110 Valve Help

[Micahdogg]

I got a 1979 ATC110 earlier this year that ran decent, but was a bugger to get started. One day it wouldnt' start and when I pulled the plug I noticed a small bashed area by the end of the threads. Turns out the spark plug was too long and hit something.

I pulled the jug last night and it looks like the intake valve might have been clipping the end of the plug. The pistion has several marred spots on the top, but it doesn't look like it was contacting the plug...looks more like a piece of plug got hammered around (or a piece of valve, or just prior damage).

Either way, the bore looks decent, rings looked good and it ran pretty decent beforehand so I'm thinking of scuffing the cylinder up, getting new rings and addressing the valves. I don't think the Autozone valve spring tool will fit in the 110 head though - so how do you guys pull the valves? Also, how do you fix the seat if it's all boogered up? I'm hoping to avoid machine shop costs.

[El Camexican]

I'm hoping to avoid machine shop costs.

Hope all you want, it ain't gonna happen. You'll spend more money on tools than the shop will charge to to tear it down and I suspect you aren't qualified to make a repair of this nature. Take it to a small engine shop and get it done right, you will be glad you did.

[Micahdogg]

Where is your sense of adventure?

I might have a 84/85 head with decent valves - haven't looked at it closely. Do you know if that head is a plug and play on a '79?

[El Camexican]

LOL! I've had and paid for enough adventure to know when to take something to a pro. No clue on the plug and play question, but someone here should. Looking forward to outcome of this.:beer

[Micahdogg]

Well, I made a tool to remove the valve springs. I found out what happened. The spark plug was too long and the intake valve was opening into the plug. It was slowly mchammering away at the last few threads on the plug - which is probably why it got worse after a friend of mine revved it out real good. The edge of the valve slowly rolled over into the seat. It doesn't look like the seat took much damage at all, but the valve just kept rolling more and more until compression got so low that it wouldn't fire. I ordered two new valves and a vesrah top end kit. With as little seat pressure as this has, I'll lap the valves in place, assemble, fill the chamber with liquid and see if it bleeds through as bad as it did tonight. If it passes that test - I'll just assemble it as is.

The sucky part is that I want to throw some new rings in, but can't find any rings for a 79 110. And I'm not interested in upgrading the piston. It ran ok before so if I have to, I'll just keep the loosey-goosey cylinder.

[yaegerb]

here you go:

http://www.ebay.com/itm/HONDA-ATC110-ATC-110-PISTON-RING-SET-1-00-O-S-/250917382523?pt=Motorcycles_Parts_Accessories&hash=item3a6bd7697b&vxp=mtr

[Micahdogg]

I think I'm on a standard bore (51.9?mm). Aren't those for an overbore?

[yaegerb]

yes, those are overbore.

[Micahdogg]

So can I just trim/file them down do you think?

[yaegerb]

Ok...
here you go: More expensive because it comes with the piston, but you can get the rings in standard bore if you don't want to increase the bore of your cylinder.
http://www.dratv.com/at1ovpikit.html

[oscarmayer]

hey, I have standard bore rings! the chinese use a honda "clone" engine and their 110cc uses a 52mm piston, they would work perfect for you. I have i think 1-2 sets of those rings and head gasket to match. i'll double check this weekend and if I I do your welcome to them for shipping costs + $5 for a burger and fries. ;)

why do I have those parts lying around? My son races custom prototype chinese ATVs for MX and the factory sponsored us for a while so we have tons of stuff for them. i have like 7-8 gasket sets as we were always goign through motors. We went through 4 montors the first season. and halg way through the 2nd season we were at 2 motors already when we had to quit doe to something happenning in our famiyl lives. anyway, the new engiens I run that I got before we ended sponsorship run 54mm bores now not 52mm so i really do not need the 52mm stuff. I'll keep a few things on hand jsut in case but that's it.

[El Camexican]

So can I just trim/file them down do you think? NO! The ring would be oval.

[Micahdogg]

This looks promising! Do you know if they are the right rings for the 79-80 ATC110's? They are either thinner or thicker than the 52mm 81+ piston rings. I still haven't figured out what the difference is, but it seems like no one is supporting the 79-80 pistons any longer.

[yaegerb]

This looks promising! Do you know if they are the right rings for the 79-80 ATC110's? They are either thinner or thicker than the 52mm 81+ piston rings. I still haven't figured out what the difference is, but it seems like no one is supporting the 79-80 pistons any longer.

yes, they are...

