kevin_c

6 hours ago, _Wilson_™ said:

 

i can't hear much ether....lol! but, that engine doesn't sound bad at al, and @kevin_c the top end was refreshed recently ??

Yes sir. I replaced the valves, seals, piston rings, and gaskets. I didn't touch the rockers, valve stems, and the springs are original. The springs are close to the service limit. At the time I did the top end I couldn't find any. Since then I've acquired 4 new inners and 3 outers just in case. 

25 minutes ago, Goober said:

I don’t hear what you’re hearing kev. if you’re into the top end, you can look for parts but may take you awhile to collect them all together. 
theres a couple of orings in there, think they’re a little flat?

Thanks @Goober. Its probably clearer in person. Yes I was thinking about that also but the o-rings are on the bolt side of the shaft on the outside of the valve cover. I'm not sure to what extent they would help the rocker stay put. I remember when I worked on the cylinder head that one of the intake side valves had a slight wobble when I spun it. Decided to replace it and move on. Perhaps that valve stem is a little stretched and its causing the valve to tilt slightly pushing the rocker arm sideways. Hard to imagine since it runs so well, but this is my first rodeo.

7 hours ago, toodeep said:

From what I could hear in the video and going back and looking through the thread I personally would have no issues just running the machine as is. I see nothing that would cause any issues in the short and the long term riding of the machine.

Thanks for this very well could be a ghost

1 minute ago, Misterclean said:

It is a relatively light tapping sound. Probably the only proper repair is a new cam and rockers. It looks like it was run low on oil with uneven wear marks. Perhaps just run it until it gets bad? You could get the parts if available and just keep them for a future repair?

I'd agree with low oil causing uneven wear but the tippets are brand new. Cams and rockers seem hard to come by, but I'm going to take your advice and start looking 👍

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.

Thanks @_Wilson_™ for reposting the video in a better way. That ticking noise keeps me awake at night ☹️.

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

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. 

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. 

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. 

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!

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...

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? 

5 hours ago, shadetree said:

you are staring down a scary road here bro !. don't go buying and mixing stators, alt's , and all else unless you know for a fact you are buying parts for a 1986 trx350 fourtrax !!, REASON : this year MUST have a stator, flywheel, and matching gears to make it run. this model is a stand alone model for the electronics when it comes to firing the spark plug. why you ask ?..THIS IS A DC CURRENT MODEL !, all other models after are AC current models.

 Uh oh. Thanks @shadetree. I bought the used flywheel and stator based off part # 

stator: 31120HA7-671

flywheel: 31110-HA7-751

Not sure I understand what a DC current model means. AC is produced from the motion of the stator which gets rectified and regulated. Is that correct for the 86’ also? 

👍 to that

Thanks @Goober I'm keeping it original. I should have the holder and puller this evening and I'll take a closer look. The idler gears look great, along with the 18T side of the reduction gear and the 70T drive gear. Maybe someone was giving it lots of throttle while cranking the electric start? I'd hate to put all these good parts in and have it happen again. 

So my 86' has the cover in the upper picture (circled in yellow) without the bearing (#32). I'm curious if it would accept the setup from 87' with the bearing all the other parts look the same. Good suggestion @Goober

7 minutes ago, Fishfiles said:

Looks like 43/18 are the correct numbers for a 1986  and the other two gears are 25 and 21 ----  also I do believe the starter is different on the  1986 , what's different is the length of the shaft that sticks out of the starter , it  is longer on one (1986 )  or all the others ( 87-up ) , I am not sure which one is longer , my main stay on 350s is taking the rear ends out of them and selling what ever is left 

I see. I will need a new starter also the teeth on that are damaged. The 43/18 reduction gear is still available, and I found a junker for the flywheel and stator. Still not sure why all this happened, or why the one-way clutch seems intact. Maybe I'll know more when I pull the flywheel. 

19 hours ago, Fishfiles said:

I did talk to the 350 Guru and he said a 86 is a stand alone year for the stater gears , I asked him to stop by when he gets freed up ----   What I am saying is what you need is very rare 

 

I just thought of something else I forgot to ask him about , the stator -------   I know my 300 had two options for the stator , they were interchangeable as long as you changed it as a set , flywheel matching the stator ------    I just looked at the 350 stator and they do show two different ones by years  , but  what might be happening with the 350 is , it is not a different amperage stator like the 300 , but the 86 350A was a/c  , then the next gen 350 D was  d/c ---- so don't jump into ordering parts to quick as you might get the wrong stuff , e-bay and other sellers will either lie or don't know and will tell you stuff fits and it don't ----- 

Thank you. I was reluctant to hop right into buying parts for the reasons you mentioned. It looks like my first reduction gear is 43 / 18. Funny enough, only the out 43 side is damaged. The inner 18 look fine, along with the other gears on the spindle all the way down to the main drive gear. 

