!PROJECT! KZ650 Cafe racer

[Dan-O]

Wow, what a great thread.
Got a bunch of good ideas.

I followed every post, all 10 pages.
(now 11 pages)
I'm new to the site but not new to old school KZs.
I had a '77, sold it, bought a newer cruiser, sold that to buy a convertible the whole family could enjoy and just last week bought my old KZ650 back.
My buddy still had it.

I had it cafe'd out but converted it back to mostly stock when I sold it.

Thanks for sharing all the updates!
Dan-O

[zeiss150]

I Haven't posted in a long time because I got burnt out on my bike... Yes, it happens. So I started working on it again and I decided to re-check my static timing so I pulled off the carbs and the valve cover and rotated the crank to 1-4 T mark and I counted the links and it is 36 just as its supposed to be. BUT... the exhaust cam link (the link the -----> points to #0) is one link above the edge of the head. And the exhaust cam link is one link below the edge of the head. So I thought to my self, "well there's the problem".

So I pulled the cam's off, set the crank, pulled the cam chain tight so that there was no slack on the exhaust side of the engine, put the cam's back in and counted 36 pins back.

EVERYTHING LINED UP PERFECT!!!. So I torqued the cam towers down and checked all my timing marks again and it still lined up!

Now here is where I get ****SSSSSSSSED and frustrated.
I turned the crank, and there was no slack in the cam chain (because the exhaust cam moved with the movement of the crank) So in my mind all was well.... NOT!

I continued to turn the crank until the timing marks lined up and sure enough, they were off when the crank made 2 full revolutions.

If I line up the cam chain pins with the edge of the head, the crank timing mark is about 1/8 of an inch off (What I would guess is about one link).

WHAT THE HELL MAN!!!

Just in case you were wondering yes I did make sure the cam chain tentioner was properly installed before I made two full revolutions.

I think this is the root of all of my problems with the motorcycle. Why can't I fix this? Is there more slack in the cam chain than what the tentioner can take up? What am I missing?

HELP!!!! I want to ride my bike again.... HELP!

Thanks, Matt-

[Mike900]

From the right side of the bike are you turning the crank clockwise or counter clockwise?

BTW - I've never heard of this referred to as 'static timing'. I simply call it cam timing. Static timing refers to setting the ignition timing without a timing light. Someone correct me if I'm wrong.

[klx678]

Originally Posted by zeiss150

I Haven't posted in a long time because I got burnt out on my bike... Yes, it happens. So I started working on it again and I decided to re-check my static timing so I pulled off the carbs and the valve cover and rotated the crank to 1-4 T mark and I counted the links and it is 36 just as its supposed to be. BUT... the exhaust cam link (the link the -----> points to #0) is one link above the edge of the head. And the exhaust cam link is one link below the edge of the head. So I thought to my self, "well there's the problem".

So I pulled the cam's off, set the crank, pulled the cam chain tight so that there was no slack on the exhaust side of the engine, put the cam's back in and counted 36 pins back.

EVERYTHING LINED UP PERFECT!!!. So I torqued the cam towers down and checked all my timing marks again and it still lined up!

Now here is where I get ****SSSSSSSSED and frustrated.
I turned the crank, and there was no slack in the cam chain (because the exhaust cam moved with the movement of the crank) So in my mind all was well.... NOT!

I continued to turn the crank until the timing marks lined up and sure enough, they were off when the crank made 2 full revolutions.

If I line up the cam chain pins with the edge of the head, the crank timing mark is about 1/8 of an inch off (What I would guess is about one link).

WHAT THE HELL MAN!!!

Just in case you were wondering yes I did make sure the cam chain tentioner was properly installed before I made two full revolutions.

I think this is the root of all of my problems with the motorcycle. Why can't I fix this? Is there more slack in the cam chain than what the tentioner can take up? What am I missing?

HELP!!!! I want to ride my bike again.... HELP!

Thanks, Matt-

Entirely possible the tensioner may have reached the end of travel. One way to tell might be to remove the tensioner body, pull the cam chain tight on the exhaust side like you did, then push a rod or screwdriver or something in the tensioner opening and see how far it must push in to take out whatever slack you can by pushing in. Measure the distance and see if it is more than the tensioner will allow.

If it still has good travel, clean it up to make sure there's no gunk in it stopping it from moving. I hope you can take care of the thing.

I will tell you most people racing those engines, and most others for that matter, use a manual tensioner. If you decide you want to use a manual unit, they are available for your bike or you can make one. It will take a drill press, a drill press vise, a tap and die set, and and some 1/2" aluminum plate. Measure up the original, drill mount holes and the tensioner bolt hole, tap the hole, add the bolt and lock nut, install and adjust. Other choices range from buying one from some manufacturer, if they make one for it, for $51, or buy one I make for $30 (including the OEM gasket). The same tensioner fits virtually all in-line 4s from 650-1000cc from 72-83 and the Zephyr 750 (I made them on request by a member of the Zephyr Zone for 3 of them, he posted on the Zone that they worked well).

If you're a do-it-yourself kind of guy, make one. Otherwise it's hard to beat $30 for a manual unit. PM me if you want to check out one.

I ended up doing tensioners because both my KLX and Zephyr had them go bad, as had many other KLX owners in the Yahoo KLX650 group. When I made mine I made 4 extra and kept going from there. I like making them for those who either don't have the resources or time.

[AgentBauer]

That's pretty damn slick. I am turning a KZ 750 G into something cafe racer-ish myself. Your devotion to this bike is inspiring. That gold on the frame is offensively badass.

