GaSo Posted March 28, 2009 Posted March 28, 2009 set mine at 26mm and it was too rich. so i got them at 28mm. Haynes wanted then at 32mm which was way too lean yea I only have about 10 miles on the 26mm setting, I suspect 26mm may be a tad too rich for me as well.
ajc99z Posted March 29, 2009 Author Posted March 29, 2009 Finally got the carb put together and back on the bike with some new (to me) carb holders. Still runs on 1 cylinder and must be on full choke to idle. However, it revs and revs well settling down around 1500 rpms. I switched the coils to see if a bad coil was the reason only 1 cylinder worked. Same cylinder fires everytime regardless. Spark plugs are new. In order to get it to run / rev for any substantial amount of time i have to switch the petcock to "prime" then over to run and i'm good for a couple of minutes. Although, on one instance I took it for a quick ride without any choke and it did well, just had to keep reving it. But to get it to start and stay started it needs full choke most of the time. Some other thoughts: The float heights were in the 26-27mm range, unfortunately not the most exact process. I adjusted the air/fuel mixture from 3-5 turns from seated and couldn't tell much difference. The springs, washer, and o-ring are new. I noticed when i was putting the tank/petcock back on the bike the petcock would drip in either the "RES" or ""RUN" settings and of course a full stream on the "prime" setting. If I remember, the res and run settings should completely seal the fuel from leaving the tank. Right? Sprayed carb cleaner around the intake boots and carb holders when running and noticed no difference in revs. I should also mention that yesterday the battery was completely dead. It charged at Autozone overnight and the starter worked well upon reinstalling. After quite a bit of starts today i was back to kick starting as there didn't seem to be enough juice to work the starter. Looks like i'll need a trickle charger until i can trace that issue. I'm fairly happy that i was able to take it for some quick rides around the neighborhood. Felt pretty fun albeit on 1 cylinder. But would still like to work out the kinks. Everyone's help is appreciated.
Moderator drewpy Posted March 30, 2009 Moderator Posted March 30, 2009 Finally got the carb put together and back on the bike with some new (to me) carb holders. Still runs on 1 cylinder and must be on full choke to idle. However, it revs and revs well settling down around 1500 rpms. I switched the coils to see if a bad coil was the reason only 1 cylinder worked. Same cylinder fires everytime regardless. Spark plugs are new. In order to get it to run / rev for any substantial amount of time i have to switch the petcock to "prime" then over to run and i'm good for a couple of minutes. Although, on one instance I took it for a quick ride without any choke and it did well, just had to keep reving it. But to get it to start and stay started it needs full choke most of the time. are you getting sparks? is there compression? did you check the floats where they just cut off fuel from the bottom of the carb gasket face to the upper most float? have you timed the ignition with a strobe? I still think there is a blockage in the carb if adding choke (ie more fuel) helps!! The float heights were in the 26-27mm range, unfortunately not the most exact process. yam service manual states 26mm plus or minus 2.5 mm, fair bit to play with I adjusted the air/fuel mixture from 3-5 turns from seated and couldn't tell much difference. The springs, washer, and o-ring are new. mmm!! should be able to tell the difference. could be related to an air leak you have somewhere or pilot system blocked!! I noticed when i was putting the tank/petcock back on the bike the petcock would drip in either the "RES" or ""RUN" settings and of course a full stream on the "prime" setting. If I remember, the res and run settings should completely seal the fuel from leaving the tank. Right? no fuel should leak in res or run, so a repair kit is in order and check your vacuum line for leaks as well Sprayed carb cleaner around the intake boots and carb holders when running and noticed no difference in revs. I should also mention that yesterday the battery was completely dead. It charged at Autozone overnight and the starter worked well upon reinstalling. After quite a bit of starts today i was back to kick starting as there didn't seem to be enough juice to work the starter. Looks like i'll need a trickle charger until i can trace that issue. I'm fairly happy that i was able to take it for some quick rides around the neighborhood. Felt pretty fun albeit on 1 cylinder. But would still like to work out the kinks. Everyone's help is appreciated. check the voltage with a charged battery @ 3k revs, should be about 14.5 to 15 volts, suspect voltage regulator if not Drewps
