1983 ATC185S fixer upper

[Footy]

So far I have: repaired the recoil, installed a new front tire, acquired a set of Ohtsu XO rear tires, installed new rear axle bearings, and ordered lots of parts.
If I do not have any major interruption's I should have it running in a few weeks.

[ATC King]

Are those NOS Ohtsu or new ones?

I looked online for the brand and didn't see any new ones labeled XO. I know some of the OEM tire patterns are being reproduced, but haven't seen any 22x11x8 or 25x12x9 versions.

[Footy]

Are those NOS Ohtsu or new ones?

I looked online for the brand and didn't see any new ones labeled XO. I know some of the OEM tire patterns are being reproduced, but haven't seen any 22x11x8 or 25x12x9 versions.

The tires I have are old and already on wheels. Ohtsu XA-801. They are at about 1/2 tread and amazingly do not have dry rot cracks. 22x11x8.

The 25inch was called Ohtsu XA-601 25x12x9. These tires are very hard to find.

[Footy]

I have run into an issue with the decompression lever.
I have been using this lever manually since the decomp cable is missing from this machine.
It has worked fine untill I adjusted the valves the weekend.
Now the lever moves but does not stay in the up position.
It seems like the "detent" that it normally functions with is no longer in place.
I do not know how a valve adjustment could cause this but it is connected in some way.

[ATC King]

The decompression mechanism doesn't have a detent, it's just an eccentric that pushes on the exhaust rocker tab to hold the valve open a little.

I suppose they can get a wear spot over time, a little bit of a flat area they may rest on. Maybe there's enough friction to normally hold them in place when engaged, that an if it's over-center. If the engine isn't at TDC, and is on the exhaust stroke, the decomp mech will not touch the rocker arm because the valve is depressed and it'll just spring back.

On the off chance the little pin area at the end of the mech broke off, you can remove the inspection cap and look inside to check that. If that dude broke off, it's floating around in the engine now, hopefully still up top somewhere.

Have you ever engaged it with the engine running?


Here's a picture of it, although some have a different lever, for a cable or by hand. The pin on the end is what I'm talking about.

[Footy]

I pulled the mechanism out. It looks like it should.
I hope that I got the valve adjustment wrong and that is why the decomp is not working.
My plan is to go back through the adjustment process and recheck everything.
Sometimes the "T" mark seems to lie a little on these flywheels.
I might pull the valve cover off so I can see the lobes and then do the valve adjustment.

[ATC King]

You can't adjust the valves with the cover off, the rockers are in the cover.

To make it easier to keep the crank where you want it, remove the spark plug. When you're fighting compression the piston doesn't want to stop or stay at TDC.

These are not high performance engines, there's a lot of wiggle room. As long as everything is close enough, you can adjust the valves.

That 'T' mark will line up on the exhaust stroke TDC too. Are you certain you adjusted the valves at TDC on compression? The crankshaft on a four stroke engine has to spin twice to complete the process, two strokes for each revolution.

[Footy]

You can't adjust the valves with the cover off, the rockers are in the cover.

To make it easier to keep the crank where you want it, remove the spark plug. When you're fighting compression the piston doesn't want to stop or stay at TDC.

These are not high performance engines, there's a lot of wiggle room. As long as everything is close enough, you can adjust the valves.

That 'T' mark will line up on the exhaust stroke TDC too. Are you certain you adjusted the valves at TDC on compression? The crankshaft on a four stroke engine has to spin twice to complete the process, two strokes for each revolution.

That is exactly why I plan to recheck. Typically I can feel a little bit of "play" in the rockers and know that I am on the compression stroke. These valves did not have play regardless of which stroke so I took a guess. I hope I guessed wrong.

[ATC King]

All you have to do to see it coming up on compression TDC is watch the intake valve open and close. Once it starts closing, look for the 'T' to come into view.

There's no need to stick anything in the spark plug hole, use a finger, or any of that.

[bigred22]

I own a '83 185s as well. Slowly I keep adding upgrades on better looking/working parts for it. I had it stored at a buddy's place for a few years. When I picked it up the front fender had a nice big crack in it that wasn't there before. I didn't get upset because he didn't charge me to store it at his place. I used a soldering gun to weld the crack until I came across a good fender. Today was that day, the seller had a few other nice parts and I grabbed those as well. So after the upcoming deep freeze we have coming, I'll get the parts swapped out. It isn't all that bad as it is now, but I still plan to keep adding nicer parts when found and the extra funds are there.....

[Footy]

That one looks nice.

I adjusted the valves again at proper TDC and all is well and the decomp lever is working again.
I was sick last week and must have had some brain fog along with it which led to the improper adjustment.
Also I basically have the rear end finished up: new rear brake shoes, replaced the chain and sprockets, etc.
Cleaning and rebuilding the carb is next.

[ATC King]

You figured out and nothing was borken. That's a success.


I can't say for certain, but I have a memory that someone had posted about a broken decomp, years ago. Maybe they were using it like a engine brake, although that's not exactly how valve actuated engine braking works. I've never seen one broken, but crazier things have happened.

[Footy]

I appreciate the input from the forum on my projects.
I should also update my 350X project thread.

[Footy]

Some progress has continued.
The sprocket cover and chain case are on as well as the shift lever.
The carb has been cleaned and rebuilt but not yet installed.
I am hoping to start it over the weekend to see if further tuning is required.
Will the 185 run good enough to tune without the air box?
I remember the ATC110 would not hardly run without the air box.

[Footy]

2 steps forward and 3 steps back.
I noticed when I would spin the rear axle some noise coming from inside of the chain case.
I rechecked the chain adjustment and it was good so I started looking closer at the chain case.
I found that the chain case was somewhat loose even with all of the bolts in place and tightened.
It turns out that the bolts that attach the chain case pass through rubber grommets on the inner half of the case and those grommets are rotten and destroyed which is why the case is not tight against the frame and rubbing on the chain and the small round plate near the rear sprocket and axle.
Surprisingly Honda still offers these grommets.
While installing a new front brake cable I also discovered that the steering stem bearings are shot.
More time and $$.