| Author | Message | ||
     Hodakaguy  |
I just installed a mikuni hsr42 carb last night and took the bike for a ride. Other than popping through the carb a little untill it warmed up everything seemed pretty good, then about 15 miles into the ride while going down the highway it started popping, cutting out and backfiring. I limped it a few more miles down the road and it finally just quit. Its getting fuel, it was dripping out the carb. I tried to start it several times and it would try to start and then cut out or backfire and quit. Now thats its home it wont even fire, just turns over. It has spark and its still getting fuel through at least the pumper as I can watch it spray out. Any ideas? Thanks, Hodakaguy | ||
| X1tx  |
If it's dripping out the carb, make sure you don't have a stuck float and the needle valve is seating. | ||
| Hodakaguy |
I think it was dripping from me playing with the throttle trying to keep it running. I just went out in the garage and played with it again, it will turn over without firing but when I pumped the throttle it backfire through the carb and exhaust. I'm not sure if its carburation or ignition. AAARRRGGG. Hodakaguy | ||
| Road_thing  |
If the plugs came out wet after it died, I'd definitely suspect a stuck float. If the plugs came out dry, I'd make sure the needle is secure and all the jets are clear. Either way, you're gonna have to pull the carb apart. rt Edited to add an afterthought: Is there any chance that your tank vent is plugged? Wierd coincidences happen... (Message edited by road_thing on December 22, 2004) | ||
| Firemanjim  |
First check plugs.Did you use choke to start.Probably never have to use it again with Mikuni jetted right.Fouled plug a real possibility.I just hit throttle a couple of short strokes to give a little accelerator pump and off she lights.The popping is a clue.Check for intake leaks,also,and did you plug all those vacuum ports?? | ||
| Hodakaguy |
Well I pulled the carb off and took a look at it. The jets are clear, needle working good and not stuck. So I re-installed the original carb. It still doesn't fire even with the original carb re-installed. While I had the plugs out I took a compression check on each jug and they are both 175psi. Could the timing have moved? Bad intake valve? Thanks, Hodakaguy | ||
| Mikej  |
Use your own best judgement on this, but if it were me I'd squirt a shot of starter fluid into it and see if it fires. Not the best choice but usually a shortcut to a quick answer. | ||
| Hodakaguy |
Found the problem. After switching carbs a couple times with no results I decided to check timing. The timing light would cut out on the rear cylinder when I revved up the engine but would work fine at idle. The front cylinder preformed good throughout the rpm range. I looked at the coil and found the nut had fell off the rear primary wire, the wire was touching the post on the coil just enough to let it run at idle and then cut out as I revved it up. Installed new nuts and washers on the primary connections and it was right back up running. Now just to get the new carb all tuned in and it should be set to go. Thanks for all the help. Hodakaguy. | ||
| Captainkirk  |
I was gonna tell you to check that nut....  | ||
| Firemanjim |
Loose nut always a problem--especially around here!!! |
