Running bad then good

[jjz28]

I have been having a little problem in my lower rpms where It just doesn't feel right. Well, today I went out and my bike ran the best it ever has. It was so much smoother and actually quieter (don't know how that can happen). I could slow down to like 30 on a big hill (WV hill) and take right back off in 5th no problem. Before the bike would "shudder" And not have as much power as today. I took my carbs off and bench synched and cleaned the pilot circuit and jets again the other day but It didn't help but when I got on it today, it was great! Well, I stopped and forgot to turn the petcocks back on and started running out of gas so I reached down and turned them on while ridding and the problem was back. It got louder and not as smooth but still ran good, just not like it was before I forgot to turn on the petcocks. Well, I decided to turn them back off and run out on purpose and turn them back on to see what would happen. I did that and it started running perfect again. I cant believe how smooth it is. I guess its the carbs but they have been quadruple cleaned. Any advice? Its running great now. Should I use a fuel cleaner?

[motoman]

I have been having a little problem in my lower rpms where It just doesn't feel right. Well, today I went out and my bike ran the best it ever has. It was so much smoother and actually quieter (don't know how that can happen). I could slow down to like 30 on a big hill (WV hill) and take right back off in 5th no problem. Before the bike would "shudder" And not have as much power as today. I took my carbs off and bench synched and cleaned the pilot circuit and jets again the other day but It didn't help but when I got on it today, it was great! Well, I stopped and forgot to turn the petcocks back on and started running out of gas so I reached down and turned them on while ridding and the problem was back. It got louder and not as smooth but still ran good, just not like it was before I forgot to turn on the petcocks. Well, I decided to turn them back off and run out on purpose and turn them back on to see what would happen. I did that and it started running perfect again. I cant believe how smooth it is. I guess its the carbs but they have been quadruple cleaned. Any advice? Its running great now. Should I use a fuel cleaner?

No, fuel levels in carbs are too high. Gotta be anal setting the eight floats.

[donebysunday]

E 10

Any chance your running ethanol fuel ?

[GLoweVA]

Sounds like it's running to rich. With high float levels it'll suck too much frills. When you started running out, levels dropped and it ran leaner and smoother.

[donebysunday]

E 10

Well, I decided to turn them back off and run out on purpose and turn them back on to see what would happen. I did that and it started running perfect again. I cant believe how smooth it is. I guess its the carbs but they have been quadruple cleaned. Any advice? Its running great now. Should I use a fuel cleaner?

If you are using E 10 it collects water, when you turn the fuel off it will pick up some of the water contaminated fuel, burn it up and when you turn the fuel back on you will dispense some of the contaminated fuel from the tank back into the system ( float bowls ) but the water will go to the bottom and not be used, then running good until enough contaminated fuel fills the bowl enough to pick it up and start some problems again. I'd run some Sea Foam or flush the tank and drain the bowls. JMHO

[TopCatGr58]

Hey Folks,

I disagree, because what he said was that it recently ran great first. Stopped, turned petcocks off, forgot to turn on when starting again...then turned the petcocks back on....got a little better but not as good as before. But then shut petcocks OFF, let it run out, then turned the petcocks back on and let the carbs refill....and NOW it's running perfectly again.

To me it sounds more like his petcocks are possibly not maintaining good continuous flow....when he ran out accidentally, turned on, they couldn't quite catch up to the required flow...so it got a little better but not as good as before....UNTIL he stopped and allowed them to refill before starting again, and then it ran good again.

I'd say he should check out the petcocks to make sure they are working and flowing properly. I forgot to see if standard or special. If standard, check the vac lines for holes/leaks. There's a vac. valve that can get stuck or limited in it's movement not allowing adequate flow. If special and still using the octy, it could be problematic.

A quick test would be like what you did...turn off the petcocks, run till it starts acting up and first turn the petcocks back on...if it doesn't return to your NOW perfect running....then turn it to PRIME and see if it gets better. If it then returns to perfect running on prime, then you'll know it's a LACK of fuel, not too much! Good Luck.

T.C.

