Well…..Mailman…….have our bikes been talking to each other or sumthin?
After losing almost a month of some really good riding weather waiting on my machinist to fix my 2 carb sets, I finally caved and picked up another set of 78/79 BS38’s. Probably cost me a lot less than what my machining costs will be and figured having a spare set of good working 78/79’s on the shelf ain't a bad thing. (If I can achieve that)
I'm (almost) at the point of admitting that I might have a problem and may be in need of an intervention.
"My name is robinc and I am a carbaholic".
I had the benefit of a mental health day earlier last week so tore this set down, cleaned, replaced o-rings, new OEM float bowl gaskets, bench synced, diaphragms strong, don't even drop. No damage to this set other than a bent choke lever that I straightened. However one of the floats was leaking so ordered a couple from XS650Direct knowing I could get them in a couple days. Have since learned from some other recent carb threads lately that they are still available OEM so will get them if these prove to be inferior.
After work Friday installed new floats, reassembled and used my remote tank stand/bench top float level checker thingamajig. Funny how the level shows a little low, they are set to 24mm from the gasket surface, and are not twisted. I checked, checked, checked and re-checked. Well I figured better a little low than a little high.
Started easy, 2 kicks, idled great, revved great, butterflies moved smoothly, no binding, but (why does there always have to be a but) within 2 or 3 minutes it was obvious from the wonky hanging idle that the throttle shaft seals were leaking. Got out the carb cleaner and yup, sure enough.
Off they come again.
Looks like Mailman and I spent our Saturday the same way, in carb surgery. We should have done one of Pete's famous video chats……..lol.
I'm sure thankful for this thread by gggGary:
http://www.xs650.com/threads/carb-t...ft-butterfly-screw-removal.46423/#post-464664
that gave me the idea for my little 'Stick it’. (see post #41) Made the job of removing those throttle shaft screws easy.
You can see how these seals are deformed and cracked, really dried out and hard.
Ran out of shop time so remounted on Sunday.
Fired up easy again, couple kicks, no more wonky idle, revved up nice, but it was raining so couldn't get out for a test drive.
Due to unforeseen circumstances only worked a half day today. Normally I wouldn't be happy about losing half a day but with a bike to test drive, OK.
Fired up first kick, and continues to do so.
Half way through a short ½ hour ride, throttle shaft leak symptoms reappeared. Huh? Just put new ones in 2 days ago. (C facing out)
Bike back in shop, sprayed WD40 on right side throttle shaft end, idle increased, no effect on choke assemblies. Sprayed on inner seals, idle increased. No effect on left outer seal. Got one right.
If I push on either end of the throttle shaft, idle increases.
I know Mailman is having trouble with his butterflies hanging open, not a problem with mine, operating smoothly. (So I thought) But I just read in Mailmans new “Carburetors hanging open” thread that Time machine and 5twins think it might be that his carbs aren't quite mounted properly in the brackets, thus causing his binding.
They, Scott and 2M suggest to install all springs and linkage before snapping butterflies closed and 2M recommends then applying some pressure to the staked throttle shaft washer while tightening throttle shaft butterfly screws. I didn't do that, tightened screws with butterflies positioned without springs etc. I also just noticed that my left side throttle shaft nut had come loose. If I tighten the nut right down, butterflies bind, so maybe there is air leaking in the seals due to the nylon throttle shaft washers not being fully seated? (Although you would think the vacuum would pull them in. Maybe not if the washers aren't fully seated)
I think I may have been my own worst enemy here by not reassembling properly thus causing 2 problems, air leak, and butterfly binding if I try to tighten enough to solve air leak.
So…... got another ½ hour ride in this month. (At this rate I'm way overpaying for insurance, but, not spending a lot on gas)
Coming off again, but don't know when I'll find the time. Hopefully properly centering butterflies with all springs and linkage installed and a little push will solve the problem. Blue LOCTITE says 'REMOVABLE’, sure hope so.
Fingers crossed, I'm spending money on carbs like a drunken sailor and sure am chasing my tail on this.
Boy, Bob, I sure wish now your thread had come a few days earlier…...lol.
Any suggestions or recommendations gratefully received.