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post #1 of 9 (permalink) Old 10-10-2009, 11:56 AM Thread Starter
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Stalling Problem

I've been reading some posts about dirty carbs and since I know very little when it comes to bikes, I want to try to avoid taking the carbs off. Now I'm assuming this is the cause of my problems.

If I don't want the bike to stall while at a stop, I have to keep the choke at least half way. I know this enriches the gas so I'm assuming something might be blocked up some where. I've bought some seaform and put in around a quarter of a bottle in with little results. (However, I haven't took it for a long ride since some one stole my plates! Just been riding on side streets, haha. I just got the police report and will have to go to the DMV on monday ) I have been putting in 93 when I fill up my tank, but after reading on here I guess I should stick to 87???

So I guess my question is, should I ride till my tank is empty and fill it up with a good mix of 87 and seaform? Also, I've read I may want to adjust the air-mix screw to 2.5 turns. Do you guys think this is enough? I really hope I won't have to take out the carbs. Although, I have a buddy of mine who said he could walk me through it so it won't be the end of the world.
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post #2 of 9 (permalink) Old 10-10-2009, 01:32 PM
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Adjusting the screws to 2-1/2 turns will help backfiring on deceleration, but not having to run with the choke on. Starting to use 87 grade gas will save money, the bike will run just fine-after you get the carb issue out of the way. Seafoam is a solvent and solvents take time to work. The more gunk there is, the longer it takes to dissolve. So it could take a day or two for Seafoam to do what it's going to do. Bad news is that usually bits and pieces come loose and stick in places you don't want (like jets). There's a cheap trick to try. Shut off the gas at the petcock, start the bike and ride it until it dies from lack of fuel. Open the petcock, let the bowls refill and repeat. Sometimes this will let the stray piece of junk clear whatever it's hanging up on. If that doesn't do it, remove the drain screws and shoot Gumout or similar carb cleaner into the bowls. Let that soak for a while and see what happens. I believe that's about all you can do until you actually have to pull the carbs and really clean them out. If it gets that far, be sure and ask for pointers-many have been down that road and can offer up some good tips I'm sure. And be sure and start adding Seafoam monthly after it's running well to prevent problems in the future

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post #3 of 9 (permalink) Old 10-10-2009, 04:08 PM
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Removing you petcock to check for fuel flow/debris is really easy too. Try everything Ironman said before pulling those carbs. From your description, it sounds to me like your idle circuits are clogged. You may be able to get some carb cleaner down the orifices by having someone hold the throttle open and blasting the hole with the straw on the can of cleaner. Do it with the bowl drains open. Seafoam works.

I have solved many driveability problems with a tank of fresh gas and a good long run using lots of throttle. Roll it on, thru the gears, then roll it off thru the gears. Do it for a half tank, maybe that'll help. If not, it sure is fun anyway.

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post #4 of 9 (permalink) Old 10-19-2009, 10:01 PM Thread Starter
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Well I tired the petcock trick and I added more seaform with a tank of 87. I rode it pretty hard once last week and tonight (It was 40F outside, not a smart idea!!!). I still have the choke half way when I ride but tomorrow I'll see how it is with the choke off. I'm thinking about adjusting the idle screw because it seems to idle at around 600-700rpms before it stalls out. Maybe this has to do with dirty carbs, I don't know. Since the bike runs OK the way it is now, should I just keep on riding it till I put it away for the winter? Will it do more damage? Also, if I decide to take the carbs out, should I wait till the spring when I start to ride again so I won't have clean carbs just sitting there?

Thanks for the help.
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post #5 of 9 (permalink) Old 10-19-2009, 10:28 PM
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Hey there, Chap. Why are you idling at 600? Proper idle speed is 1100 RPMs, so maybe you just need to adjust your idle screw to maintain 1100 RPMs at idle. That would be a simple fix. Also, if you're gonna put her away for the winter, put some seafoam in the tank, ride a few miles and when you're back home run the bike with the fuel shut-off valve in the OFF position until she dies out. This way there won't be much fuel in the carbs to gunk up. You should also keep your battery on a battery tender so it stays charged properly. (I hope you have a glass mat sealed MF battery, and not a stock wet cell). As for taking the carbs out, if you need to do it then do it now. Gunked up carbs will only be harder to clean after the winter is over.

BTW, welcome to the forum. Lots of good people here to help. it might be a good idea to create a signature line so we can all see what year your ride is and what mods you've performed, etc.. It helps others to help you out easier.


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post #6 of 9 (permalink) Old 10-20-2009, 08:14 AM
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x2 what rubyrick stated. Our bikes should be idling at 1100 rpm's and welcome to the group.

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post #7 of 9 (permalink) Old 10-20-2009, 09:17 AM
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X3! You should also pull and check or replace your plugs depending on what shape they're in. Running 93 octane for any period of time can carbon up your plugs and intake/exhaust valves etc. Also, since you've been running with the choke half on, that will contribute to carbon build up too. Add the idle speed too low and you are batting 1000 on carbon build up, which can cause the plugs to miss fire, especially at low rpms. Keep the seafoam flowing! If it were me, I would remove both pilot screws and use a can of spray carb cleaner (B12) with the little red straw and shoot some carb cleaner down into the pilot jets and see if you can get them cleaned out. Then re-install the screws all the way to the lightly bottomed out position, then count the turns back out to 2.5 turns and leave them there. If the bike is running good in the upper rpms, this might help, but I kind of feel like the low idle setting and the more than likely carboned up plugs are your main problem. If you can find the iridium NGK's stick those in there. I believe they're pre-gapped at .32 which is just right.
By the way, remember to wear eye protection when you shoot the pilot jet holes with the B12 as it will probably shoot back at you!

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post #8 of 9 (permalink) Old 10-20-2009, 09:47 PM Thread Starter
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Thanks for the advice about the winter, I would definitely follow that. I do have a MF battery (one of the first things I bought) but when I put my bike away I will take it out and leave it inside my house.

I did try to adjust the idle screw because I knew the bike shouldn't be idling that low but I thought maybe its because of dirty carbs. The only question I have is which way should I turn the screw to increase the idle???? Hopefully this should solve my problem.

Also, I will take the pilot screws out and try to spray some cleaner up there. I have a feeling once I adjust the idle everything should work out because the bike runs pretty well beyond that. I have been meaning to get new plugs but I just haven't actually gone out and gotten them.

I will try to get some pics up later but I haven't done too much with the bike. Its not in the best looking shape but for a 1991 I'm pretty happy about it.
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post #9 of 9 (permalink) Old 10-22-2009, 08:15 PM Thread Starter
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Just played around with the idle screw and took it for a nice ride today. Run much better and I had no problems at all. Thanks to everybody for the great advice!
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