[BoominSVX]

Well hello, I'm new to this board as an 88 Katana owner. I got this from a friend of my brothers with a problem. It starts right up and runs great....until it gets hot. Once the temp gets good and warm, she begins running like poopy. It dies if you let the throttle go, and it's a PITA to start again until it has a few minutes to cool. I tried to see if the gas tank vent was bad, but even with the cap off, she's dead. The bike runs great if you jump on and go around the block a few times, but after about 6 mins of run-time, I start to get a big headache. Any ideas guys? Let me know if you are sitting at the computer smiling right now cause you know the answer. mmm kaay...lata

 

[Drake]

I'm confused by one thing.....

... but after about 6 mins of run-time, I start to get a big headache....

Are you getting a headache from high rev madness, or from fumes? The headache thing just threw me. This sounds like all carbs. If you are having to ride on the throttle so much to keep it going, then you have too rich a fuel mixture. Check your carbs(floats, diaphragm, slides, jets etc.), clean em up get everything back on and then start her up. Adjust your air screws on the carbs by ear (open them up slowly until you get the best idle). Might be worthwhile to check your plugs condition and make sure you are getting good spark.

So, let me reverse the order here..... Check your plugs. Make sure you have good spark to each of them (don't worry about timing for now). Then try just adjusting the air screws on your carbs. Then, if that still doesn't fix it, pull the carbs, clean em up and check for parts that might need replacing (listed above)....

Good Luck

 

[The Chad]

did the guy that sold the bike to you by chance adjust the valves rescently, as in just before he sold it to you?

 

[DrBob]

Sounds like vapor lock. Check the routing of the fuel lines- if they are not in the factory location, they could pass too close to a heat source, which boils the fuel in the line and causes the problems you describe. Once the thing cools a bit the fuel turns back into liquid and it will run again.

 

[BoominSVX]

Allow me to clarify on this. The headache is that the bike won't idle or start if it dies. This is why I get annoyed, scream at the guages to hurt the bikes feelings, and get all flustered. I am going to check the vapor lock thing now. Just out of curiousity, do you think it could be a coil issue? They seem to shoot a nice pink spark even hot (the outside ones at least). Thanks for the help guys. Mikey

 

[The Chad]

pink spark is weak, you want blue, it is harder for a spark to occuer when in the cylinder, due to the compression, you want/need a nice blue spark

 

[BoominSVX]

Trust me, this spark was strong and wide. I may have been at a bad angle. Just an update though. I went through the bike again today, took all the plastics off, the air box, and a few other things. I started it up and shot carb and choke cleaner into the carbs 1 at a time with the bike running and playing with the throttle (obviously). Half a can later, I started checking revs and looking for issues. I was sure I had the problem cured. Idle was great, response was snappy, so I threw the plastics and air box back on. Now the thing is reving at 3,000rpm again. Has anyone ever heard of an air filter being so clogged that it would make the bike rev that high? Choke is off, gas is on ON with 1/4 tank. I'm going to pull the filter out again tomorrow and see if it comes back down. I'll let you know. Lata