1981 ACT200 Clicking

[NickN]

Hi guys,

saw thread below with very similar symptoms. I have just finished restoring my 1981 ATC200. When running, riding, etc. there is a loud clicking noise coming from the engine. I can't not determine if it's coming from the top end or bottom end. However, it sounds like it's coming from the piston. My valve lash is set at .005 on both. All bearings were replaced. Did replace piston and rings. Any advice on step by step troubleshooting ideas?

Thanks

[barnett468]

Hello


Did it tick before?

If not it is possibly cam chain adjustment. Check manual for instructions.

Is it a loud hard knock or a tick like a loose valve adjustment.

What piston type did you remove and install. There is occasionally a slight difference in size between piston mfg's. A smaller piston might tick.

[NickN]

Not sure what it sounded like before. It was barn parked for nearly 15 years.

I say I fooled around with the cam chain adjustment with no results. Checked the valve adjustments several times. Seems within spec.

I replaced the original piston with (New Standard Bore WSM piston kit for Honda ATC 200). No other reason than to replace. I did however take to a machine shop and let them hone the cylinder wall as well as level the jug to head connection. Even with new gaskets, the jug and head would not fit flush. Very little was needed though.

Would the knocking be visible on the piston? Before I remove the engine and disassemble for about the 6th time (lol), I want to be sure this could be my problem.

[barnett468]

Hello


The best thing is to male a video of the sound then put it on youtube.com and post the link here. Let idle for 15 seconds then rev it a couple times.

The fact that the bore is std suggests the bore has a potential for being worn to the point that it could tick.

If the shop actually removed material to true the cylinder you are virtually guaranteed to have more piston/cylinder clearance than spec calls for. This can cause a tick and possibly some oil burning IMO.

[NickN]

Would this be the cause of lots of carbon build up on the plug with on a few mins of run time? No smoking, however lots of carbon on plug.

[90guy]

I'm curious if you are hearing the famous 200 sewing machine sounding valves?

[kb0nly]

If your plug is black after a short run time then your running too rich. The noise could be many things but let me say this, all 200's have a tick... PERIOD.

I don't give a crap what anyone says, the 200's sound like a sewing machine clacking away no matter how much you put into them. It's just inherent to their design of the valvetrain. My 200ES has a fresh top end, new valves, new piston and rings, fresh bore and hone, new timing chain, etc etc... The top end is as new as your gonna get. It still has the same tick as it did before rebuilding it.

I had a 200 here that another guy was determined to get quiet, he bought a new cam, new rockers and rocker shaft, new timing chain and guide and tensioner, new piston and rings, and a new old stock cylinder that was stock bore. He spent a TON of money on the top end. Put it all on, did a very meticulous job of breaking in, etc. After about a month it started to tick in the top end, and its back to the same noise it made before. Now all those parts were replaced and new, so why would it tick nothing is wrong? Its just how the 200's sound in my opinion. Its been argued on here many times.

Now what i would do is get a mechanics stethoscope, they are not that expensive, $20-30 at the local auto parts stores around me and they come in handy. With that you can rest it against various parts of the motor, the rocker cover, the head, the side of the cylinder, etc. Pinpoint the noise by finding where its the loudest. A long screwdriver held to your ear works just as well, another old school tip for ya.. LOL

Also if the plug is black and its running rich you could be getting some fuel knock, aka detonation, etc... Before tearing the motor apart i would exhaust all options. Get the fuel mix right and pinpoint the source of the noise.

[NickN]

Great. I used my stethoscope but still couldn't pinpoint the noise. It almost seems to fade a littile anywhere I place the stethoscope. I found a YouTube video that pretty much sounds like my issue. Here's the link. I will however, record my engine tonight. The first time I heard the noise, I would have bet you it was an exhaust leak. That's what it sounds like, or the sound the clutch sounds if you were to tap it. Just a rapid clicking noise.

http://www.youtube.com/watch?v=_usPzIusAdY

I adjusted my cam chain both directions. Neither seem to make a difference. Of course, this doesn't mean I'm doing it correctly. I do however have all manuals and have followed everything to the T.

For 30 years old, it runs like new. Although at this point, it basically is.

[NickN]

Very well may be normal. Just want to verify that before I ruin all the time and love I've put into to this thing. I have it torn apart again, but when assembled, it looks like it just rolled out of the factory in 1981! Wow, is passion red hard to find!!

[barnett468]

Hello

Wow, is passion red hard to find!!

