The bike has 6700 miles on it. I know it's due for valve adjustment, but I don't believe thats it. At 4700 miles it had this noise also. It's only under a load. When in neutral no noise, when in gear and not moving no noise, but when you start off and give a little throttle, noise. When cruising thru town any gear and roll on throttle the rattle (noise) is there under 4 grand. The noise seems to disappear after 4 grand but that might be because of wind noise and exhaust noise. Has anyone else experienced this??

 

What is your maintenance schedule like? and how did the plugs and piston tops look?

 

I purchased the bike with 4700 miles. I cleaned the airfilter and changed oil as soon as I got it. The bike was dropping #1 cylinder at idle when we 1st got it. I cked the carbs made sure jets were all open and flowing. Still dropped #1. I drilled out factory seal and found that fuel mixture screws were all over the board, with #1 at 1/4 turnout, #2 at 3/4 out, #3 was 1 1/4 out, and #4 at 1 3/4 out. I set them all at 2 1/4 out and that solved that problem. It starts without the choke and is much stronger off idle to 4000 rpm. The plugs that were in it when I got it seemed a little lean. Not much color. I know these bikes are set at factory very lean, so not much concern there. It's due for a valve ck but I would think if valve was loose it would be noisey from the get go. I was also wondering about the cam chain, though the manual does'nt say anthing about camchain adjustment.

 

Dropping #1 cylinder? So have you synched the carbs yet?

Really on the cam chain adjustment. The adjustment is kinda a deal also. since the automatic adjusters are hit and miss with the kawis

 

sounds like valves or the cam tensioner

 

Yes the carbs are synched. Since weather is now turning I'll tear into it and ck valves and cam chain tensioner. I was going to install a factorypro jet kit anyway since I put a hindle can and midpipe on. Thanks for the feedback.

 

I think I may have found the source of the noise. I was cking valve clearance today. The bike has 7100 miles on it. The shop manual says valve ck at 7500 miles. All valves were tight. But #1 exhaust and #3 intake valves had no measureable clearance. I figure that #3 intake valves must be staying open slightly during combustion cycle and blowing back threw carb. I'm going to let the local kawasaki shop set the valves since there's no way to calculate shims for #1 ex and #3 in, I figured it would cost me more in time and gas to get the shims(multiple trips) than just letting them do it. I'm trailering it to them and they quoted me 2-2 1/2 hrs labor since "they don't have to tear it down," At least when I get it back I can double ck their work.

 

Right on 3cylinder

 

My 750 has the same problem. It's a cam chain thing if you have low RPM rattling that goes away when you rev it higher. You better get the tensioner checked since the bike's apart anyway.

Dragone#19 is right about Kaw's being hit and miss on tensioners. Several people have said the same thing about them.

 

Well my guy at the Kaw shop finely came off vacation and the bike is there. I asked him to document what # shims come out and what are going back in. The cam chain adjuster will be removed and reset during the valve adjustment process. I installed a Factory Pro jet kit. I can't wait to get it back and fire it up. The stock MJ's were 160's and 165's. PJ's were 38's.
I replaced the MJ's with 175 and 178's and the PJ with 40's. Also drilled out Main air jets to 1.1mm and 1.2mm. set the needles at 2nd notch from top. Also set the fuel mixture screws at 1and a half turns out. I'm sure there be a little tuning involved but at least she'll be able to breathe.