1985 Honda CH150D starting issues

I have a 1985 Honda CH150D that struggles to start from cold, and often will have this low, rough idle that if not maintained by the throttle, will eventually die out. I have warmed the scooter up to completely warm and still have the issue regardless of temp. I have done everything; cleaned the fuel tank, clean carburetor, spark plug, fuel filter, air filter, oil change, new belt, petcock assembly (includes new fuel screen), all vacuum hoses, carburetor mount (the rubber one infamous for failing), breather separator assembly(all new), new muffler gasket, new battery, tested the bystarter for resistance (a perfect 0.5 ohms), all fuses check out OK, and all wiring is intact and free of damage. When I start it, it takes several tries, and once i get it going, it has puffs of white smoke at first while warming up, and maybe its because its just cold outside right now, but once its warmed up, no smoke. When I pull the spark plug, its wet, but the bike only has 870 miles on the odometer. Any help would be greatly appreciated, because as you can see, I have put A LOT of money AND time into fixing this, and my woman is livid with me right now that it STILL cannot be driven. I plan to do a compression test next (waiting on 12mm adapter), but in the meantime, I'm open to suggestions. Thanks.

If I remember correctly, when I bought it, it had the same symptoms. The guy I bought it from owned his own motorcycle repair business and had a bunch that looked nice. There isn't a drop of any fluid leaking anywhere. The bike looks brand new through and through, and I have a good eye for a steam cleaned engine. It sat for years because no one could get the title, but I applied for an abandoned vehicle title; took two months to get it. In the meantime, I have been tuning it up and replacing things that rot over time, but the carburetor was supposedly cleaned by the guy I bought it from. When I pulled the carburetor to replace the carb mount, I looked it over, and it was shiny silver on the inside. My greatest concern is the plug being wet every time I take it out to check it. Its more of a watery oil consistence and not so much straight oil on the plug. By the way, when placing the carburetor back into the mount, should there be one "pop" or two to let me know it is seated in the mount all the way? I only ever felt one "pop", and the guide groove at the top of the mount is lined up with the notch on the carburetor, but it is not fitted around the notch; stops just before it. Could be a problem too. Just surprised that something with low miles has such issues when nothing mechanical jumps out at me. Thanks.

The running conditions do not change from cold to hot. Still has a rough idle, and every now and then will NOT die, but still idles very low; so low that there is a slapping sound coming from the drive belt area which I assume is the drive belt hitting something since it is loose at idle, and when accelerated, the slapping goes away. Carb settings are stock; nothing appears to be tampered with. I did try adjusting the valves by feel and sound as someone else had suggested in another thread, but I have not removed the cylinder cover to look at the valves, because it isn't leaking, so the "if it ain't broke, don't fix it" rule of law applies (don't want to get in over my head). I'm at sea level in the state of VA, and the coldest it gets here is 26 F, but lately its been in the 50s. But yeah, the scooter ran when I purchased it, and it ran about the same, possibly worse because it was colder in the mountains where I found it. It will go for a drive around the block, but when I come to a stop, it dies. A footnote, I used an Iridium NGK plug. Hopefully that won't hurt anything, but it didn't change or improve the way it ran from the get-go. Thanks.

Having oil/water in the cylinder could be a bad thing, but it would have to be a whole lot to make it not start.

I would still focus your efforts on the carb. Sounds like it's just running really rich. If you can find someone that will lend you a spare carb that's known to work well, you can swap it in and make the call. You have air. You have spark. You have fuel. Now you just need the right amount of fuel/air.

I'm betting there's an air passage that's blocked. Could be an old bugs nest, a little lacquer, or just something. Half the time I fix carbs by just taking them apart and looking for the problem. Put it back together and Voila! it works.

Take the carb off, remove every screw, and blow out every passageway with carb cleaner (use the straw) then compressed air. If you don't have a compressor, just get a can of CO2 that's used to clean computers and stuff. They usually come with a red straw that works really well for blowing out carbs. Make sure you wear safety glasses, because it will shoot everywhere.

If that doesn't do it, strip the carb to metal, boil the body for 1hr, buy a $15 rebuild kit from eBay and rebuild it.

I bet if you stick your finger in the tailpipe it will be pretty black.

The intake boot only has one ridge. One pop is all you should feel/hear.

You should post a picture of the spark plug too. Clean it off with a wire brush or wheel (or put in a new one) try and start it, then pull the plug and inspect it. (and take a picture).

Yo.

-Kevin

You could also have something simple like a sticky float valve. You won't notice it if your petcock valve is working right, but it will just flood the carb and venturi with fuel if it's not at the right height.

You can test it by putting some clear tubing on the drain valve on the bottom of the carb. Open the drain valve, and hold the clear tubing up next to where the float bowl meets the carb body. The level in the clear tubing should be at the level of the top of the bowl. You also have to supply the carb with un-restricted fuel, so take the vacuum tube that goes to the petcock and suck on the carb end of it to open the petcock.

If you get a mouthful of gas, you either have a broken petcock or you sucked on the wrong pipe. Use a brake bleeder vacuum kit if you're nervous.

If you get gas in your mouth 2x, Quit. bwwwaaahahahah.

Seriously, keep at it. Eventually you'll have that "Ah-Ha!" moment, and it will work, and you'll kick yourself for not figuring it out sooner.

