Wow what a ride....

So my brother decided he wants a KZ1000 as well to do a "Sanctuary" type build on as I am with my KZ900. So I find an '81 CSR that is on its second owner. Carbs are rebuilt and the bike is a running/driving unit. battery is weak as the owner wore it down trying to start it this winter. Anyway, the only year he really didn't run it is last year (2011). So he added Seafome to the gas and filled it up. It started right up, but didn't want to idle without the choke on. The engine sounded good, so I bought it. Went to pick it up last night, and was riding it home. Wasn't running well, and wouldn't idle. Took it easy and could maintain about 45 mph. It was low on fuel, so I stopped at a gas station, well the bike stopped and I pushed! Filled it up, and it started to run better. So I kept on.

Swapping between 3rd and 4th depending on hills (ugh) and would lean into it until it would start to pop out the exhaust, then back off. Kept doing this and the bike was slowly picking up speed and running better. About 5 miles from home, in a corner, she popped once and this thing like flipped a switch! She ran like a cheetah on cocaine! Smooth and power galore. Ran like this all the way home. She still doesn't like to idle unless you ever so slightly, start to twist the throttle.

So I am assuming the pilots are a little gummed up yet? Should I just try to add some gumout to the tank and run it a little more? Maybe try some carb cleaner down the pilot hole in the bore? Also my wife was following and she said that just before the "light switch flipped" the right outer exhaust pipe was glowing a little near the head, but went out as she thought I was going easy on it. It turns out that is when it decided to run fantastic. It never did that glowing again. Do you think it damaged anything? It certainly runs good now, except at idle.

Comments, questions, consolations?

Cory (safe at home...)

you might try another can of seafoam in the tank and run it through.

it does sound like you had a partially clogged jet that was causing you to run lean which is why the exhaust was glowing,and still prolly have a little blockage which is the idle problem.

thats my .02 ymmv,

leon

Yeah, I should also point out it was at 9:30 at night which would have made it more visible. I may try a few things that are more non-ivasive over the next couple days.

Cory

Try the seafoam and run a few tanks or you could open the bowls and manually clean the jets. Cleaning the tank might be in order too.

Looking down in the tank, it is beautiful. Clean and rust free. The gas that was in it, didn't have the smell we all dread at all. He didn't add enough Seafoam, per the instructions, so I'll add more. I think it is really close to running well throughout the range. Would hat to tear them apart for one little spec of crap....

Cory

Could try running with fuel cap ajar to simulate proper tank venting.

Would also assure timing advancer is properly functioning (i.e., isn't sticking or handing), as it may require lubrication or both cleaning and lube. Suddenly moving past the snag might be what flipped the switch.

Good Fortune!

That is a good point. I'll pull the ignition cover and see if it appears to be free moving. I can 'lube it when I am in there.

Cory

Pulled the ignition cover, and looked at the advancement plate(s). they looked good and worked smoothly (now?), so if it was stuck, it isn't anymore. Oiled the joints with some WD40 and closed here back up. After running it today (I put Techron in the tank) and it really does well 2K and above, maybe even 1500 rpm and above. I am starting to think the problem is the carb manifolds/boots/holders. They are original, and have had the carbs taken in and out a few times. I think they are causing a vacuum leak, causing the idle to suffer. Explains the current symptoms. My brother ordered up replacments, and in the meantime, will probable bump up the idle adjustment and just let her idle higher until the new manifolds get here from Z1. Will let you know how it goes.

Cory

Spray some carb. cleaner or starting fluid on the carb. boots while the engine is running. If there is a vacuum leak the rpms should surge for a bit.

Well, I will do that later, however the boots/manifold are not the issue. Pushed around on them and they are nice soft and pliable. Must have been changed when the carbs were rebuilt. the airbox to carb boots, are rock hard and not seated/sealed to the carb inlets. Could this be causing the idle issue? How sensitive would these carbs be to that?

Cory

NakedFun wrote: ...Oiled the joints with some WD40....

A drop of motor oil would be better to lube the advancer pivots.



Glad to hear the advancer doesn't look like this:




Good Fortune!

It was smooth and issue free. The WD40 was for staving off surface rust and to make me think I was actually doing something.... :whistle: Anyway after another fill up and making it from work, the bike actually tried to idle for a while on its own! Not really smooth but around 900 rpm. How many turns out should the idle knob in the center of the Carb group? I think it is about 5 to 6 turns out.... I turned it out another 3/4 of a turn and that seemed to help... Thoughts?

Cory