110ATC with Low Compression, will not start

[Blazer]

Hi Everyone,

After selling my 185s about a year ago, I finally took the plunge on another project.... an 82' 110ATC! The previous owner said it wouldn't run after being in storage for a couple of months, I'll find the true story once I dig into it a bit this weekend! As complete as it is, it was a good deal for a 100 bucks! I look forward to talking with you all as I bring this thing back to life. I'll try to post some pics tomorrow.

[dcreel]

They are really addicting aren't they? Can't wait to see some pictures of your new trike.

[Blazer]

As Promised, a couple photos of the 110. So far, I have determined that it is getting a good spark at the plug. Upon inspection, I noticed a goofy looking (non OEM) carb setup. Does anyone recognize this? It has two brass adjustment screws that face the side and the petcock is part of the carb assembly. I sprayed starter fluid in the carb and directly into the cylinder and tried to pullstart multiple times without it ever igniting. I could feel some compression while pushing the bike in first gear, however I am not really sure what constitutes "enough".

If anyone has some advice on this carb, i'd appreciate it. Otherwise, I'm off to do some studying with the search function!

http://i148.photobucket.com/albums/s10/Bullet0405/110ATC/th_102_1543.jpg (http://s148.photobucket.com/albums/s10/Bullet0405/110ATC/?action=view&current=102_1543.jpg)
http://i148.photobucket.com/albums/s10/Bullet0405/110ATC/th_102_1545.jpg (http://s148.photobucket.com/albums/s10/Bullet0405/110ATC/?action=view&current=102_1545.jpg)

[Blazer]

Just found an Ebay link to the exact carb mine has, but much nicer photos:

http://cgi.ebay.com/ebaymotors/NEW-Honda-ATC-110-125-ATC110-125M-Carburetor-Atv-Carb_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQh ashZitem5ad2c5b29eQQitemZ390083228318QQptZMotorsQ5 fATVQ5fPartsQ5fAccessories

[Blazer]

After doing some reading, I believe that I need to check my valves and timing. Seems like it should pop at least once after having starter fluid sprayed directly into the cylinder. While pull starting with the airbox off, I could see some of the starter fluid shoot out of the carburetor, and could hear some air noises. Is this indicative of the valve/timing?

I'll post my results when I get a chance to check it this weekend.

[Blazer]

Got a chance for a compression test today - 60psi. I then squirted some oil into the cylinder and the pressure rose to 90psi. Seems I have worn rings/piston/cylinder. I've never done a rebuild before, do you guys think I could just do a top end rebuild? If anyone has good links for parts, I'd appreciate it.

[Blazer]

When I disassemble the top end, what obvious signs should I look for to determine that it is the cause of my low compression? I have a micrometer I can use, I'm just not sure where to start. I'd appreciate some advice from someone who has done this before, as this is my first time.

[litebulblsc]

First just disassemble it enough to check the timing and valve clearance.

[Blazer]

I checked the valve clearance last night and it seemed to be within spec. The timing seemed a bit delayed, So I advanced it so that the CDI point would make contact when the flywheel markings were aligned with the "F" just before TDC. Still no combustion with starter fluid, and still have 60psi compression. I'm pretty confident that I've got a problem with the piston/rings/cylinder. I'll let you all know what I find in a few days once I disassemble it for inspection.

[Lukeatc185]

check to see what kind of shape the rings are in. if there in ruff shape. replace the rings. if the rings look decent. then you might need to bore out the jug and get a larger piston. if it all looks good then the guy might have installed the rings incorrectly. thats after you rule out timing 100%.

[Blazer]

I pulled the cylinder and cylinder head assembly today. I'm a novice when it comes to this sort of thing, so I could not spot anything obviously broken or wrong. Some of the gaskets were in pretty bad shape. Some of the cylinder head studs had quite a bit of rust, indicating at least a bad seal in that area.

I inspected the piston and rings, and even installed it into the cylinder (off the engine) it seemed to fit in snugly and have some resistance to pushing it manually. I didn't notice any major scoring or damage to the rings/cylinder, however the manual stated that the 2nd ring should have a wedge shape to it, and both of mine were perfectly flat. Could that be the problem?

A friend suggested to pour a little oil on the cylinder head while upside down to see if the valves had a leak while closed. When doing so, I did notice a slight leak as the oil would ever so slowly drain out through the valves. I can only imagine this being worse when under pressure.

I downloaded the 90/110 Service manual from the "world class help" section, however it referred to the "General Information" section for the section on engine parts inspection/rebuilding. This part was not included in the pdf I downloaded. Does anyone know where I could find this?

I appreciate all your comments. Even though I'm looking forward to riding this thing alot, I am having fun learning how to rebuild these engines. Its kinda tricky when you don't have a mentor to show you some of the finer points, but learning the hard way is still learnin! :D

Since the cylinder and piston look ok (minus the one ring that wasn't the correct profile), I'm thinking I may have had bad gaskets or a slight valve leak. If any of you have some ways to individually test these parts, I'd greatly appreciate it.

[Blazer]

I found a good manual. It stated to fill the cylinder head with oil and then blow into the intake/exhaust ports to check if there was any leakage around the valves. Sure enough, with 30psi, I had all sorts of blowby on the intake valve. Hopefully I'll have some new gaskets in by the end of the week, and will try to get this valve to seat properly.

[Blazer]

Could someone give me the rundown on how to repair a leaking intake valve? I also have alot of carbon deposits on the inside of the cylinder head and top of piston. What is the best way to clean all of this off without damaging/scoring any of the parts?

[rdlsz24]

I use a wire wheel with a power drill. Takes off the carbon and doesn't mess up the head or valves as long as you don't go crazy.

Also, that 110 is a second gen (83-85). You can tell by how the seat wraps around the tank and the square headlight.

Rob

[lndy650]

if oil is leaking past the valve then the valve is shot! buy 2 new valves and get a shop to do a 3 angle job or get some lapping compound and lapp the new valves. a lot of times its the valves rings rarely wear enough to loose that much compression.
just google valve lapping

[lndy650]

heres some valves...
http://cgi.ebay.com/ebaymotors/Intake-and-Exhaust-Valve-Set-Honda-ATC110-ATC-110-79-85_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQ hashZitem5ad359fb2dQQitemZ390092946221QQptZMotorsQ 5fATVQ5fPartsQ5fAccessories

[Blazer]

Thanks for the info rdlsz24 and lndy650, it is much appreciated. I'll order some new valves and gaskets, and be on my way! I'll post my results when everything arrives!

[Pafrig]

are the valves or valve seats pitted? if so, make sure that there is No pitting before you re assemble. Btw, make sure theres no fine silt anywhere.

[Blazer]

I lapped and installed the new valves and reassembled the engine this past weekend. After doing some final checks I did a cold compression test - 150psi. That's more like it! After installing the plug, and turning on the fuel, it started with only 2 pulls! It smoked pretty good for a few minutes, but is now running great with a healthy exhaust note. Even made a quick video to prove it!

http://www.youtube.com/watch?v=CYiwxTM3x4s

Thank you to all of you who assisted me in finding parts and information on how to complete this project. Total cost including the initial purchase and parts was only $170.00 :)

[MonroeMike]

Nice job on your bike, glad you got it fixed.