[skids]

You might be flushing out some crap in your fuel valves by turning off fuel and turning on flow again. (got filters?) What also might be happening is that there is something interferring with one ore more float actions...like corrosion in the pivot axle area or floats rubbing on gasket. The pin/seat can also stick. Later carbs employ a bail to help with that. The spring action in the pin can also stick in the depressed position.

[DGXSER]

If the petcocks were not running well, it would get worse in higher RPMs, running lean and not enough fuel near top end.

My thought is that he had a float that stuck. When he ran out on accident, then turned the fuel on, a float was stuck, let the carb flood. Second time, the float got loose and shut off like it should. JMHO.

[Insomniac]

I am a newbie to this site and should not be listened to......but I have a couple cents to through into this thread.
After reading this we can all agree that intermittent problems, SUCK and are the hardest to figure out. What if the petcocks are coincidence and he has a sticking mechanical advance? He states that it would "shudder". He also says that when running well he could slow to 30mph in fifth and accelerate with no shudder. If the motor had the advance in would it detonate ie. shudder and have no power. When running well he could give it WOT and it would just pull like the motor is 'chasing' spark instead of the motor being out ran.

I quote; "I took my carbs off and bench synched and cleaned the pilot circuit and jets again the other day but It didn't help but when I got on it today, it was great!"

There I go rambling again, just food for thought.

Edit....shorten the rambling

[jjz28]

Well, I first thought about a sticking float but I trimmed my gasket on the one that was sticking (only one to my knowledge) and set all my float heights correctly. Insomniac, I was thinking maybe the coincidence thing myself. I will check the pickup wires this morning to rule them out. TC, I have thought about the petcocks too. I have a special, no octi and run on prime. I never stopped to let them fill up. I turned them off the 2nd time while riding and turned them back on while still riding when it started running out. And yes, I don't think I can get anything but 10% ethanol. I did lower my octance to 87. I was running 93 but I think the 87 may run better. I think I will check the pickup coil wires and then put in some sea foam. Also, before I did have a float stick and it was much worse of a "gurgle" when giving throttle. It doesn't run that bad this time, just a little stumble down low and still good up top after the 3500 when mains kick in and I do have filters. Thanks guys, lots of good advice.

[jjz28]

OK, I don't think the wires are broke, not that I can tell by pulling to see if they misshape. How much is the advance supposed to move revving the throttle? I can tell, I was the first one in there. All the screws had never been touched. When revving in neutral the advance don't move much at all, it does move. I know it don't have a load so it might not move much, I guess? Also the wheel on there seems to be warped a little. I saw it when turning over to start but when running you cant tell it (the little timing wheel). I am going to put some seafoam in the tank and ride it a while. How much seafoam should I use to a tank of gas? Thanks guys.

[DGXSER]

I would put a half a can or so in. I use that much on my Special gas tanks, the standard holds a lot more gas.

[skids]

My thought is that he had a float that stuck. When he ran out on accident, then turned the fuel on, a float was stuck, let the carb flood. Second time, the float got loose and shut off like it should. JMHO.

Great minds think alike.

[jjz28]

I am thinking a float too. I took it out today and it run good but not like yesterday. I put half can seafoam in. I am sitting at home now drawing a low earnings so in the morning I am going to pull the carbs again and make sure my floats are set right and not dragging. I could also take off the bottom of the air box and turn on the petcocks and see If fuel comes out couldn't I. Oh and I am not running on prime, I am running on reserve, so I could be picking up water out of the bottom of the tank I guess, or crud. Does the prime come out of the other nipples? I have them capped off and only way I get flow that I can remember is on reserve. Also, could someone give me the correct float height on the 79 special? I cant remember and there are a lot of different numbers out there. Thanks.

[jjz28]

I just took my carbs off and they didn't seem to be sticking (floats) at the moment but I noticed my float levels were low. The metal stick I use have inches on one side and I thought millimeters on the other. So I set it at what would be 27.5mm. Well that was a good bit under the inch mark. 25.7mm is just over 1 inch. So, I am going to set them again. Could this be my problem? If the float levels are too low, wouldn't that give you more fuel? Also, I lost that little brass washer that goes on the screw that covers the pilot jet, is that needed? I am going to go try and find one anyway. If anyone could help me out this morning, it would be greatly appreciated. I would like to get these carbs back on and test it before it rains. Thanks.