ajc99z Posted March 30, 2009 Author Posted March 30, 2009 are you getting sparks? is there compression? did you check the floats where they just cut off fuel from the bottom of the carb gasket face to the upper most float? have you timed the ignition with a strobe? I still think there is a blockage in the carb if adding choke (ie more fuel) helps!! yam service manual states 26mm plus or minus 2.5 mm, fair bit to play with mmm!! should be able to tell the difference. could be related to an air leak you have somewhere or pilot system blocked!! no fuel should leak in res or run, so a repair kit is in order and check your vacuum line for leaks as well check the voltage with a charged battery @ 3k revs, should be about 14.5 to 15 volts, suspect voltage regulator if not Drewps I don't think i am getting any spark on the left cylinder. Plug looks as new as when it came out of the package. Prior to purchase we ran a compression test and it was between 140-170 psi and within 15 psi of one another. Don't remember the exact psi, but it was within yamaha spec. I checked the float height from the face where the gasket touches to the upper most part of the float ball. I held each float so the tang was just above, but not touching, the tip. I haven't timed the ignition. Probably wouldn't hurt, will price some lights this evening. Will check for air leaks again this evening. i'll also try turning in (closer to seated) the air/fuel screws to see if it reacts. Could idle screw adjustment being wrong play into the fact it won't idle without choke? I should also note that i didn't disassemble the butterfly assembly when breaking down the carb. Therefore i don't know the condition of the seals within. This may be a source of an air leak? What do you think about the non-vacuum petcock sold on MikesXS? Is this a fair subsititute for a rebuild? Curious if anyone has experience with them? Sure hope the carb is clean but i've read your previous posts in which you recommend the ultrasonic cleaning. Will keep this in the back of my mind as a possibility after i've explored everything else. Thanks.
GaSo Posted March 30, 2009 Posted March 30, 2009 I had a leak just like that, would only idle with the choke on full until FULLY warmed up, and even then gave me issues. Was the seal on the butterfly control rod. Used some of that "3 in 1 oil" that had a nice long flexible pipe to drip oil on each of the surfaces until I found the one that sucked in oil. Of course with how straightforward and cheap the seals are, may just be worth it to replace all. I replaced most of my philips with hex head while I had it apart, also had to replace one of the four screws holding the plates in the butterfly valves as I had it a little worse for wear by the time I got it out If it does appear to be those seals, here is some info: http://www.yamahaclub.com/forums/index.php...ost&p=80253 If there is no air leak, then maybe just keep cranking the pilot screw out on the side that isn't firing? Mine had to come pretty far out to start firing that cylinder, I think around 5 is when it started purring to life.
Moderator drewpy Posted March 30, 2009 Moderator Posted March 30, 2009 I checked the float height from the face where the gasket touches to the upper most part of the float ball. I held each float so the tang was just above, but not touching, the tip. What do you think about the non-vacuum petcock sold on MikesXS? Is this a fair subsititute for a rebuild? Curious if anyone has experience with them? Thanks. the measurement is when you take out the gasket and its from where the gasket sits. The float tang needs to depress the float needle so it just cuts off the the fuel flow (I blow to simulate fuel flow) that is when you check the float height. you can get kits for the petcocks, they come with diapram and special shaped "o" ring and other gaskets to do the job.
ajc99z Posted April 2, 2009 Author Posted April 2, 2009 Finally got it running without any choke for a sustained period of time. I kept her between 3500-4500 rpm for roughly 5 minutes. The goal was to see if i could get the left cylinder (which doesn't like to run) to fire. After a couple minutes, the left exhaust pipe started popping and letting out white smoke. The smoke gradually disappeared as it seemed to have cleaned out some old cylinder deposits. The trick is to now understand why it doesn't fire consistently or right away for that matter. Does this sound like a regulator? Weak coils? The right cylinder spark plug had a greyish/ white tip when i was finished for the night. Running to lean? The air/fuel mix screws are already out 5 turns. Maybe i'll try for one more tomorrow to see if that helps. Regardless, think the carb will be coming off again for another float level measurement.
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