Rough idle.....

[krooozn]

I just bought a 2003 Honda Shadow Classic 750cc trike, it has 5700 miles on it and it is having a little issue with idling rough. When I take the choke off it begins to idle rough, backfires, pops and doesn't seem to want to take the gas....but if I put the choke back on about half way, it smooths right out. The bike had some old gas in it, but the owner said he had put stabil in it before storing it for the winter.....when I got the bike home, I checked the gas and the tank was about empty, so I put some Lucas injector cleaner in it and then filled the tank back up with fresh gas...and then I drove it for about an hour or so......but again when I took the choke off, it went right back to the sputtering and backfiring.....so I don't know what the next step would be other than to have the carb cleaned.....I was told that Hondas tend to like to run with the choke at about half....I have a friend who has a Rebel and it only likes to run on half choke.....will this hurt anything? If not...then I'll just continue to let it run that way in hopes that after a few tanks of good gas and cleaner...it may straighten out....

Any help would be appreciated.....

Thanx...Anita:AGGHH:

 

[Gorilla]

The idle jets in the Honda are very small. They will clog easily. Get some real good cleaner, hopefully someone will chime in with a suggestion, If that doesn't work then have them rebuilt. I bought a Shadow 600 and it the very same thing. Pulled the carb rebuilt it and it ran super with the choke completely off.

 

[Ol' Grey]

Japanese bikes tend to be cold-blooded, taking longer to warm up, especially in colder weather, but once fully warmed up, the choke should be able to be backed off entirely.

The choke is actually an "enrichener", pumping more fuel into the carb.

With the backfiring, popping, etc., I suspect that the bike is running lean. Since the choke allows it to smooth out, the added fuel from the choke being on might be compensating for the lean condition. But running with the choke on indefinitely is not advised as it could then create a too rich condition.

If it's running lean, it could be that the pilot jet is a bit clogged and not allowing proper fuel flow, which again, the choke might be compensating for. You could try adding some Sea Foam to every tank of gas to see if it cleans out the pilot jet (if it's dirty) If that doesn't work, it might require pulling the carb and giving it a proper cleaning.

Other causes of a lean condition could be improper air/fuel mixture or an air leak(s) around the carb manifold, exhaust pipes, etc.

 

[Reader1]

Husband agrees with Gorilla and Ol'Grey completely. You should not have to run with the choke on once it warms up. He added that you might want to try different brands of fuel additives because different brands have different compositions and may dissolve different fuel residue.

 

[krooozn]

Just a quick update on my rough idle issue.....the bike seems to be running much better since I put the Lucas Injector cleaner in it and ran it. Planning on adding some more on my next tank and maybe using a tank of 93 octane in it.....but all in all I'd say it is 85% better than it was. It no longer bogs down when you throttle up on it once the choke is off.....and before it wouldn't take the gas hardly at all unless the choke was atleast partially engaged....

Thanx for the help.....Anita :woohoo:

 

[Gorilla]

Keep at it. You might try something stronger like Sea Foam. I've heard good things about that but no personal experience.

 

[krooozn]

I did think about using Sea Foam, but when I went to my local parts store and talked with them, the guy told me that he wouldn't recommend me using it unless I have used it before. He said that if I put too much into the system it could actually damage the o-rings and gaskets in he carb....so that kind of scared me away from it. He said it was the best stuff on the market, but it was very user unfriendly as far as getting the proper amount, especially when you are talking about a fairly small amount of gas....so that is why I chose the Lucas, simply because I felt it was a safer choice.....

But using Sea Foam isn't out of the picture, but will wait until I see what running another tank of Lucas through the system does......

Thanx and if anyone on here has used Sea Foam, please feel free to chime in with some guidance...I am open to all advice.....

Anita ray:

 

[John Luciano]

I guess he doesn't sell SEA foam HUH! I ran it straight ( no Gas ) in my Chinese bike that had been sitting for 3years and left it in for a week. It stared up but I could not get it into the main jets until i pulled the carb off. Runs great now . Hummm another thing you could try is every tank put in about 2 oz of Marvel Mystery oil . i did that to my old 1100 Wing and it purred like a kitten.

 

[Ol' Grey]

Glad that you're making progress with the Lucas Injector Cleaner and here's hoping that it manages to clean the carb without having to actually remove it (and it IS possible in many cases).

Please don't be afraid of using Sea Foam at all. Am with Gorilla and John on this and have been using Sea Foam for years with excellent results. I don't even measure the amount anymore, just pour a few ounces in with every tank full of gas and go.

Each parts store guy will have their own opinion. When I spoke with an auto parts guy that I know personally, his opinion was that Lucas was excellent for cleaning injectors on cars and trucks, but for carbuerated bikes, he recommended the Sea Foam and also said that he oftentimes would use more than the recommended amount to get a higher concentration of it running thru the carb.

Another thing that can help speed up the process is that once you've poured an additive in for cleaning the carb, find a stretch of road where you can safely ride at higher speeds (60-65 mph is usually sufficient)........The faster you're running, the more vacuum is created in the intake passing thru the carb and that equals more potential vacuum pressure to help pull any crud out of the jets. You might even feel a slight "stutter" for a second now and then as the crud gets freed up, then gets pulled into the combustion chamber and then blown out the exhaust after the combustion stroke. As the carb gets cleaner, the smoother the running becomes from idle to WOT.

 

[ronchi]

drain the old gas out , add a gallon of fresh gas and about 4=6 ounces of seaform ! start bike and let run for about a minute enough time for fuel bowls to fill. shut off and let sit overnight. start up next day and take it for a good run. may have to do it once or twice. good luck ride safe be safe !!!