Look above at the link I sent you yesterday

[Micahdogg]

You sent me a link for overbore 79-80 rings. I don't want that.
You sent me a link for a new piston with the rings. I don't want that.

Now if Oscarmayer has rings from a chinese motor that are the right size thickness for a 79-80 standard 110 honda piston - that is what I want. If his standard 110 piston rings fit a 81-85 - that is not what I want. I thought I was pretty clear in what I was looking for.

[yaegerb]

You sent me a link for overbore 79-80 rings. I don't want that.
You sent me a link for a new piston with the rings. I don't want that.

Now if Oscarmayer has rings from a chinese motor that are the right size thickness for a 79-80 standard 110 honda piston - that is what I want. If his standard 110 piston rings fit a 81-85 - that is not what I want. I thought I was pretty clear in what I was looking for.

Hmm, OK, interesting response.

Well, the other direction I could point you in is contacting Shortline10 he deals in a lot of 110 motors and may have the OEM rings for your piston.

[Micahdogg]

I'll send him a pm - thanks for the heads up.

[yaegerb]

And if Shortline10 doesn't have them I reached into my bag of tricks and found this...call either of these guys, they have the std. ring sets in stock.

Part Number: 13011-943-004

1. Action Motorsports - 208-522-7759
or
2. Western Hills Honda - 513-662-7759

[Micahdogg]

Really? Even though the part # shows discontinued, they have NOS?

[yaegerb]

Like i said, my bag of tricks. ;)

This isn't my first rodeo, over the years I found ways of finding discontinued parts. Hope they can help you.

[Micahdogg]

That is nice of you...thanks!

[Micahdogg]

Use the right plug yall. This one was too long, the correct one has less threads.

http://i191.photobucket.com/albums/z84/Micahdogg/DSC04469.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04470.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04471.jpg

Piston just looks bad, it still wants to do work though.

[Micahdogg]

Wellz, got a Vesrah top end kit and two new shindy valves and will try lapping them in tonight. Cylinder was within wear limit for standard size so I'll hone it and put a new standard piston/ring kit in from Shorttrack (won't be much more than those standard rings). IF the head goes good, I'll get the carbide bits and sanding rolls out to give er a little port/polish. From what I've read, the guide bosses have a lot of meat that can be removed.

I've got another strong runnign 79 ATC110 and this one was the beater '79 so i'll see if I can make this one the "fast" one :)

[sledcrazyinCT]

There could be a lot of 110 motors with bent valves! I downloaded a manual that was an aftermarket clymer type and the damn book has the wrong plug listed - it is not supposed to be a long reach plug but that what it tells you to use.

Unfortunately my great running motor had a long reach plug half way threaded in and when I noticed it I double checked the book and it said the plug that was in it was correct so I threaded it back in fully MISTAKE!

[Micahdogg]

Started porting the intake:

http://i191.photobucket.com/albums/z84/Micahdogg/DSC04473.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04474.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04477.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04484.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04486.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04487.jpg

[Micahdogg]

Got the exhaust done, cleaned up the chamber, lapped valves again, put new valves in...she is ready to install. The exhaust looked REALLY restrictive. I couldn't get a good before pic from all the carbon, but there wasn't much room between the guide boss and floor originally. I would have liked to go over the chamber one more time too, but at least it looks better now. I need to be riding this thing on Friday.

http://i191.photobucket.com/albums/z84/Micahdogg/DSC04481.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04492.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04493.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04482.jpg
http://i191.photobucket.com/albums/z84/Micahdogg/DSC04490.jpg

[Micahdogg]

Well...I'm riding this thing now.

Got it together a couple days ago and it fired right on up. It idles nice, has good innitial response, but runs kinda sluggish in the midrange. If you roll into the throttle easy you can get it to accelerate, but otherwise kinda cuts out.

I checked the points last night and they were out of whack. I adjusted the baseplate and points themselves, in addition to cleaning them good. That didn't help much. I moved the baseplate forward and backward and it never got better than in the standard position.

So now I'm off to poke around in the carb. I had this carb apart about a year ago and it looked really good then (and hasn't been ridden much since). The only other thing I'm wondering about is the screen behind the petcock - didn't even know that was there until looking at the manual.

