kz1000j backfiring through carb

[Mekial82kzp]

thanks, kinda figured that. the highest one is .0055 I think, atleast thats the largest one I could get in there... any advice on my other questions? thanks.

[RichLockyer]

There should be a spec in the service manual, similar to the drive chain, that gives a number of links (pins) and what the maximum acceptable distance from end to end on that is, or the chain is removed and stretched between two sprockets with a specified tension (13kg for the CB750F) and a measurement is taken from two given points on the sprockets (max 177.1mm for the CB750F).
I don't know the specifics for your engine.

Normally, the issue is with the tensioner itself, rather than chain stretch. The plastic parts of the tensioner wear and crack from age and heat, and the tensioner spring loses tension. Chain stretch is typically only an issue on engines that have not been properly maintained... wear on the pins from dirty oil.

[Mekial82kzp]

I measure the cam chain the best I could, max is 5.07" I think but the thing is one part of the manual says "20 links" which makes me think they are talking about the end of a link to the end of the other link at the end of the 20, than there is the specs in the back of the section or somewhere which mentions the pins... the measurement to be taken from center pin to center pin makes more sense to me... in that case I'm within tolerance by a little... can the guides be changed without removing the head? thanks.

[RichLockyer]

On that bike, I don't know.
I know it can't be done on the Yamaha YZ250F, and I don't believe the front tensioner can be changed on the Honda CB750F.
Even if it's possible, the risk is dropping parts down the tunnel into the case.

[Mekial82kzp]

than theres the cam pin count between the cams being off by one... would it even run that way... I've riden it, so I don't know if it some how jumped while I was working with it or if thats how it has been... one pin off, should I remove the cams and re-oriontate? I go in for one thing and I keep finding other things...

[RichLockyer]

Depending on the design of the engine, it MAY run with one of the cams one pin off.
The WR250F compared to the YZ250F has the exhaust cam advanced by 1 pin in order to slightly detune the engine to allow it to work with the more restrictive exhaust.

[Mekial82kzp]

Is the only way to adjust it to the proper pin would be to remove the cam and reposition it?

[RichLockyer]

Yup.

Some aftermarket cams allow for slight adjustments to "degree" the cam in, but most factory cams, it's pin to pin.

[Mekial82kzp]

With it positioned one pin back means either the intake cam starts later than spec or the exhaust cam starts earlier than spec... I wounder if the police model is tuned differantly... although I don't see the benifit of starting the intake late... on a kz1000j with a good timing chain and with the tensioner cap and pin out how does the chain look? how much slack or when lifted right inbetween the gears how far above the gears does it go? thanks.

[Mekial82kzp]

I did a recount and I think it's ok,

to sort of check for overall cam chain and guide ware I used the auto tensioner pin as a guide, it goes all the way in... I checked out my old engine which has had some work done on it and found that it sticks out 5/16" or so and the chain has alot less slack in it, the one on the newer engine in the bike has ALOT of masterlinks on it... the majority of the chain actually...

can I replace the cam chain without a complete teardown? as in get a new chain and masterlink, break the current one, break the new one, temporarily connect them, slacken the joined chains off the crank sprocket, carefuly thread it through, disconnect the old and new chains, and join the new chain with the fore mentioned masterlink.

what do you think?

would this chainbreaker work?
eBay Motors: Motorcycle Cam Drive Chain Breaker Riveter Cutter T34 (item 380098795648 end time Jan-28-09 16:45:16 PST)
z1enterprises sales one but it's $84.37, that seems like alot for one...

[RichLockyer]

I don't think you'll be able to thread the new chain through, and unless you completely remove the cams, you definitely don't want to turn the crank to feed it (which will still need 3 hands... 2 to feed the chain in and out, and one to manually rotate the crank.

That chain breaker is not cheap, but it will safely rivet hollow master links for a 530 drive chain. I bought one for my CB750s.

[Mekial82kzp]

I just want to see if it can rivit my cam chain which is a 82RH2015-152 Link... I just pulled the cams out and I might have to pull the head or more to check my guides... they are grooved but it looks like hey are sapose to be that way although I've been told there not. so they may need to be replaced... man I just took the valve cover off to check the shims... and now I might have to tear down the whole engine...

[RichLockyer]

Give Z1 a call to be sure... they're good people.

[Killbert]

Where is this groove on your guides? On the outside? I wouldn't worry too mouch about your guides unless your valve clearances were off. I say this because my 1100 had 20K miles on it and some out of spec valve clearances, yet the guides were PERFECT upon complete inspection/measurement.

Kellyn

[Mekial82kzp]

There is a groove and it's where the cam would run, it still looks to be in tolerance... I used my caliper which also has a depth gauge built in and compared the exteded depth gauge to the grooves and the grooves look to be less... I changed my shims which 3 valve were less than spec, I removed my cams to do it, the cam bearings/bushings don't look very good, there is ware and some have what looks like streaks and a couple have grooves... Can used bearings/bushings be transplanted? my other engine's cam bearings/bushings look to be in better shape and I was thinking about using them on my current engine, any suggestions... and yes I checked Z1Enterprises and they are currently out. Also kinda off subject, I found a APE cam chain tensioner and I torqued the two tensioner mounting bolts to 7ft/lbs... is that enough? I got the sickening feeling I get when I'm about to snap or strip something when I tried to go any more so I didn't... thanks everyone. As always I'll appreciate any and all info.

[Killbert]

IF you want to swap cam bearings, you will need to measure both your current ones and your new ones. I'm not familiar with the way Kawasaki indexes their bearing sizes but I would imagine they're different in thickness. the best way to do this measurement is with a set of expanding t gauges. Install the original bearings and cam caps with the caps removed and torque them down to spec. Use the expanding gauge to measure horizontal diameter and vertical diameter. Swap with the other bearings and perform the same measurements. If they're the same, you're good to go. Hopefully someone can chime in with how Kawasaki does their bearing sizes for more clarification.

I just looked at a parts fiche and there is only one part number for the "camshaft bushing". That tells me that they're all one size. However, I would still perform the measurements to be sure you don't have a zero tolerance bearing somewhere.

On another note, gashes and surface degradation on the surface of the cam bushings is a sign of a problem. This tells me that you at one point had low oil pressure, which allowed the cam journals to come into physical contact with the bushings. That, or the engine was running with some seriously dirty oil.

Hope this helps.

Kellyn

[Mekial82kzp]

The book says to use plastigauge which I haven't seen any anywhere. but gouges are never a good sign... the cam journals are fine and in spec... and overall ware patern is about the same except the the ones on the bike with it's gouges/scratchs...

[A2 turbo]

The book says to use plastigauge which I haven't seen any anywhere. but gouges are never a good sign... the cam journals are fine and in spec... and overall ware patern is about the same except the the ones on the bike with it's gouges/scratchs...

you should be able to swap inserts with no problem but using plastigauge is best you should be able to get it at yor local napa or other auto parts store but you have to ask for it its not on the shelf

[RichLockyer]

Does the 1000 have inserts/cam bearings? My WR250F and the Honda CB750s don't... the cam rides on the aluminum journal, which is line-bored with the caps in place.

[A2 turbo]

Does the 1000 have inserts/cam bearings? My WR250F and the Honda CB750s don't... the cam rides on the aluminum journal, which is line-bored with the caps in place.

thats the nice thing about those old kaw's we used to line bore our suzuk 11's and use the kaw inserts they had the same cam journal diameter