Rear Wheel Spins In Neutral (On The Stand)

[bdholsin]

I managed to breathe a little life into my bike this weekend. Got it started (we'll go more into that in a minute) while it was on the center stand. The bike was clearly in neutral but the rear wheel was spinning a bit...not real fast but it was turning. Seems like the clutch was dragging a bit. Is that normal???

Now, I put the K&N pod air filters on it (the rest of the carbs are stock for now). It wants to run for 2 or 3 seconds on full choke before dying. I was able to roll the throttle a bit and goose it but not too much. I actually took it up and down my driveway before it completely died on me. I'm guessing that I need bigger main jets as the increased airflow is causing a lean condition. Am I going in the right direction here? I have made an order from Mike's for one size bigger main jets. I also know that I'll have to fiddle with the idle mix screws as well. Just need to know that I'm thinking correctly here.

Thanks.

 

[Travis]

The rear wheel spinning in neutral when it's on the center stand is common on a lot of bikes. Has nothing to do with the clutch because it's fully engaged when the transmission is in neutral. It's just from thick (sticky) oil in the transmission on the gears and shafts. Don't worry about it especially if the bike hasn't been ridden in a while.

As far as your carbs, was the bike running well before you put the pod filters on?

 

[bdholsin]

It wasn't running when I got it. The PO claimed he was riding it earlier this summer and that it just needed the valves adjusted but I call horse$hit on that now. Fortunately I only traded a shotgun for it and it is in quite good shape. Oh yeah, I've cleaned the carbs about 3 times to be sure they are clean. I'm so close to getting it running I can almost taste it.

 

[Travis]

How are you cleaning them? It sounds like you still have clogged pilot jets.

I dip the carbs, then use lots of the carb cleaner and compressed air. Those little passages don't always come clean when everything else seems totally clean.

The PO may have been running it earlier this summer. It doesn't take long for gas to go bad in the heat and clog the pilot jets.

 

[5twins]

Being off a size or 2 on the mains shouldn't cause the bike to up and die. Yes, it will run lean but mostly in the upper RPMs, not so much at idle. Having the mix screws set wrong can make it stall or not idle. Set them to the factory spec for your model to start and fine tune from there. Pods alone aren't a radical mod. Combine them with other things like a freer flowing exhaust then, yes, some jetting changes will probably be needed.

 

[bdholsin]

I'm cleaning them by (one at a time) tearing them completely down. Removing all of the jets, floats, and slide. Using carb/choke cleaner to soak them and compressed air (aggressively) to blow out all of the passages.

I had the mix screws at 3 turn out but that wasn't working so I brought them in to 2.5 turns out and that was when I had luck with getting it started. One item of note...I was having trouble with the right carb leaking from the main. I have now replaced the float needles with brand new ones. I can put it back together and give it a try if you think it would be worth my time. I'm down to about 15 minutes to have the carbs off for work.

5twins - I have read, re-read and re-read yet again the carb guide that you had pointed me to about a month ago. I've followed everything to a "T". Just want this big 'ol girl to breathe. My wife is having doubts about my mechanical aptitude with this thing (I'm educated as a Mechanical Engineer). I seem to be chasing my tail a bit here and starting to question my own methods and techniques.

 

[Travis]

If the carb is overflowing, it won't run right..

When you hold the pilots up to the light, you can see a perfectly round hole right? Are you removing the mixture screws when you do your cleaning? Is the little o-ring and washer still under the spring?

These are BS34s right?

 

[5twins]

Yes, I think he has an '83 which would have the late model 34s w/ plastic floats. How about the float heights? These carbs can be very picky about that. Some other things that need to be right on the 34s are the o-ring on the float needle seats and the rubber plug or cap over the pilot jets. And the o-rings on the mix screws that Travis mentioned.

It sounds like you've done a proper cleaning. Just make sure carb cleaner squirted in the pilot jet hole can be blown through and exit from the cluster of small holes in the main bore by the butterfly plate. That's the idle circuit fuel delivery path. A clean jet by itself means nothing if the fuel/air mix can't get delivered into the main bore.

 

[5twins]

And here's what you should find on your mix screws .....

..... a spring, small washer, and small o-ring. The screw won't seal and meter correctly without that stuff. The o-ring is 1mm thick X 3mm I.D.

 

[bdholsin]

And here's what you should find on your mix screws .....

..... a spring, small washer, and small o-ring. The screw won't seal and meter correctly without that stuff. The o-ring is 1mm thick X 3mm I.D.

Now that you mention it I DON'T have the small washer and o-ring. This could be a BIG problem. I will rectify this ASAP.

Yeah, I have the 34's. They are indeed moody.

I measured the float heights and they are measuring the same from side to side. I've also taken a measurement from the float bowl with clear tubing and they are pretty darn close.

When I clean I am indeed removing the idle mix screw. But as I mentioned earlier, the o-ring isn't present. I can see light when I look through the pilots. They're squeaky clean.

Going to have to wait until I get the mix screw kit from Mike's. Just made the order after reading this so we'll see how quickly it can get here.

Thank you gentlemen.

 

[5twins]

Take a close look down into the mix screw hole. The washer and o-ring may be stuck down in there right at the bottom. You may not see the o-ring because the washer covers it. The washer may blend in with the rest of the hole and look like part of it.

 

[bdholsin]

Ok, I'll take a peek as soon as I can. Much appreciated.

 

[Travis]

Yep that happens all the time.. I take a sewing needle and bend just a couple millimeters of the tip to make a little hook to use to pull them out. Sometimes it takes a few tries to hook them.

 

[bdholsin]

Well, I yanked the carbs off this morning and took a very close look...even used a flashlight. The washer and o-ring is most certainly, without a doubt not present. This certainly could explain my difficulty in getting it to start. Or at the very least (in light of my recent minor success in getting it started) why it won't keep running. I have the idle mix screw kit coming from Mike's and it should be here on Thursday.

Dang, I'm getting good at pulling these carbs. Only took me about 5 minutes to do it today.

Thanks guys. I appreciate all of your advice, guidance and patience.