I also put a new uni filter on the stock assembly, with airbox. I just don't get it. I think this thing wants to run good, but it just isn't right now. OH, it does run better with the choke pulled - so that would mean Lean right? It kind of acted like this before the valve got chucked so I'm thinking there is a mechanical issue still unresolved (hopefully in the carb cause I'm running out of places to look!)

[oscarmayer]

the sluggish is the porting. sorry but if you don't know how to port these things doign so casues them to run worse than stock. the msot you shoudle ver do w/o a flwo bentch or 20+ yrs of porting expirence is port match the intake and head and exhaust and head no more than 1" into the port. Any more and you run a big risk of causing performance loss just like your expirencing. I imagine if you dynoed it against a recently redone stock not touched you will se your pwoer numbers lower.

on the choke stuff, yes it's runnign lean, you need to adjust the mixture screw, then possibly the jetting. also if the jets are clogged it coudl cause this as well. Did you proeprly set the valves to .003-.004 intake/exhaust?
Did you rebuild the carb itself?

[Micahdogg]

I would wager that the head porting isn't causing this. I've already adjusted the mixture screw and idle. Only takes 2 minutes of adjusting to fully range your options out. When I had the carb apart last year it didn't look too bad. I could see through the jets, but shot a stream of brake cleaner through them anyway. And the valves are .005...they sound pretty good and are much tighter than they used to be.

Have you had any luck dropping the clip in the needle to get a little more fuel in the mid/top end? Or do you just go straight for the main.

[oscarmayer]

needle only works for up to 1/4-1/3 throttle. after that it's all slider and main jet. adjust the needle will only help with low end-mid stuff. if he has it in solid mid range, then there's somethign going on with flow. that was why i was touching on the porting.

[shortline10]

Drop the needle 1 clip at a time and if that doesnt do it bump the main jet up a little .

[Micahdogg]

Thanks for the tips guys. I found a problem with the "flow." One of the screws that holds the choke blade was gone! The other was half way out. I sure hope that screw dropped out before the rebuild.

Anyway, I pulled the carb, cleaned everything out, put new screws with loctite in the choke blade. It doesn't seem much better?!?!

I got the compression gauge out and it only produced 125 psi with the throttle wide open. I did take a little metal out of the combustion chamber to get rid of all those scars (hopefully that was all from the choke screw), but I only took enough to smooth everything out. I can't see that doing it.

I'm wondering if the headgasket is leaking. I installed the head, then tried to put the cam and gear in. I didn't realize the gear was 1mm bigger and had to go in first, so I pulled the head, put the gear in and torqued it back to 175 inch-lbs. I didn't have a warm fuzzy feeling about that, but it didn't fire so I hoped it would be ok. Maybe not.

I guess I'll pull the head again and go after the head gasket. Anyone know how I can get another headgasket in springfield, IL in one day?!

P.S. Oh yeah, it's got a #85 main, #35 pilot and needle on 3rd clip. I left it alone for now.

[shortline10]

135 psi is OK. Make sure their are no leaks at the filter box and that its connected to the long tube in the frame. Also the drain on the air box should have the plug on it. The 110 needs allot of intake pressure to run right and if it needs the choke to run your air box isn't sealed up properly.

[Micahdogg]

The boots are pretty tight on the carb, but there is no drain in the airbox (I could see the hole). I also not only DON't have the long tube in the frame connected, but I removed the 90 degree rubber boot from the box to let more air in - thinking it would help with the porting.

I will be amazed if choking the airbox up fixes all this...but I'll take your word for it. How do these 110's run with open air filters just clamped to the carb?

P.S. What is the lowest compression that these will "run" at?

P.P.S. Just re-read what you said and it actually makes a lot of sense.

[shortline10]

100 psi to run OK. You won't find a 110 with a open filter and stock Carb unless its been re jeted . Like I said they need allot of intake back pressure. I have been messing with Honda's for over 28 years and theirs not much that I haven't seen._

[Micahdogg]

What is typical psi to see out of a stock rebuild - is the 175 that the manual says a little lofty? Also what would you change in the jetting to make up for a lack of backpressure (planning ahead in case I can't get it choked up enough?) Starting to think the high flow Uni filter was a waste of time - possibly along with the super awesome porting.

I really appreciate all the help.

