82 KZ550 LTD: loss of power and then unable to restart

I was in the midst of a beautiful ride through the fall foliage this weekend on my 82 kz550 ltd and suddenly the exhaust became throaty and when I gave it more gas it didn't respond and became even more throaty. I continued to ride for 30 seconds at lower RPMs but then pulled over and stopped the bike. Then I couldn't start it. Have new plugs and air filter and have checked the hoses. I did use Sea Foam 3 weeks ago. What I plan to do next is to check the petcock and turn it to PRI to see if there might be a clog there or if my problem is with that and from there I'll clean out all of the carbs. Question 1: Should I drain the carbs first and if so, how? Question 2: Previous owner put Harley pipes on the bike--same headers and crossover though--does this require rejetting and if so, any tips?. Question 3Any other idea about what this could be? SHe was running great before.

Many thanks,
Kai



Post edited by: thinkaican, at: 2006/10/11 10:39

del

How long have the mufflers been on the bike? What do your plugs look like? It could be a fuel delivery problem.

By the way, those Harley pipes look right at home on your bike very nice. Do they sound good? I bet they are a bit louder than stock..maybe I'll do it to my bike someday.

Something similar happened to me on my 83 Kz550 but for a known reason. My bike needs to be choked for a few minutes before running smoothly and I headed out of the driveway at full throttle intro traffic without turning off the choke. As soon as I hit 3500rpm my engine went "Blattttt" and I lost all power. I coasted into a driveway, waited a few minutes, and started the bike again without any choke and let some fuel burn its way out. That may not be your problem but I thought I'd toss it out there......

That's a nice bike though. Mine is almost identical, except for black exhaust and ghost flames on the tank. It's a little grumpier than expected but I'm everyone's 23 year old air cooled bike engine is the same way.

I'm not sure how long the pipes have been on there(est. 5 years) and truthfully I don't like them. Whoever installed them was certainly going for noise and that's never been my bag. I'm still trying to get it to the nice hum of my old 750. That's the sound I like. But all in all they do look ok and fit ok.

thanks--so when you installed the 4-1 you must have rejetted. Do they come with instructions on how to do that? The problem you described is one I have had before but I had been riding on this particular day for 10-15 minutes when this happened so I didn't think it was that but I could be wrong. They sure can be finnicky in that start-up stage but once they are warm...what a treat.

I bought the bike last summer with the pipes already installed. If rejetting is necessary then I hope the previous owner took care of it! The carbs had been recently rebuilt and they seem to run pretty well (might need some synchro over the winter). I've never ridden another kz550 but besides startup and cold running it isn't bogging down or losing power under throttle. Never had a hitch once she's warmed up, and not one stutter on my first 200 mile cruise.

The exhaust is pretty tame. I don't care for chrome and big noise unless the engine really warrants it, and my 50 horses aren't going to impress anyone no matter the sound. Good first bike

Hi there,

So I replaced the battery last weekend and drained the carbs and she started right up. I'm not entirely convinced that either one solved the problem. I have taken the carbs out and they look clean. Some of the seals are gone so I will probably buy the rebuild kits and go from there.

Thanks for the help.

Kai

Hi there,

So I replaced the battery last weekend and drained the carbs and she started right up. I'm not entirely convinced that either one solved the problem. I have taken the carbs out and they look clean. Some of the seals are gone so I will probably buy the rebuild kits and go from there.

Thanks for the help.

Kai