kvanderploeg
The Dutch Terror
Glad to hear it, Emz! 
Kent
Kent
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post carb cleaning, trouble
- Thread starter emzdogz
- Start date
-
- Tags
- carbs enrichener firing
well, I can't claim life isn't interesting.
Now the same prob as before, is happening on the OTHER (L) side. Running rich, but backfire, hiccuping through exhaust pipe. One thing is the L carb would overflow when filling from empty bowls, but I put a 2nd new float needle in, and this one seals nicely even when filling from empty. So I know it's not overflowing.
Floats are set exactly evenly at 27.3-5 mm.
I bought a tool, so I can now really tell the float height.
When I first put this set of carbs on I was so thrilled that the right side was now running and heating up, that I failed to notice that the L side was now doing the thing that the R side used to do with the other set of carbs on. And just like it used to be with the other set on R side, manipulating mixture screw while running has little effect, and removing vacuum cap from intake boot also has no effect on the bad/slow/backfiring side. It's not as severe as the problem was before, with my old carbs on the R side. At least this now-bad-running L side does heat up some and respond a little bit to changes to mixture screw.
I guess I know now it's not rings or valve related though. I think I now know that the smoke and gas in pipe and bad running are from carb.
Thinking of taking the 2 pairs of carbs apart and using the good R one from this set I have on now, and the L from my old set.
Was chatting with my neighbor yesterday who used to have some kind of 4 cyl UJM and he said it had a prob with one carb. He did all kinds of things to try and fix it (things that sounded really familiar) and he ended up having to take it to a shop. They told him that one carb was "cracked" - and he had to replace that entire carb: one of the 4.
Have gone through pilot and air circuits again.
Also on L side I'm getting this mysterious little drop on oil on the cooling fin surface right under the sparkplug. Can't tell at all where that's coming from.
Now the same prob as before, is happening on the OTHER (L) side. Running rich, but backfire, hiccuping through exhaust pipe. One thing is the L carb would overflow when filling from empty bowls, but I put a 2nd new float needle in, and this one seals nicely even when filling from empty. So I know it's not overflowing.
Floats are set exactly evenly at 27.3-5 mm.
I bought a tool, so I can now really tell the float height.
When I first put this set of carbs on I was so thrilled that the right side was now running and heating up, that I failed to notice that the L side was now doing the thing that the R side used to do with the other set of carbs on. And just like it used to be with the other set on R side, manipulating mixture screw while running has little effect, and removing vacuum cap from intake boot also has no effect on the bad/slow/backfiring side. It's not as severe as the problem was before, with my old carbs on the R side. At least this now-bad-running L side does heat up some and respond a little bit to changes to mixture screw.
I guess I know now it's not rings or valve related though. I think I now know that the smoke and gas in pipe and bad running are from carb.
Thinking of taking the 2 pairs of carbs apart and using the good R one from this set I have on now, and the L from my old set.
Was chatting with my neighbor yesterday who used to have some kind of 4 cyl UJM and he said it had a prob with one carb. He did all kinds of things to try and fix it (things that sounded really familiar) and he ended up having to take it to a shop. They told him that one carb was "cracked" - and he had to replace that entire carb: one of the 4.
Have gone through pilot and air circuits again.
Also on L side I'm getting this mysterious little drop on oil on the cooling fin surface right under the sparkplug. Can't tell at all where that's coming from.
Last edited:
kvanderploeg
The Dutch Terror
I will say that I spent way more time on that right side carb trying to clean the pilot circuit than I did on the left. You might try that bread tie wire trick on the left one as well, just to be sure. Seal the mixture screw hole with your middle finger, the mixture screw outlet in the carb throat (I used a piece of Scotch tape), seal the main jet hole with your thumb, shoot a liberal amount of carb cleaner into the pilot hole (with pilot jet removed) and shoot compressed air into the pilot hole. You'll be wishing you had more hands. 
Kent
Kent
kvanderploeg
The Dutch Terror
You bet. Keep up the good work and keep us posted.
Kent
Kent
oldskoolcarbs
XS650 Addict
http://s591.photobucket.com/albums/ss351/wildmanv65/AAAA11%20OLDSKOOLCARBS/EM%20XS6500/ what i found, the main set was way out of sync(butterflies) one mixture screw was at four turns out, the other at 3/4 turns out, one choke plunger not sealing, one diaphragm had a hole in it and one of the float valves had burs in it causing the needle to hang sometime...
Just for the record, (saving some face here) I wasn't trying to run it (and didn't ride it at all) with mix screws in those positions the whole time (that's just where they happened to end up on the day I finally said forget this sh_t) - and as for the sync, I'd been fiddling with it while running, so I'm not surprised to hear that was out of whack. Glad to hear that "concrete" issues were discovered though.
The diaphragm with a hole in it was in the 2nd pair though, right? not in the main pair?
Glad to hear about the choke plunger too. That makes sense - so that would allow extra gas to continue to enter that carb, correct - even with choke knob pushed all the way in?
I bet that was the main problem right there. I didn't take the choke assembly apart at all.