-Kevin

If that works, I'll kick the dog and the cat too. I want this thing to move so bad. I have had PA-50 II's and Tomos and all sorts of other scooters that had zero power when I was younger, but the dream was always to run the CH150D and the Helix: I want both. It's optimistic- I know. Your help is extremely awesome. When I get it reassembled, you will see what I mean; this scooter looks like NEW. It's not missing a single thing. I even customized it with a really nice trunk with backrest and Electropods lighting. I will work on the spark plug next and get that picture posted. Thanks!

-Tom

The electrical connection between the spark plug cable and the boot at the plug can be corroded and you get a weak spark. The boot unscrews from the cable so clean that up. The bystarter that creates a rick mixture at cold start is often a source of trouble. Make sure the electrical connections are clean, that the gasket where the bystarter sticks into the carb is snug. You can test the bystarter by removing it and measuring how far out the needle projects. Then you connect it to 12 volts and wait a few minutes. The needle should extend some and project out further. If it doesn't move the bystarter is shot and yo need a new one.

Is the air cleaner clear? Does the situation change a lot when you remove the cover of the air cleaner?

Is the exhaust clear? Spiders and wasps like to build nests in exhaust pipes and plug them up. Poke a flexible cable into the end and see if it clears out mud or bugs or something.

There is lots of very good info in the tech tips at www.ch250.net.

Speaking of electrical, could the CDI be at fault, and if so, does anyone have an opinion on this one? http://www.monsterscooterparts.com/no-rev-limit-cdi-150cc.html

I've heard good things about the monster CDI. Another thread discuss's it in detail. I might have to pick one up as well. Let me know if do, love to hear more about its performance.

bystarter can cause this .

I checked the resistance on the bystarter with an ohm meter, and it was a strong 0.5, so that seems to be in good shape. The only things left are Kevin's suggestion of the carburetor, which I am staring very hard at, or the CDI, which has no way of being tested other than the fact that it is 27 years old and ugly compared to what is available currently. I also wanted to know the opinion of anyone who has ran Michelin S1 tires. I already have them and they are mounted, brand new, but I have nothing to compare them with. I know Continental Zippy's get a good deal of praise, but I wanted to know if the Michelin S1s will hold up OK.

I tried to photograph the spark plug the best I could. Hopefully this will do.

Looks like it's burning lean. Clean the pilot jet circuit again, poke a very thin guitar string into the holes. Make sure the float level is right. Hondas start.

Just finished up checking the rollers in the movable face, and they look good....however, when I checked endplay on the crankshaft by giving it a "push and pull" from the movable face side, it is making a little noise and has noticeable movement to it. If I had to guess, it's somewhere around 1mm or so of movement I can see. I think that is where the noise from the drive belt area originated. At low idle, it's more pronounced, but when accelerated some, the knocking noise subsides. Is there any need to adjust endplay on the crankshaft, is it normal, or should I worry? No noticeable leaking or damage anywhere on this bike; I just want to make sure before I start using it on long drives. Thanks for the advice on the carburetor and possibly burning lean (or rich) - once I decide on this crankshaft issue, I will move on to rebuilding the carb.

I have prepared a 42 second video on YouTube to demonstrate the noise from the crankshaft. Here is the link:

http://www.youtube.com/watch?v=TuavAlmfe7U&feature=youtu.be

Any advice would be greatly appreciated.

By the way, that is the rough idle I am experiencing as well.

Sounds like the belt slapping to me. When did you change it last?

You worry to much,they all make noise at idle,especially if its idling to low.I have an 85 with around 30k on it and have never touched anything on it but regular maintenance.My Elite 250 makes noise and so does my Reflex. By the way ,I have an extra ignitor box off my 250 but I'm pretty sure they are the same. I had trouble with my 250 a few yrs ago and went thru hell trying to figure it out, Carb,ignitor,coil, you name it I tried it. Turned out the exhaust had fallen apart internally. New helix muffler fixed it.

That's reassuring, Baloney. And as for my drive belt, brand spanking new Gates Powerlink 799 19 belt from ScooterDomain. It's the real deal, and that is the exact size needed. Just real loose at idle and not sure what to do about that. With the belt off, no noise, and that video I posted was WITHOUT the cover on, so not sure if the belt was actually hitting anything. To be honest, the movable face was off when I had no noise as well. One of the two is the culprit most likely, but if the crankshaft is not a concern with its roughly 1MM of endplay, then I'm a happy camper. I love this scooter even though I haven't taken it farther than one mile. This has been a dream for 20 years to own, so I'm being meticulous when it comes to examining her and making sure she will be in top form from the moment I have her entirely back together. Thanks to anyone who has any advice, and I assure you I don't shrug ANY of it off. I try all advice as long as it won't permanently damage the scooter (like using water to clean carbon deposits - too risky for me).

This guy has a drive belt that stays tight after the bike is first started and once it stops as well. That is an issue I have been having for sure.

http://www.youtube.com/watch?feature=player_embedded&v=fBHAM1am-UE

I don't know if it is normal for the belt to be loose on this scooter, or if it is something that is not doing what it is supposed to, but the belt is brand new and the correct size. Just slaps away at the low rough idle, but once the throttle is applied, it tightens up decent, but still has some jumping to it.

The belt should be loose at idle. What can happen though is if the front variator is allowed to come open when the belt is removed,as in running with no belt on it,the rollers will come out of their ramps and lock the variator in an open position causing a direct drive condition and it will stall out when you try to stop. It also will no longer open correctly and there will be no top speed.