1986 honda 125M

[hosscat]

I just got a 125m and at first glance it seemd to be in decent shape, but the more I look the more crappy makeshift patches I see. First off it does have decent fenders and a good tank. It is missing the front fender. The carb is in horrible shape, fuel will run out of the overflow tube, it won't idle, and some times it will rev up on its own. The kid that had it cut the muffler off so it would be louder, and the electrical system is riddled with splices and in no way is hooked up correctly.

My plans for this thing is to get it running as good as possible and leave it at some property I own a few hours from where I live. I have already got a carb rebuid kit and almost finished installing it last night ( i still need to fine tune some adjustments) and I have a temporary muffler on it. Next will be spark plug, and air cleaner (the factory box is missing). Also, is there a way to adjust the slack out of the drive chain. The manual I downloaded talks about adjusting the slack out but doesn't tell me how. Eventually I will install a new chain, and sprockets, but after I get it running better.

Thanks,

[hosscat]

well I worked on my carb again last night and it still doesn't idle right. It idles high, and according to the manual I have I should adjust the idle with the pilot screw, which is new from the rebuild kit I just installed. Well I am supposed to get it running and then tighten the screw until it quits then back out like 1.5 turns and restart. I can run the screw all the way in and the idle doesn't change one bit. So either the seat that the screw goes into is badly scarred or I have the wrong screw, tonight I will put the old one back in and see if can adjust it that way. Any help or idea would be great.

[rdlsz24]

I've had no luck getting some of those older carbs to work right. They do the same thing you are describing; idle super high so you turn the idle down and turn in the a/f screw and then they either don't change, or it drops too much and then won't idle at all. I end up going the eBay carb route but I don't know if you will find one for your 86 as that is a rare trike.

Rob

[tri again]

After at least 20 carb rebuilds, I had similar symptoms on one.

Surely I didn't miss anything.

well, the 'w' clip that holds the main needle down inside the piston had flipped sideways allowing the needle to settle wherever it wanted to.

Not sure if the 125 is the same, but the easiest thing to check.

I also relearned that even if jets are clean or new, doesn't mean the internal passages are clear.

Not sure if it's right, but I usually blow thru them when they're submerged in hot water.

That made perfect sense when I had a known working carb and a misbehaving one so I could compare side to side.

[hosscat]

I didn't have time to work on it any last night, and I won't have time until this weekend, but I am planning on taking th ecarb back off and double checking everything, kinda just starting over from scratch.
I am also hoping that when I get the carb running right it will reduce the amount of smoke this thing makes. Right now it smokes pretty bad, but looking at the plug it doesn't seem like it is about to foul out from oil. And it normally doesn't smoke bad right when I crank it but after a minute or so. So I'm hoping that it is from the carb flooding and it's gas smoke, not that it is from the oil getting warm and thinning out and being pushed by the rings.

[rdlsz24]

I haven't bought an ATC yet that didn't need a top end rebuild. I'm guessing you will find the same if yours is smoking

Rob

[hosscat]

Well I found my idle problem. The throttle cable was adjusted as far as it would go, so basically I was idleing at about 1/4 throttle. I have it where it sounds fine now but the carb overflow tube at times will drip gas, does that mean that I have my pilot screw in to far or not far enough? Also where is the best place to get a top end rebuild kit. It still smokes, but oddly enough at times it won't smoke to bad and at other times it will smoke like a train. I assume my rings are just worn.

[atc350xer]

Won't sticking valves make it smoke intermittently as well?

[thestud25]

Yes, smoke usually indicates that you need rings or a rebuild. Your carb overflowing is probably due to improper float level, or the needle not "seating" all the way. Put up some pics of the trike!

[bigworm626]

Kid I bad for you, For the electrical, on a 125M thats the worst because it's an entirely different animal. There such a pain in the rear. I wish you the best of luck on that bad boy.

[hosscat]

I was wondering about sticking valves, anyway I will put some picks up sometime.

[hosscat]

I need a new recoils spring for my pull start, where can buy one, and are all models the same? Now that I have it running a bit better I would like to be able to crank it without pushing it off.

[hosscat]

I'm pretty sure I have a valve that sticks, Yesterday I cranked it up and ran it for like 10 minutes, it idled fine, reved up fine, everything was great, then I shifted into neutral and for some reason the idle changed and it started to rev up and like a switch was flipped it started smoking like a chimney.

What all do I need to go in and fix this, will I need new valve springs, new valves, head gasket, etc. or can I just take it apart and probably clean the 24 years of carbon build up off, reassemble and expect it to run better?

I want to have everything I will need, but I don't really want to buy a bunch of stuff that I don't need.

[mullet]

Also, is there a way to adjust the slack out of the drive chain. The manual I downloaded talks about adjusting the slack out but doesn't tell me how. Eventually I will install a new chain, and sprockets, but after I get it running better.

Check on the right side of the bike. Where the foot break lever goes into the frame, there is some hardware attached. Loosen the bolt, and you can pivot the chain tensioner which is located on the opposite side. Not positive if this is how you adjust it on a 125, but this is how its done on a 110, so it might be the same. Good luck!

[0GravityMX]

you adjust the chain at the rear axle. loosen the 4 carrier bolts and then tighten the 10mm adjuster nut untill the chain is tight


BTW: mullet that way of adjusting the chain your talking about is for 83 and older 110's/90's

185/200/110 (84-85 )and 125m use the rear axle adjusters