KFunk Posted February 20, 2009 Author Share Posted February 20, 2009 thats how you change the float height!! keep moving them and they will snap off eventually!! Crap, I just realized that. I was thinking the other tang off to the side did that. doh. Link to comment Share on other sites More sharing options...
KFunk Posted February 20, 2009 Author Share Posted February 20, 2009 OK, fixed the floats like that, and figured out how to connect the clear tube. Stupidly forgot about the nipple at the bottom of the bowl that is controlled by the phillips screw. But yeah, no real change in running ability of the bike. Seems like the fuel level is pretty good in the tube, almost fills the entire bowl. If I rev the bike a bit it'll take the fuel level down to almost the bottom, it supposed to do that? Anyways problem isnt revving it, its trying to get it to idle. I tried switching to the hotter plugs, and it might run a little easier, but not by much. Either way, the right cylinder always seems to run way way leaner than the left cylinder, maybe the things are way out of sync? I tried to crank up the idle speed with the big knob, but then I noticed it was already cranked in almost all the way.... hmmm, that it explains why it idled really high after getting warmed up before on the few times I had it out riding. I bet the P.O. cranked it that high just to keep it running.... and explains why he got frustrated with it and sold it to me for $150... Oh well, I'll get 'er goin again sometime. I'm thinkin I might have to just wait till a warmer day to get it somewhat running to tune it. It's about 20F here today. I'm in a somewhat warmer attached garage, but I gotta leave the door open when I run it. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 20, 2009 Moderator Share Posted February 20, 2009 sounds like you have a fuel supply problem. is the tap really clear of crud? is there a sucking sound when you open the petrol tap? (breather blocked) could try to rig a temp fuel supply and see if it runs ok. (to eliminate the above problems) Link to comment Share on other sites More sharing options...
gabby Posted February 21, 2009 Share Posted February 21, 2009 put the fuel pipe from the tank into a can and turn it to prime to see if you have a steady stream, it seems to me if your float bowls are nearly emptying from just revving it a bit then the fuel cant be flowing freely enough from the tank. Link to comment Share on other sites More sharing options...
KFunk Posted February 21, 2009 Author Share Posted February 21, 2009 Almost there! I can get it to start with the kick starter alone pretty easy and run for a while, but still doesn't seem to want to idle. I went ahead and took the petcock out and everything looks clean as can be. The fuel level seems to be OK now, but the bike runs way better when its on prime and the fuel level is a little higher. I think I'll try a new hose and clamps on the vacuum line maybe. I took the synch screw out a good bit, too, and that might help. Still seems odd though that right cylinder looks really white/gray no matter how much i richen it, and the left cylinder always looks black no matter how lean I go. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 22, 2009 Moderator Share Posted February 22, 2009 I took the synch screw out a good bit, too, and that might help. Still seems odd though that right cylinder looks really white/gray no matter how much i richen it, and the left cylinder always looks black no matter how lean I go. yep its the same with mine, they (yamaha) did sometimes have different jets for each carb, so check you havn't inadvertantly swopped them over if you have those jets. did you take the pet tap completly off as i suspect the diapram is not as efficient in releasing fuel. you can get kits form HVG cycle and mikes xs Link to comment Share on other sites More sharing options...
KFunk Posted February 23, 2009 Author Share Posted February 23, 2009 i think the idle circuit just isn't working. I can get it to stay at a relatively constant 1 to 2K, but only if I apply a little throttle. Cranking in the idle speed screw all the way doesn't help. I think it has to do with that pilot jet I mentioned earlier, and the tip being clogged. The clogged one corresponds to the cylinder that runs lean...Soaking in brake cleaner and blowing with air pump still didnt unclog it. I made another attempt to unclog it, which helped the situation, but didn't solve it. Now I'm gonna try soaking in PB Blaster a while. I don't have a good air gun handy and had been using a 12V tire pump. I'm gonna have to venture somewhere to use a real compressor, maybe. Or maybe I can just use some air from one of my car tires somehow to get a sudden blast.... and yeah, I took the petcock all the way off and went thru it. The diaphragm seems ok in it. Link to comment Share on other sites More sharing options...
KFunk Posted February 23, 2009 Author Share Posted February 23, 2009 There, its purring like a walrus now. It was those pilot jets. Thought I had them cleaned out, but I guess not. I ended up using the bristles on a toothbrush. Figure they can't damage like a wire can. Now I can see light thru them pretty easy. I can't really go for a test ride right now, its 25 degrees and theres snow on the ground. I'm not sure if its revving as smooth as it should yet, though. Seems to want to stumble a bit, then gets stuck at high revs after you let off the throttle. Should probably get building myself a synchrometer... Link to comment Share on other sites More sharing options...