Not if ya know where to look, lol.

http://ww.colorrite.com/product/hond...n-red-1321.cfm

[NickN]

yep...that's where I purchased it.

[barnett468]

Hello

Hello, The best thing is to male a video of the sound then put it on youtube.com and post the link here. Let idle for 15 seconds then rev it a couple times.

Would this be the cause of lots of carbon build up on the plug with on a few mins of run time? No smoking, however lots of carbon on plug.

If the shop actually removed material to true the cylinder you are virtually guaranteed to have more piston/cylinder clearance than spec calls for. This can cause a tick and possibly some oil burning IMO.

Was it a new plug?

Did you change anything else during build ie carb, pipe, etc?

You are seriously rich. It should be same color as it was before rebuild, something is wrong.

Make sure choke is off!

[NickN]

Yes, I replaced the carb with one of those "top of the line" $40 China Models, I know, I know. Basically due to the amount build-up on the factory. I still have the factory and may re-install it. I just never have any luck with 4 stroke carbs once I start backing screws out. I simply bolted the carb on. No adjustments made.

I have noticed, even from cold start, I do not have to choke. Matter of fact, if I full choke, it will not start. As soon as I turn off choke, it fires usually on the first pull. Again, I may at the most have 15 mins of run time since I've rebuilt the engine.

Original tail pipe, but new valves, valve guides, piston, washers, seals, bearings. Also had the entire engine soda blasted and I powder coated everything except top-end. Engine runs strong. No smoking.

Another possibility, I recently purchased a new CDI witch I haven't installed yet. I believe my original CDI was giving a weak spark. It was borderline when tested with a meter.

Do you think the clicking sound could have anything to do with the clutch assembly?

[my1423]

Some noises are normal for these motors.

That is timing chain noise and it sounds bad.

Try this for adjustment.
http://www.youtube.com/watch?v=GpoHh9EMhaU

3 other things to check.
Pull the pulser and timing chain cover from the head.
Make sure the cam sprocket bolts are tight. These are notorious for backing out and making a heck of a racket.
If ran it will eventually break the cam, sprocket, chain, and maybe bent valves.
If the bolts are tight you can also see if there is slack in the chain.
Turn the crank back and forth and watch for play. Adjust tensioner and see.
You can also see if the chain is worn by wiggling the chain to see if it is loose at the top of the sprocket vs tight on sides.

Pretty much gona bet you need a new chain.
Its 20$. Can be changed in the bike but its a pain.
Pull the gear cover and pulser, cam, left case and flywheel.
then fish the old chain out and the new in.
Hard part is getting it over the crank end.

[barnett468]

Hello

Yes, I replaced the carb with one of those "top of the line" $40 China Models, I know, I know.

Must top of the line because they are $25.00 - $29.00 all day long. Is it gold plated, lol?

Basically due to the amount build-up on the factory. I still have the factory and may re-install it. I just never have any luck with 4 stroke carbs once I start backing screws out.

You will have to if you don’t want to jet new one.

I simply bolted the carb on. No adjustments made.I have noticed, even from cold start, I do not have to choke. Matter of fact, if I full choke, it will not start. As soon as I turn off choke, it fires usually on the first pull. Again, I may at the most have 15 mins of run time since I've rebuilt the engine.

Do the tests below first.

Put some gas in clear glass, if it is apple juice color or darker it is bad and will cause your plug to look like that.

GAS LEVEL TEST – If your gas level is low in the float bowl then your carb will be lean. Install clear plastic tube on bowl drain, hold open end of tube level with top of carb and open bowl drain valve. The gas will flow into the tube. It should be from level to 3/16" below the bottom of the carb body where it meets the bowl. If it is incorrect then adjust float accordingly.


PILOT JET - If gas level is good and it is like 75 degrees or above and starts with no choke drop pilot 3 sizes. If it is 75 or below drop 3 sizes.

MAIN JET – Drop 1 size, buy smaller spares for testing.

Engine runs strong.

Any flat spots, or burbles upon acceleration?

No smoking.

Should be some sort of black smoke according to plug description, oh well, lol.

Another possibility, I recently purchased a new CDI witch I haven't installed yet. I believe my original CDI was giving a weak spark. It was borderline when tested with a meter.

You can’t really test them even though the manual says you can, lol. How did you test it? As long as it runs good weak spark is ok. But by all means try that first.

Do you think the clicking sound could have anything to do with the clutch assembly?

Not if it’s in the top end.