corrected !, grab the top of the valve, lift up, push down..feel any distance when you do this ? ( this is where my fingers tell me..lol ) use feeler gauges to set the clearance under the tappet to top of valve.”

Edited by Goober
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I think it is time to change the chain from that pic , look in the manual for the recommendation --- I can't remember the numbers off the top my CRS head , but know it is a lot more than that 

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3/8" & less it needs a new chain. It will run OK at 1/4" but the chain will slap the front chain guide and at 1/4" the chain may jump the upper sprocket at any moment. 1/4" is a time bomb....

 

D.I.D makes the best (OEM) chain for the TRX350s.

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On 4/9/2021 at 7:06 AM, retro said:

3/8" & less it needs a new chain. It will run OK at 1/4" but the chain will slap the front chain guide and at 1/4" the chain may jump the upper sprocket at any moment. 1/4" is a time bomb....

 

D.I.D makes the best (OEM) chain for the TRX350s.

 

I see. Mine measures out less than 3/8'' going to change it out. I'm hoping that will clear up the sound. Dennis Kirk has one - https://www.denniskirk.com/did/cam-chain.p119274102.prd/119274114.sku. Any tips for replacing it? I've done the right cover twice before and I think I've learned the important lessons the hard way. 

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This cam chain is 3/16” and done IMO.


I have 2 shop rigs that won’t run right; the tech never diagnosed this one as a bad cam chain. it only has 623 hours but they were hard.
 

But after the tech cleaned the tank and rebuilt the carb several years ago it sat unused because nobody would take it afield—couldn't keep it running. I rebuilt the carb and changed the manifold seal.

thought while i had the fuel pump off I’d check the cam chain—well now parking it til i get some money to fix it.

3693380B-C4BE-4B73-AF22-6D398EB212F5.jpeg

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Yup, it's done! You're fortunate that you were able to check the chain wear before it jumped time.

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Hi folks. I'd be happy to start a new thread for the benefit of others but I'll start here. Finally got a chance to replace the timing chain. The new one was noticeably longer than the one I took out and now the tensioner sticks out much farther when fully extended. Yay!

 

The trouble is a sound originating from the valve cover. The exhaust side is quiet but when I put my stethoscope probe on the intake side rocker arm bolt I can hear the exact sound (like a ticking or clicking) I hear just by listening to the engine. It gets louder when warmed up. I also see an uneven wear pattern on the tippets on the intake side. The exhaust tippets have a nice line but the intake pattern looks kinda smudged. This tells me that the rocker arm is moving horizontally for some reason - fairly certain that is the sound I'm hearing. I've read that some horizontal motion in the rocker arm is okay, so I'm assuming something about the valves, valve springs, or valve stems is off but there are no other symptoms. I've adjusted the valve clearance about 20 times with no change in the sound. The link is to a video of the engine running. Any advice is greatly appreciated this is hopefully the last thing to address before I can take this nice machine for a long overdue ride. 

 

 

 https://youtube.com/shorts/-NYo_i2Nc10?feature=share

exhaust.jpg

intake.jpg

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congrats @kevin_c i went to check out you video, i can't access maybe just on my end, just wanted you to know just in case it's not on my end. i sure would like to view and listen to that video.

 

i got the video to work. 

 

 

Edited by _Wilson_™
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@_Wilson_™Good job getting that video to work , I couldn't get it to work either -------  I don't really hear much >>>>>  too much rock music 

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thank you bro, but! i don't have any idea what i did to fix it.......LOL!  i just copied the link and pasted it in a search window hit return, next thing i know I'm watching and hearing his bike....... 

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That sounds way quieter than any other video I have heard of a motor running. The "Honda tick" isn't really that noticeable. Just going off of the video and what I can hear your chasing a ghost. Even a sewing machine makes noise when its parts are moving. Possibly it's different in person but most of the time videos really pick up on those little noises. 

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Thanks @toodeep. I'm pretty certain it originates from the intake side rocker moving horizontally as evidenced by the different wear pattern on the tippets. Does that concern you at all? I know my springs are nearing the service limit I'm wondering if replacing them would help.

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