[Micahdogg]

Ran home at lunch and reinstalled the 90 degree boot into the frame/airbox and put tape over the drain plug hole. It seemed to run better. It still has the low rpm sputtering, but half throttle and up felt pretty good. YOu could hold it WOT and it pulled to the top well. I couldn't find the long tube that runs inside the frame though.

[oscarmayer]

try re-jetting then see what happens. i woudl look at pumping up maybe 2 jet sizes to a 95 jet and see what happens.

[shortline10]

Now your seeing the light :lol:



Ran home at lunch and reinstalled the 90 degree boot into the frame/airbox and put tape over the drain plug hole. It seemed to run better. It still has the low rpm sputtering, but half throttle and up felt pretty good. YOu could hold it WOT and it pulled to the top well. I couldn't find the long tube that runs inside the frame though.

[Micahdogg]

Now I just have to prove that my awesome porting was awesome and worth all the time I wasted.

Oscarmayer - where are you getting jets for these?

[Micahdogg]

Really getting frustrated. Moved the clip one notch down and it made almost no difference. It still starts easy, idles like a rock, sputtering mess in midrange, then half throttle up is good.

I changed plugs and put fresh gas in since it was low - no change. I'll replace the fuel lines and filters next I guess. I can't find the snorkel for the inside of the frame so I'll just make a tube I guess. I just hate this troubleshooting process.

The worst part is that I know very little about this thing and have only ridden it a few time before it gave up the ghost. It has always run rough so it is hard to tell the difference from pre-existing conditions vs. what I've been messing with.

Maybe it's just got a weak spark?

[shortline10]

If its a points motor replace them.

[Micahdogg]

It is a point motor. I've adjusted and cleaned the contacts, but I guess they could still just be bad?

[shortline10]

Yep a bad set of points will act like a Carb issue.

[Micahdogg]

Big updates.....

I swapped the points over from a known good running machine and wouldn't you know it - suddenly it runs good without sputtering in the midrange. :) I was giving it some full throttle romps and can tell the difference in the porting. It's snappy off the line, the midrange is lazier, but the topend is stronger. It gained as much on top as it lost in the midrange. I didn't really have a goal other than to increase HP and it feels like that certainly happened. I've got another normal running 79 110 and this one will trash it now.

Off to order some more points! Thanks for the help guys.

[Micahdogg]

So I ordered some points and a #88 main jet. Swapped the points and before I could even start it, the petcock started leaking. Enter 4 days of tinkering with the petcock only to decide that it was completely fubar. Ordered another brand new carb from Ebay and it showed up tonight. Before I even install it, I check the jets. #78 main and #33 pilot. Yikes.

I installed the #88 main and put it in as is. Adjusted the air screw and idle as good as I could and the midrange has some goofiness going on again. It's not quite midrange, just before - and only when you get aggressive with the throttle. I'm thinking it's the #33 pilot jet just not being big enough. Overall it is running better, idling smoother, pulling better on top end and not leaking gas anymore. I just need to get it to pull smooth through the entire rpm range.

Oh, I lowered the clip to the 4th and 5th spots and it felt worse each time - so it's back in the 3rd spot.

[Micahdogg]

Time for another update. My carb jetting was 32 pilot, 88 main. Not 33 pilot. I stumbled on a 34 pilot to put in, made no difference. Retarded the timing via baseplate as much as it would allow - now it runs smooth and pulls even through the entire rpm range. FINALLY. SO yesterday i get it out to show my friends how great it is running and now it no longer runs good. Fires up and runs fine, but seems like when it gets good and warmed up - maybe 5 minutes into the ride - it just dies. I can't tell if it's a function of the heat, or just riding it fairly fast - but it will peter out and be dead. Give it a minute or so and it will refire.

Plug looks good, not really fouling out, not wet, gets good spark holding it against the head. I lowered the clip to get it richer and it made not much difference.

This isn't a jetting issue and I think the spark is fine. I'm wondering if I'm sucking the bowl dry - like maybe the internal filter isn't good for flow.

[Micahdogg]

I pulled the stock filter out of the petcock and now it's all fine. I think between that plastic thimble looking thing of a filter, and the other inline filters I already had - it was just sucking the bowl dry. Rode for about 3 hours last night and it was just fine now.

[oscarmayer]

glad to hear it. i'll dig for those parts for ya this weekend. finally got somewhat settled into the new home so should be ok to find stuff.