ATC 110 Valve Trouble

[MrGiggles]

I'm sure most of you have seen my previous thread about reviving my ATC 110. I've purchased a new carb and it seems to have a valve problem.

After I put the carb on I sprayed carburetor cleaner down it to see if it would run for a little bit. It sprays the mist right back out of the carb, although I did get it to fire a couple of times, blue smoke came out of the carb then. I think there is either crud holding the valve open, it is burnt, or bent. I guess the timing could be off also, but it looks ok. Any ideas on what it could be before I pull the head?

[85Tecate]

I'm sure most of you have seen my previous thread about reviving my ATC 110. I've purchased a new carb and it seems to have a valve problem.

After I put the carb on I sprayed carburetor cleaner down it to see if it would run for a little bit. It sprays the mist right back out of the carb, although I did get it to fire a couple of times, blue smoke came out of the carb then. I think there is either crud holding the valve open, it is burnt, or bent. I guess the timing could be off also, but it looks ok. Any ideas on what it could be before I pull the head?

Can be caused by alot of things. One common problem is improperly adjusted valves. Check clearances on the rockers before you do anything. An easy way to test the valve to see if tis leaking is pull the intake off and rotate the engine till the exhuast valve is open so you know the intake is supposed to be closed. Fill the intake valve full of fuel and see if it leaks down. You can do the same with the exhuast.

[MrGiggles]

Can be caused by alot of things. One common problem is improperly adjusted valves. Check clearances on the rockers before you do anything. An easy way to test the valve to see if tis leaking is pull the intake off and rotate the engine till the exhuast valve is open so you know the intake is supposed to be closed. Fill the intake valve full of fuel and see if it leaks down. You can do the same with the exhuast.

I forgot to say I already checked the valve lash, there is a tiny bit of space all the time except when the valve is opening.

[shortline10]

Sounds like the top end needs to come apart to investagate . If you could just get it to run for a few minuets it would probably get hot enough to seat and get the parts working correct again .

[MrGiggles]

Sounds like the top end needs to come apart to investagate . If you could just get it to run for a few minuets it would probably get hot enough to seat and get the parts working correct again .

I poured some gas down the intake, it did leak out but it probably took about 10-15 minutes. Today I'm going to remove the timing chain cover on the head and see if I can possibly check the timing.

Is the timing like my Bayou?

1. Set piston to TDC compression.
2. Rotate cam until dot on gear lines up with the bump on the head.
3. Install timing chain and tensioner.

[daniel_250r]

i think it sonds like you have the timing 180 off

[MrGiggles]

Yesterday I tried to take the top timing cover off the head and of course the Phillips head screws stripped out. I don't know why Honda would be stupid enough to assemble their cases with screws. It's going to have to wait now until I can get an extractor of some sort.

Thanks and happy Thanksgiving everybody.

[Gearheadtom]

An impact driver is your friend when working with screws like that.

[MrGiggles]

I did end up getting the screws out with a chisel and hammer. I also removed the spark advancer weights, but can't seem to get the plate off that they were mounted too. Is there a key or something holding it in? Should it just slide off after I remove the bolt.

[MrGiggles]

I'm going to go now and see if I can wiggle the plate off. I've been looking through the service manual and it looks like it should just slide off.

[MrGiggles]

I did end up getting it off by prying on it with a screwdriver and tapping on the cam bolt. Also got the cover off.

It is definitely off time, maybe not 180 but the T on the flywheel doesn't line up with the center of the cam bolts like the manual says it should. I do have a couple questions, what is the T on the flywheel supposed to line up with on the case to show TDC compression? And where is the "O" mark on the cam gear, and does it line up with the slit on the inside of the opening?

[MrGiggles]

I have a little update.

It's been so cold here lately that I haven't had the ambition to get up and get and work done on the 110. I determined the intake valve is leaking, and pulled the head off yesterday. Besides being really full of carbon, nothing is majorly wrong. I would like to get the valves out to re-seat and clean them though. What kind of valve spring compressor or tool do I need to get these out? I have a big one but it won't work on this little job. The shop manual doesn't go into detail about the head dis-assembly.

[Gearheadtom]

I've done it before on my 90 without a valve spring compressor, but I don't realy recomend the way I did it.
I can explain how I did it if you want.

[MrGiggles]

I've done it before on my 90 without a valve spring compressor, but I don't realy recomend the way I did it.
I can explain how I did it if you want.

Please do.

[MudBug]

http://www.youtube.com/watch?v=Ls7TCQ0U2Pg

Just use what this guy has. A c-clamp with a piece of copper pipe on the tightening side with a whole cut in it so you can get the kepers out. the video should explain everything. hope this helps, good luck ! :D

[MrGiggles]

That looks like a good idea and I will try it out tomorrow.

Thanks.

[Gearheadtom]

That looks like a better way, but here's how I did it:
I took the rocker arms out, then put the pins for them back in.
I then took a screwdriver and pried down on the valve spring using the rocker pin to pry against, then I removed the keepers.
Putting it back together is a little more tricky.
I'd pry down on the valve spring again, but when you do the valve spring goes crooked, so you can only put one keeper in.
slowly realease the spring until it catches on the one keeper.
Turn the spring 180 degrees carefully, pry down on it again and put in the last keeper.
Done

[Dirtcrasher]

I put a shop rag under the head, use a socket and smack the top washer of the valve, it lets the keepers fall out.

Then I use a long piece of tubing with holes slotted in the side and push down on it while using a magnet to get the keepers in.

Of course the right tool would be great, but I rarely do valve work and usually just for valve seal replacement :D

Creativity and persistence prevail, as long as no parts are compromised!!

[MrGiggles]

I got everything apart without any trouble. The valves seem ok and aren't bent but were very dirty and carboned up. I will clean them up and lap them.

I may have found a problem though. It looks like there's some surface rust on the top inch of the cylinder from sitting I suppose. Do you guys think it will affect anything?

[85Tecate]

I got everything apart without any trouble. The valves seem ok and aren't bent but were very dirty and carboned up. I will clean them up and lap them.

I may have found a problem though. It looks like there's some surface rust on the top inch of the cylinder from sitting I suppose. Do you guys think it will affect anything?

Get a bore reamer or have a shop ream the top of the bore to match the rest. This can cause wear on the piston/rings and even break rings if its bad enough. If its just surface rust though, and not stuck on flakey stuff you can just use a piece of emery clotch and smooth it down. Dont stay in one spot do long even strokes so you dont make it out of round.

[MrGiggles]

Get a bore reamer or have a shop ream the top of the bore to match the rest. This can cause wear on the piston/rings and even break rings if its bad enough. If its just surface rust though, and not stuck on flakey stuff you can just use a piece of emery clotch and smooth it down. Dont stay in one spot do long even strokes so you dont make it out of round.

I haven't done anything about it yet, it's not really rust, more of a discoloration. If it runs okay like this I was going to hone and put new rings in anyway.

Last night I got the whole engine put back together, but it only popped a couple times and plumed blue smoke out the carb like before. I think the timing is still off, either the timing chain or the ignition timing. I set the ignition timing to where the points start to open right when the F on the flywheel meets the mark on the coil. To set the timing chain I moved the T towards the head centerline, and matched the O on the cam gear to the notch in the head and installed the cam. I also lapped the valves down (Intake was pitted badly, exhaust was good) and they seem to be sealing good. The compression is much better, but probably won't be great until I get a gasket set.

[MrGiggles]

Nevermind

10 char

[MrGiggles]

Fiddled with it some more, still can't get it to run. Any tips for setting the ignition timing? I have verified that the cam timing is correct.