OK, can't wait to get these back on the bike! From the pics, they look really nice now. Guess I'm gonna have to actually clean the engine up now, to match...
Thanks, Rick.
Em
The diaphragm with a hole in it was in the 2nd pair though, right? not in the main pair?
Glad to hear about the choke plunger too. That makes sense - so that would allow extra gas to continue to enter that carb, correct - even with choke knob pushed all the way in?
I bet that was the main problem right there. I didn't take the choke assembly apart at all.
OK, can't wait to get these back on the bike! From the pics, they look really nice now. Guess I'm gonna have to actually clean the engine up now, to match...
Thanks, Rick.
Em
This is a great exchange. Thanks for the threads EMZDOGZ, it may be a little tough to air in public but a thread like this should probably happen more often. Carb overhaul /troubleshooting repair is not trivial. Maybe I am denser than most but after at least 15 or 20 sets of carb overhauls I am still learning, picking up tips and occasionally getting stumped. I am always jealous when I see oldskoolcarbs work. It forces me to raise my bar!
I used to love working on carbs and would never consider letting others work on my carbs. But that was when I could see what I was doing... I'm thinking I might send a set to oldskoolcarbs.
Even though I guess you could say I 'failed", since I did send the carbs off to Rick and was not able to get them working properly myself, I don't really have any regrets over trying to get them working. I learned a lot. I have a much better understanding now of the workings of the CV carb. And yeah I agree that carb work is neither trivial nor a "gimme". I guess I shouldn't say anything until I get these on the bike and hear it running right, but I know from another XS650 I used to own how huge of a difference a healthy set of carbs can make.
re: the "seeing" thing...yeah, I have to say that's getting to be an issue for me, too. Also not having a proper clean place to work on them.
So it's great to have the option of sending them to a pro like Rick.
re: the "seeing" thing...yeah, I have to say that's getting to be an issue for me, too. Also not having a proper clean place to work on them.
So it's great to have the option of sending them to a pro like Rick.
oldskoolcarbs
XS650 Addict
EM, YOU CAN REBUILD CARBS NOW, you have enough practice... for the record Every circuit and jets on the carbs were perfectly clear and clean when i got them, good work,,, you did a great job, just stating what i found.... i believe the choke plunger was the biggest culprit , the rubber was deformed, even pushed all the way in it was not sealing.. like i said in the email, the Canadian needles are in the set i sent and i hope the 135 mains are the matching jets for the the needles.. i read on here where a few people said you have to use the jets that come with the needles... only one-way to find out is to ride it,,, thanks again,,, rick
So, I do believe this thread can be DONE now! 
Today I went ahead and installed the shiny newly refurb'ed carbs.
YAY!!!!!!! runs perfectly I do believe. No smell of gas, no leaks, no one cylinder running hotter than the other, etc. No backfiring or popping. No hanging when I let off. Throttle response is crisp crisp crisp!!!!! Better than my fuel injected '07 Sportster. Whack the throttle open and it screams instantaneously - not a second later or "pretty quick" but immediate. NICE!!!!!!!
I didn't take it out on the road, as I have a bunch of stuff to still deal with - but I do believe my carbs issue, since I got them back from OldSkoolcarbs (Rick) is OVER!!!!
The only think that puzzled me a bit is that it didn't seem to want to start from cold with choke on. It is very warm here though - it started right up with no choke, just feeding it some throttle. So, I dunno, since it did start up easy once I pushed the choke in, I'm not gonna worry about it.
Still lots to do on this bike - but I just wanted to post one more time in this thread and say that correctly set and healthy carbs are like GOLD. And again, that OldSkoolcarbs's services are excellent, and I definitely recommend it.
thanks to everyone who posted in this thread.
Aunty Em
Today I went ahead and installed the shiny newly refurb'ed carbs.
YAY!!!!!!! runs perfectly I do believe. No smell of gas, no leaks, no one cylinder running hotter than the other, etc. No backfiring or popping. No hanging when I let off. Throttle response is crisp crisp crisp!!!!! Better than my fuel injected '07 Sportster. Whack the throttle open and it screams instantaneously - not a second later or "pretty quick" but immediate. NICE!!!!!!!
I didn't take it out on the road, as I have a bunch of stuff to still deal with - but I do believe my carbs issue, since I got them back from OldSkoolcarbs (Rick) is OVER!!!!
The only think that puzzled me a bit is that it didn't seem to want to start from cold with choke on. It is very warm here though - it started right up with no choke, just feeding it some throttle. So, I dunno, since it did start up easy once I pushed the choke in, I'm not gonna worry about it.
Still lots to do on this bike - but I just wanted to post one more time in this thread and say that correctly set and healthy carbs are like GOLD. And again, that OldSkoolcarbs's services are excellent, and I definitely recommend it.
thanks to everyone who posted in this thread.
Aunty Em
TurboFarviknugn
XS650 Addict
Wow, this is the end of a great thread. You are a better man than I, cause i woulda sent them suckers off after about 5 hours of dicking with them. This thread so should be a sticky !!!!
Congrats to finally getting some resolve to your issue.
Congrats to finally getting some resolve to your issue.
