Cam chain slack, timing off
 

I've been having weird idle problems and took the valve cover off to check clearances, noticed that timing is off -- maybe 10deg or so.

This is the first time i've inspected a cam chain on a motorcycle so im not totally sure what I'm looking at. It looks to me like its stretched, the links aren't really aligning with the sprockets.

Does this mean I have to replace the chain? I have a manual tensioner, maybe i can loosen it, reset the timing, and put tension on til the chain sets right?

If i do have to replace it -- I've been looking at the service manual and it looks like a bitch. Clutch, water pump, oil pump, etc etc. Looks like easily a whole day if not two, if i do the right thing and take the time to inspect other parts (especially clutch). Is it as bad as I'm thinking?

It is possible your chain is worn that bad. You can measure it according to the manual's specifications to see if it has worn and someone moved the intake cam to try to compensate for it. If the chain is within spec then button it back up and readjust the manual tensioner to verify it is correctly set. If you need instructions they are available here.

If you bought the tensioner my phone number is on the card, if not, PM me to get it if you want to talk about this more.

Hmmm i'm not seeing any sort of spec for the camchain in the service manual....

I have found that it's not unusual for the cam sprocket marks to not line up perfectly and exactly parallel to the head surface at the appropriate crankshaft location. I'm not sure why that is, but I found it to be the case in my 4 different KLR600/650's and with my KLX. Don't get me wrong...they're close but not precision like a timing mark on the crank designating TDC. It's probably due to there being a tensioner and a certain amount of required slack to operate properly.

Now, that isn't to say that your situation doesn't involve a stretched chain, a bad tensioner, or a bad cam reinstall after service. I'm just advising against looking for absolute, perfection in the cam sprocket alignment to the head with the proper crankshaft position. Is there a chance someone else did the Marcelino cam timing mod to your bike?...just asking.

All that said, these cam chains can wear out before their time if the OEM tensioner has been weak. I wore mine out in about 20K because of this and installed a new chain and klx678's manual tensioner at the time. Fortunately, my cam chain sliders and sprockets were not worn. Also if I recall...it's been awhile...all of the steps in the manual aren't necessary if you study the setup closely when you pull the right cover assembly off. I wish I could remember the exact scenario, but a light bulb went off in my head when I was replacing mine, and it allowed me to remove and install the chains and bypass one of the major elements.

Yeah, not surprised the index marks wont always line up exactly but this is pretty clearly out, no? I mean it looks like if i rotated the intake cam counterclockwise by 2 sprockets the index marks would be dead onhttps://cimg9.ibsrv.net/gimg/www.kaw...563edd55ac.jpg

I'd almost bet a nickel if you scoot that cam over a tooth in an attempt to rectify what appears to be improper cam timing, you'll find the mark to be below the plane of the head surface instead of above like it currently is in your pic.

You didn't mention the status of this bike. Is the cam chain rattling noticeably? Have you owned this bike since new and are aware of all its service history? How many miles on the bike?

i just got paid so for a nickel id be willing to take that bet

the deal with the bike... how much time do you have? its my first motorcycle, got it from a guy who seemed to know what he was doing and knew how to maintain bikes. its a 2009 with 19k miles but had bill blues 351 kit, tm33, engine overhaul done ~5k miles ago.

since i got it i found its been fouling plugs, running rough especially at altitude, soot in the tailpipe, terrible idle (inconsistent speed, hanging, dying). ive broken 2 metering needles in the carb -- sheared at the clip that retains it in the slide. i just got finished rebuilding the carb, i reckoned the slide was really worn and shaking around in the body of the carb wearing out the needle clip groove. replaced the slide, jets, needle jet, a few misc parts. actually after dicking with the carb a whole lot over a month or two i gave up and sent it in to bill and he rebuilt it...