KFunk Posted February 25, 2009 Author Share Posted February 25, 2009 hmmm, actually had essentially no spark on the left cylinder! That would explain why the spark plug always looked black there. Exhaust pipe was cold to the touch after some running... engine would die completely after pulling right plug wire, but no change if I pull left wire. It'll arc to the block just fine though, and shock the crap out of me. Tried a couple different plugs, no change. Tried closing the gap some, and then it'd fire and pop at random bad times. Opened the gap up a lot wider, and it seems to run better, and the exhaust pipe will get hot. Also used my hotter plugs I got sittin around. I'm wondering if the coil is just weak. I gotta pick up a decent multimeter and check the resistance on it. At least used coils look cheap on ebay. I'm wondering if it could also be caused by PO's crappy wiring mishaps. Some of the fuses were wrapped in tinfoil.... and they got really hot to the touch before. Wondering if that let too much juice thru and got the coil hot as well (i know my car's coil doesn't like working when its hot). So yeah, I just pitched all of that tinfoil. Ignition didnt want to come on at all at first after removing it, but I wiggled things around and then the lights came on. Supposed to be a warm day tomorrow, might be time for a long ride finally! Oh and I've got my homemade synchrometer all ready to go, and might try it out tomorrow. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 25, 2009 Moderator Share Posted February 25, 2009 coil will only get hot if theres a fault or it can't fire the plug. Could be a faulty ht lead!! problem is the're bonded in, but you can dremel the side and pull the ht lead out and epoxy a new one in try swapping coils to check drewps Link to comment Share on other sites More sharing options...
Cy Welch Posted March 2, 2009 Share Posted March 2, 2009 Thanks again for all the help, you're providing way more info than the manual. It'd take me forever to figure it out without you. I just checked the valve clearances for the heck of it, and all seem ok with no adjustments necessary. Not as easy to check as my old BMW car, but do-able. Next I want to check out the breakers to see 'em, but I can't figure out how to get out the little plug that goes over one of the phillips head screws that holds the breaker cover in. Looks like I'm gonna have to get a drill, but is there something I'm missing? Sorry for all the newbie-ness, but I can't seem to find much of the info I want thru the search. You don't have breaker points, you have electronic ignition. Unless you take it apart that part of the engine is never supposed to be opened up. Check your timing and if it's right don't worry about it. Link to comment Share on other sites More sharing options...
KFunk Posted March 2, 2009 Author Share Posted March 2, 2009 Well, I spent a couple days last week riding all around town and out some country roads. :D I had a great time and it felt pretty damn strong, but I don't have much experience with bikes larger than 50cc. I went ahead and synched the carbs using the yard stick/tube/ATF method, and it seemed to run pretty darn smooth after that. But for some reason its a real pain to start if it sits overnight, and then it'll only idle on the right cylinder. Even when revving it in neutral, the left cylinder's exhaust pipe never gets hot. Once the thing gets warmed up after a bit of riding, the left cylinder seems to start doing better, and the idle gets faster and faster and I have to crank down the thumbscrew to keep it from idling too high. I went ahead and swapped the coils between the two sides, and there was no change. Still the left cylinder does nothing at cold idle. I've gotta go ahead with a proper compression test, next? I tried it real quick and got like 100-150 psi out of the left one at first, but then it went to nothing for some odd reason. This is while it was idling on the right cylinder... i know thats not how you're supposed to do it though, and am looking for the proper procedures. With cars, you've got to run it for a while and get it fully warmed up, then pull all plugs and turn it over a few times till you get the highest reading. Same for this bike? In any case... just wondering if the compression rings on the left side are pushing out as much as they should... Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 2, 2009 Moderator Share Posted March 2, 2009 I've gotta go ahead with a proper compression test, next? I tried it real quick and got like 100-150 psi out of the left one at first, but then it went to nothing for some odd reason. This is while it was idling on the right cylinder... i know thats not how you're supposed to do it though, and am looking for the proper procedures. With cars, you've got to run it for a while and get it fully warmed up, then pull all plugs and turn it over a few times till you get the highest reading. Same for this bike? In any case... just wondering if the compression rings on the left side are pushing out as much as they should... checked your valves recently? the PSI checking is the same for cars. to confirm compression try a bit of oil in the cyl and see if there is a difference! Link to comment Share on other sites More sharing options...
KFunk Posted March 3, 2009 Author Share Posted March 3, 2009 checked your valves recently? the PSI checking is the same for cars. to confirm compression try a bit of oil in the cyl and see if there is a difference! Yeah, I checked the rocker clearances not too long ago, and that seemed fine. It appeared they were opening and closing just fine, but I didn't investigate extremely well. Perhaps worth another look. Yeah... I figure if its warmed up really well I'm sure to get good comp, but should prolly double-check. Just too cold to take it out right now to warm it up right. At least it can't be too hard at all to change the rings on this thing. Before I go that far though, I'll try to run the crap out of it to see if I can get 'em loosened up. After all, this thing is 27 years old, and quite possibly has only 2000 miles on it... perhaps the lil expander that goes under the ring isn't expanding as quickly as it should (if it even has that, like my RX50 has). Link to comment Share on other sites More sharing options...
KFunk Posted March 6, 2009 Author Share Posted March 6, 2009 Still been starting really hard in the morning. But when it got goin yesterday, the left exhaust pipe warmed right up, so it must be workin now. I think those rings just needed some stretching. So it was warm yesterday and I had my fresh tires on, so I put some miles on it. I went about 50 miles of backroads and had a great time. I think its up to 2075 miles now. : When I had the wheels at the bike shop to get the tires mounted, the shop owner said the sprocket looked brand new and the tires had full tread depth (they were just old and cracked and couldn't hold air). So yep, thats the real mileage. I actually got it up to 70 or so on the 4-lane highway back home. It seemed like I was fighting the wind the whole time, but I'm not used to goin that fast on bikes. My friend on his V-Star 650 said he was fightin the wind too yesterday, so I guess its not just me. Link to comment Share on other sites More sharing options...
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