[zeiss150]

Hi klx678, I have a manual tensioner on the engine now. I set it just the way the book told me to and it still isn't working. I'll try re-adjusting the tensioner and see if anything changes.

Thanks for the compliment, agentbauer

Mike900, I'm turning the crank CLOCKWISE, if I turn it counter counter clockwise then i could totally see my problem happening. So I'm still stumped by what is causing the slack on the "exhaust" side of the engine.

Also mike I just called it static timing... I'm sure you're right that that's not what its called.

Thanks for the help guys, keep the ideas coming!

Matt-

[kawpaul]

You can check your chain to see if it has stretched beyond it's service limits. According to my manual you measure the length of 20 links. They should be the same for the 650 as the 750. My manual says service limit is 128.9 mm with chain pulled with a force of about 5 kg.

[Mike900]

I'm not seeing how chain stretch could be the problem unless the chain had jumped a tooth & I can't see that going unnoticed. If it looks like it's off less than a link then I could see chain stretch being the problem. My guess is the chain just wasn't sitting correctly on one of the chain guides. Try it again & see what happens.

[zeiss150]

Hi Mike900, I will absolutly try it again, and I'll take pictures this time. I'll have pictures up tomorrow.

Thanks, Matt-

[tonyg]

did you give up on this one ??

[zeiss150]

WHEN HELL FREEZES OVER! I've got way to much time and energy invested in this bike. Also I LOVE riding it. I just need to fix this one annoying problem. I'll get into it tomorrow.

Matt-

[Torques]

Good job!

[kopcicle]

Back again Matt ...

Adjustable cam chain sprockets .
If you haven't done this before I will elaborate . You will need a dial indicator , a degree wheel and a positive stop that you can insert through a plug hole with out interfering with the valves . The older link type cam chains were of varying quality leading to early approach to service limit as mentioned above . Even new chains advertised as pre-stretched will lengthen in the bike after very few miles . Feel free to pm or IM me if you need any assistance . It's entirely possible that you may have to elongate the holes in the sprocket yourself . This is an accepted and often used fix for these bikes but first check to see if the chain is worn beyond service limits ,

~kop

[zeiss150]

So I took the valve cover off today and I turned the engine over 2 times and lined up the timing marks and this is what it looks like....

here's the timing mark perfect.


This the exhaust side arrow... its about one link to high


and here is the intake side... about one link below the edge




If I turn the crank so that the timing marks on the cams line up with the edge of the head like there are supposed to this is what happens....

exhaust side


intake side


crank timing marks



Its off buy about one link.

So you might be saying well just set your cams right... I DID! it was perfect when I set it ... this is the 3rd time I've set it .... so now I think I'm going to put the timing mark on the "F" and set the cams in so when I turn the crank it will be perfect.

Kop, Thats a great Idea about the degree wheel but I don't have one. And I'm not that sure how to use it any way. I read up on how to use it for my 1972 Datsun 240Z but its a single over head cam and I don't really know what I'm doing, so I'll just try it buy setting the timing a little forward.

I'll let you guys know how it go's.

Matt-

[zeiss150]

I'm a sucky mechanic. I cannot for the life of me figure out what is messed up with my motorcycle. I've checked the three basics

Compression .... Check, I have that on all 4 cylinders

Spark.... Check, I have that on all 4 cylinders

Fuel .... Check, The carbs were working fine when I took them off.

I have 12volts at the coils, I have the static timing for the points set.

I quadruple checked the cam timing and its fine. Where am I going wrong?

I'm wondering if when I took the carbs off a month or so a go the gas has gotten old and messed up the jets... but a month.... that should be long enough for gas to go bad.

I'm very close to taking it to a mechanic and having them sort if out. Anyone go any ideas?

Thanks Matt-

[sbc1320]

The T mark is for putting motor in time as in valve timing with cams and number 1 piston at TDC. The F mark is for timing motor with timing light for ignition system. Sounds like you are not pulling chain tight enough when putting chain on exhaust cam. On my KZ900 Clymer manaul for mine says with exhaust cam marks parallel to head surface, with the pin on chain that is parallel or just above the mark, start counting with the next pin after this one. My bike calls for 28 pins after to time to my intake cam. Hope you get it and you did a great job on the step by step posting and on your bike. Hang in there.

[StarGate]

Originally Posted by zeiss150

Fuel .... Check, The carbs were working fine when I took them off.

Where am I going wrong?

I'm wondering if when I took the carbs off a month or so a go the gas has gotten old and messed up the jets... but a month.... that should be long enough for gas to go bad.

I'm very close to taking it to a mechanic and having them sort if out. Anyone go any ideas?

Thanks Matt-

Are you saying the fuel is fine because the carbs were working when you took them off a month ago or have you verified the fuel is getting to the plugs now?

Fuel can go bad in a month under the right conditions. Don't assume anything is right just because it "use to be". Making assumptions when trouble shooting a problem is the leading cause of male baldness today.

[kawpaul]

So did you measure the chain for stretch limits?

[Mike900]

What happens when you try to start it? Does it seem to be totally dead or is it close to starting?

Make sure neither fuel line is routed above the bottom of the fuel tank. I had one too high once & they sure start hard when only two cylinders are getting fuel. That cost me a Sunday afternoon.

Make sure the spark plug wires are going to the correct cylinders. Assuming it’s the same as the 900 then 1 & 4 go to one coil, 2 & 3 to the other. You also need to make sure the coils are are plugged into the correct set of points. That could be reversed if the lobe on the ignition advance was put on incorrectly.

[antiq]

Try moving the exhaust cam back just one tooth then reassemble and check. The tensioner will pull the chain tighter than yo can by hand.