havent noticed cam chain rattle (as far as i can tell being my first bike), valve noise, or anything out of the ordinary... actually one thing i notice is that when i blip the throttle (like a hard blip) i can hear a click from the engine. cant really hear it when im riding, only in my garage... but i could easily be missing noises that im just interpreting as normal motorcycle noise

whole time ive been figuring its just tuned rich, but now im not so sure. dude that owned it before me (only owner) said he's never fouled a plug in the years hes had it. i live at the same altitude and ride in similar places.... ive reached out to him about maintenance history but the basic answer is "I dont know man, never seen problems like these, i did all the regular maintenance"... all in all it runs, just not very well. ive put around 500mi on it, but ive gone thru spark plugs like crazy, get weird throttle response a lot of the time, and it has to idle at minimum 2000rpm

its got the Krieger manual tensioner, but i cant quite figure out how it works. the knob and jam nut on the end of the threaded rod back out freely without turning the rod. theres a hex-head nut looking thing on the body of the tensioner but it seems like its not meant to turn? i really wrenched on it

should i expect the cam chain to be completely seated in the gears? i can see daylight between the sprockets on the left gear, but the teeth look okay.... the chain seems tighter than i would expect, but hard to tell with the chain guard above it

i took valve clearance measurements tonight and they dont look good.

Exhaust (drivers side valve) - .18mm
Exhaust (passenger) - .09mm
Intake (driver) - 0/interference
Intake (passenger) - .051mm

The service manual specs are
Exhaust .15-.24mm
Intake .10-.19mm

Here are the cams at TDC... looking a little wonky? that exhaust lobe is basically pointing at the parting line, the intake lobe is pointing above it. harder to see in the photo i guess
https://cimg4.ibsrv.net/gimg/www.kaw...10c5275b6c.jpg

Now, after reading about your jetting problems and seeing a better picture of the drive, it is readily apparent the intake cam is off by 1 tooth. Move it, put it together, readjust the tensioner per the instructions, and run it. I don't see any problem other than that. I fought with getting the cams in my bike properly positioned. Seemed every time I'd move it I'd either move it one tooth too far or the wrong direction. Took me three tries, but I got it right on the third try.

On jetting I don't know if that one tooth difference would affect your carburetion that bad, I did the Marcelino Cam Mod and didn't change jetting, being close enough. Are you running the CVK carb? Odds are you should run a 38 pilot and if it is the N1-TC needle try the 2nd notch from the top of the needle. Set the idle mix screw at 2.5 turns out to start.

On the Tensioner, that allen nut should be locked down tight on the end of the adjuster bolt by that jam nut. They are only there to use as a thumb screw with your fingers, then to hold the adjuster bolt in place with an allen wrench while tightening the locking nut. You use your fingers to turn the adjuster bolt (when cold), then use an allen wrench to hold the bolt in position when tightening the lock nut against the body. A fine tuning method is in the instructions if needed. Email me at kriegercct@clems-garage.com and I will mail you a hard copy of the instructions and phone number. I did give you a link to the instructions in response to your previous post if you missed it.

The cam chain measurement is given in the service manual in the Engine Top End section, is measured over 20 links (21 pins from first to last) the maximum recommended length pin to pin is 128.9mm.

klx678, I know we're studying a pic over the internet, so yeah, the cam tooth with the timing mark might go down one link toward the surface of the head and be "better" aligned. It's worth a try. OP, are you mechanically inclined enough to do this or are you going to have to seek out a mechanic? If you can do it, it's a no-brainer to at least try. It sounds like you've already gone through a litany of other issues, so you might as well eliminate this one.

I'm assuming that you've received your carb back from Bill and installed it. Did that help with fuel fouling the plug in any way?

Hey guys, thanks so much for your feedback. I'll move that cam. I'm assuming i just have to remove the chain guard, loosen the chain, lift it off the sprocket, rotate the sprocket

Man, im not seeing the spec for cam chain length in my service manual. Have checked section 5 (engine top end) and section 2 (periodic maintenance). I can't measure 20 links without taking the chain off (it wraps around the sprockets in that length). I'll try 10 links at 64.5mm when I get home

On the carb -- I have the Mikuni TM33. 140/40 main/pilot jets, as recommended by Bill. I have other sizes i may experiment with later. Not totally sure if the rebuild solved my plug fouling. I've only ridden it about 90mi since i reinstalled. Pulled the plug and it looks good. I've fouled plugs in less than 90mi before, so promising but not definite.

Mr Krieger -- sorry, I swear im not mechanically illiterate, but still not following. What I think youre calling the allen nut can only be used to tighten the adjuster bolt IN -- if i back it off it just screws off of the bolt. If i'm following, I need to get the PB blaster out and unstick that stuck nut, and then rotate the adjuster bolt out by finger?https://cimg8.ibsrv.net/gimg/www.kaw...1cd6aab258.jpg