14 hours ago, toodeep said:

If your on FB in the group Honda Hoarders there was a guy that just posted some 350 parts for sale, yesterday I think. He had 2 motors that looked to be complete and was either 86 or 87, I didn't look close enough but they had the lower left crankcase breather and tank. He might part them out or if by chance your close enough it would be a bunch of parts.

On it  - thank you!

57 minutes ago, Fishfiles said:

What a mess , I seem to remember reading about different year  350s having different starter gears --------    did the electric start ever work for you since you got it , did you ever swop out  any of the starter gears ????  

 

So now that you got the tooth out the flywheel and the start gears freed up , does it turn over now ? 

Indeed a mess. I didn't try the electric start but I did verify that the starter worked when it was pulled off. I didn't touch any gears. The previous owner said the e-start stopped working a long time ago and he just used the kickstarter. I assumed it was a bad starter or a wire or something - poor assumption on my part. 

It turns over fine with the stator out, both by rotating the flywheel bolt and with the kickstarter. 

Hey Folks. Its been a fun yet perilous journey. Using advice from other threads and here I ended up doing a top end overhaul - valves, rings, seals, cylinder care, etc. Once back together it fired right up using the kickstarter! No smoke and it sounded great. I made the decision to address the electric start issue later (mainly because I wanted to use the bike in a dog trial this past weekend). When I got it to our club grounds, it ran great for about 5 minutes and seized up again. I heard a grinding sound as the engine quit sounded like it was coming from the left side of the crank case. Well I pulled the left cover off and discovered a chewed up starter reduction gear...and worse. One of the teeth ended up in the stator which chewed up the flywheel - horrible. So, I'm beginning to think that the "seizing up" I reported in the beginning had nothing to do with the top end and all to do with the starter reduction gear. 

I haven't pulled the flywheel yet (waiting for the puller) but the one-way bearing seems to be okay (when I turn the main drive gear it doesn't have any play and catches immediately if turned in the opposite direction.)

At the minimum I need a new flywheel, stator, and starter reduction gear :(. 

IF the one-way clutch is in good shape, any ideas why the reduction gear would get all chewed up? 

Side notes and sad stories from the top end rebuild:

1. I stripped out one of the 7x145 mm flange bolts that bolts on the valve cover. Had to call 13 places to find it off a junker (now I've got 2 extra if anyone else needs one 90052-HA5-67). 

2. My brother was clearing the crank case side cylinder gasket with a razor and he dropped it into the right cover side hole. He then took a magnet on a piece of fishing string and ended up dropping that in there as well. We took off the right cover, found the razor and magnet. During reassembly we didn't notice that the reverse stopper level spring pin had popped out before we torqued the cover down. Ended up with a 1.5 mm diameter hole in the seam between the cover and crank case - horrible. Used a product called alum bond to repair, seems to hold oil well. I learned to hold the reverse stopper lever spindle in with a screwdriver while I put the cover on. Hard lesson. 

2 minutes ago, retro said:

 

Not reliably no... you can look at the teeth on the cam sprocket to see if there is a lot of wear on the tips of the teeth, but you'd be making a judgement call about the condition of the chain without proof. The only way to be sure is reinstall it and check the extension of the chain tensioner. Since you have the motor apart it might be a good idea to replace that chain anyway right now to insure that ya don't have to go back inside later on to replace it.

 

The best manufacturer for new TRX350 cam chains is D.I.D. You can find DID chains for sale on eBay and elsewhere on the 'net. You'll need a new right side cover gasket if you decide to swap in a new chain. Let us know if you decide to swap the chain, we can give ya a couple pointers on R&R-ing that side cover that might save ya some time.

  To my untrained eyes the cam sprocket looks good. I was hoping to avoid taking the covers off but since I don't have a good understanding of what went wrong it is probably a good idea. 

1 hour ago, shadetree said:

if a valve is bent as you say ?, chances are..it smacked the top of the piston !. when this happens?, most times its because the cam chain is stretched , and allowed the valve to jump time, and hit piston. you can check the cam chain without tearing the motor apart.

Thanks shadetree good point. I've read in other parts of the forum how to check for stretch in the chain while the top end is still on the motor. Is there also a way to check when the top end is disassembled? Right now my chain is just hanging there above the crank case while I work on the top end.