Help getting my bike running

[allanrps]

When you sprayed through, did you visually ensure that cleaner spayed freely out of the idle mixture hole and the three holes above the throttle plate?

Yepper, made extra sure. And then I cleaned the spray out with WD through the same hole. I'll double check later though.

When I first dunked the carbs in chem-dip for an hour, I left the butterfly seals in because I hadn't gotten there yet. When I took the out, they looked fine though. Apparently the new chem-dip formula isn't very strong. I can imagine that might limit performance, but I wouldn't think that would inhibit function.

 

[xschris]

There is a tiny hole in the float bowl that needs to be clear. If you spray carb fluid in the top hole and nothing comes out the bottom hole it is plugged. High compressed air is the only way to really clear them out good.

 

[allanrps]

ooh, that could be it. I don't specifically remember spraying that one.

 

[unitedhow]

This helped me a lot
http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

 

[allanrps]

That is a really nice guide united, thanks for sharing it. Brushed over it, and looks like I covered all of what was included, except maybe those holes in the float bowl.

 

[allanrps]

Good news! Those holes in the float bowl were clogged on one of my bowls. Bad news is I sprayed carb cleaner all in my eye because I was being stupid. I dumped them in chem-dip and I'll try running a wire through them when I pull them out. Looks like the idle mixture and the choke go through that hole, so that's just the thing I want to see not working. I'll double check the rest of the idle circuit to make sure, but I don't want to get near that spray stuff for now. When the PO started the bike up with his carbs though, it ran on one cylinder at first. Shouldn't this have still started up on one cylinder then? Or is there another problem?

 

[allanrps]

She lives! Thanks Chris, you were right on about that hole. Just started her up. Needed a little starter fluid to get going at first. She came in at 6k rpms on full choke. After dropping her to half and no choke she was starting to calm down, but then I saw there was gas dripping all over the floor... didn't tighten the drain plugs and one rattled loose . Tightened those up and wheeled her outside of the garage and went at it again with a quick spray of starter fluid. Again came in at 6k revs and sat there for a good long time, and then started to come down to a steady idle. Of course, before it could settle, I saw smoke coming from the engine and freaked out and killed her. Tightened up the header studs (probably need to dremel those another mm or so), put on the filter, and went at her again. Came in at 6k, then I tried to go half choke but accidentally dropped the choke and she cut out. Kicked her a couple more times and I think I flooded her. Also possible that the float bowls were empty. I thought if I left fuel hose in the fuel bottle, the carbs would suck the fuel in. Upon further consideration, don't think it works that way....

So, never actually got to let her just sit at idle, but seems to me she'll do it. I'm kinda scared that there's something wrong in the engine that'll cause the thing to burn itself up or something, cause I haven't been in there and don't know any better. PO started it up though, said it ran all last summer, so I guess that's a groundless concern.

I'm going to try to start her up again tomorrow, this time without the fluid. I want to suit her up and try to ride her, but my tank is being vinegared right now . Probably should put the front brake on first anyway....

 

[unitedhow]

Congrats!

If the revs stay that high it's probably running lean.

Check that your charging system is working before you ride it too far

 

[allanrps]

haha, yeah, that's a good idea. Thanks, I'll definitely do that.

Thanks for the tip about it running lean. It seemed like it was going to settle down, I just never let it get there. We'll see tomorrow though. It probably is pretty lean, judging by the jetting numbers I've been reading. Also, I screwed the idle mix screws back to stock, I'll screw those out a turn or two.

 

[allanrps]

Just went and started her again and she was idling really high. never got below 4k, after I turned the idle mix screws at 5 turns. The exhaust was also popping. I'm googling it right now.

 

[allanrps]

I don't get it. Now, no matter how I have the idle screws set, from 3 to 6, whether choked or not choked, it runs right up to red line the second I kick it. Still researching for a solution.

Maybe something in the carbs is slightly blocked? I blew everything through with carb cleaner when I cleared out that hole in the bowls, so I wouldn't think it would be a problem, but maybe?

Maybe I need new boots? Mine look pretty decent, but may be it...

 

[xschris]

I would check your diaphragms for holes or if the rubber is loose and spins on the slide. Never go more that 4 turns out on the idle mix screws. If 4 is not enough then you need a bigger jet. Have you synced them?

 

[xschris]

I don't get it. Now, no matter how I have the idle screws set, from 3 to 6, whether choked or not choked, it runs right up to red line the second I kick it. Still researching for a solution.

Maybe something in the carbs is slightly blocked? I blew everything through with carb cleaner when I cleared out that hole in the bowls, so I wouldn't think it would be a problem, but maybe?

Maybe I need new boots? Mine look pretty decent, but may be it...

You need compressed air. Carb spray has very little pressure behind it. 125-150psi is what you need.

 

[allanrps]

Nope I haven't synced them. Thought you needed to have a somewhat steady idle to do that? Thanks for the tip about the mix screws. I was just recalling some thread here where someone said their final jetting had the right screw out 6 turns and the left 4.5.

Seems to me from what I've been reading that I have a serious air leak somewhere. I don't think its the carbs being plugged, because it was eating up gas fast. I would blow it out with air, but I don't have a compressor. Just ordered new boots by the way.

Oh and the diaphragms are brand new, fit perfect.

 

[xschris]

Make sure the hole in the slide is facing the motor.

 

[allanrps]

It is, I made certain of that.

 

[allanrps]

Good news! I started it up tonight. It started on the third kick and idled at 2k on full choke. Wasn't allowed to get her warmed up enough to pull her off the choke. Tomorrow I'll play around with the idle mix screws and try to sync the carbs if I've got long enough line.

After having a nightmare about the butterfly valve screws coming loose leaving the throttle wide open and making the motor eat the screws, I decided not to touch the thing again until I got some red loctite, which came in yesterday, on those. I ran a wire through the front brake hose and cleared out a bunch of yucky stuff; after that it was 5 minutes to bleed the brakes. I noticed that the throttle was open probably 1/4 when I hooked the carbs up to the throttle cable, so I adjusted it to be just shut. 1 problem down. Got the carb boots today, so I put those on. 2 problems down. Started up easy and, to my untrained ear, sounded just right. I just got finished vinegaring the tank (included shaking hardware out of the hole for 2 hours. After flash rusting for two hours it didn't look much better than when I started ) so I'll probably put that on tomorrow and see if I can't ride the thing.

I've got the materials to upgrade the charging system to a permanent magnet alternator and to install a dual front disk. I'll put some miles on the thing first, then go for those. I'll probably end up selling the dual disk stuff, but I'll try it out and see how it feels first. Other prospective upgrades are led brake lights, a 50/60 watt halogen headlight, a pannier rack, an air horn (hopefully I'll put an air compressor where the starter motor is, but it may be too hot), and some new paint.

Thanks everybody for the help, I'll be back tomorrow with another update.

 

[allanrps]

When I started it this morning it kicked over after a couple kicks and then idled at 2k for a while with the choke on, then died. When I would turn the throttle with it at idle, it would go up to 3 or 4k then sit there and very slowly come down. When I came back to it in the afternoon, it was difficult to kick the first time, and after that I couldn't get it to start without the electric start. Same deal with the idle, except it wouldn't hold idle for 10 seconds without me on the throttle. I tried adjusting the idle mix screws and throttle adjust screw, but I couldn't detect a difference It just got more difficult whatever I did to it until I couldn't kick start it. Then I e-started it and got the same behavior as before. I'll read up on it and try again in the evening, but it's raining now.

 

[xschris]

What do the plugs look like?

 

[allanrps]

Just took it for a ride! I got it idling at just under 1500 rpms and reacting to the throttle pretty quickly after fiddling with the throttle adjuster and idle mix screws. Got it idling nice, then I put the tank and seat on and tried to ride it. Dropped the clutch and stalled it first thing. Went at it again and took off. It really wasn't to difficult to control the thing, but the clutch will take some getting used to. I couldn't change gears, but I wasn't trying to hard. Took it around the block a couple of times, then I stalled it at the top of a hill on a slight incline. I tried to put it in neutral, but I just couldn't get it to switch. I feel like somethings got to be weird about the transmission because I couldn't get a feel for what I was doing at all down there, but I've got no experience with this anyway. I got in neutral with some difficulty before. I ended up roll starting it down the back of the hill. Then as I tried to turn around at the dead end, which I had just done twice before, I stalled it in the turn and laid it down. I dripped some gas, but picked it up pretty quickly and the only damage I noticed was that I had bent my shift lever pretty bad. I bent it back and again tried to find neutral, but I still couldn't get it. So I pushed it up the slight hill, roll started it down the back end, and drove it home. I was able to put the thing in neutral in the driveway after some work. Not sure if there is something wrong or if it's just that I don't know what I'm doing, but the shift lever doesn't feel reliable. I'll ask the PO about it.

The plugs were pretty black, but that's understandable I'm assuming since it was running mostly on full choke before