Cam timing

I had to haul the head today to put a helicoil in my #4plug as it blew out on the way to work this AM (took the day off to fix bike!). I set the timing advance to TDC on #4, removed the cams, etc (I have a shop manual and followed the instructions). When I put the head back on, I lined up the Ts and counted 36 pins between them. After it was together I tried to start the bike and no go! It doesn't even seem like it is getting gas. My prime is working. When I kick the bike over it sounds either like the cam chain or something is sparking off to something. Could I have timed the bike 180 out? Any help would be appreciated.

what type of bike is this? I am having a problem with mine, that is kind of the same. Half the time it wont start, but I already redid the timing in the same manor. When I can get it started it back fires like nothing else.

It is a 77KZ650C1. I replaced the head gasket at the beginning of the summer and I thought I did everything the same this time but no go. I've put the choke on and held the throttle wide open and then kick it over a bunch of times and when I pull the plugs they are dry. I just checked the timing and with my test light hooked up to the black lead the light should go on when the "F" of #1 are at the timing mark and the light went on when I got to #2. I switched plug wires from 2&3 coil over onto plugs 1&4 and vice versa still nothing. By the way I have a Dyna S ignition with Dyna coils (green).

I was thinking, if the engine isn't getting gas, could the engine be trying to draw air in through the exhaust and pushing air out through the intake?:blush:

Post edited by: letthegoodtimesroll, at: 2005/10/18 21:20

Does your cam chain sprocket(s) have arrows and punch marks and "IN" and "EX" marks on em ? If yes ? did you line em up per the manual ? Did you check the valve clearance's ?
You didn't turn/move crank when you took the cams/head off did you?
Another thing I recently discovered (learned the hard way) is the cam-cap bolts and how as one side is drawn down the presure can be un-even on the opposite side and bolt holes can be stripped out, this can happen if you do just one side at a time. The better way is to draw ALL cam-cap bolts down slowly and evenly.
If your engine was running good before the; "spark-plug hole incident" ? And now it won't ? Looks like it's time to go back over everything you did when you put it back together, right?

Post edited by: ~DW~, at: 2005/10/18 23:02

P.S. Don't know about your engine, but on mine?
you have to loosen up the cam chain tensioner (remove the 17mm cap and pull the cross wedge and its spring) before you take off the cam-caps. Also, you will know if yor cams are right with the world (at least on my engine, anyway) when number one cylinder is at TDC ? look at the cams from the right side of your bike. Are both the end notches pointing away from each other ?
If yes ? this is good.

Post edited by: ~DW~, at: 2005/10/18 23:21

When I retightened my cam caps, the forward bolt of the #5 was slightly stripped (Iwas scared to putt too much torque on it). Is a 1/4" bottoming tap the size to use? Any help would be appreciated. Thx.

I suspect you will want to use a bottom tap but a 6mm w/1.0 pitch. These are metric thread, not SAE. After chasing out the thread, you had best blow the hole out good with compressed air if you can. The 6mm bolts probably have about 10 lbs of torque so you don't need to crunch them down! See a manual for the exact spec on the torque...

George is correct.
Myself ? I took the 1/4 SAE option, bought grade eight fine thread, an inch and three quarters long and a tap (1/4"x 28 NF plug tap) at NAPA. It's not a bottoming tap, so I measured the hole depth with a WD40 tube/straw.
The 1/4 SAE will give you 6.35mm of bite and it fits nice and snug in the cam cap as well. Some blue loc-tite and a 7/16 socket and you can torque em down to book spec's..my engine takes 12 ft pounds of it.

Post edited by: ~DW~, at: 2005/10/19 20:35

I have found the problem! My camchain tensioner was not moving. When I put the head back on the other day, I installed new little rubber blocks on the guide roller axle and they were squished down so much they were pushing in on the sides of the tensioner assembly not allowing it to move freely. I took the head off again and "modified" the little rubber blocks abit and now everything works fine. I still don't have the bike running as I am waiting on carb jets that should be in today. I am getting better at this: total time from start to finish 4 hours without the carbs on, carbs would take another half hour. I don't know if anyone else has done this before, but what I used to put my valve buckets and shims in is an empty egg carton. I numbered the cups which allowed me to keep everything all together.

I didn't want to tell you to necessarily use a 6mm tap to chase out the threads. This will only be effective if there are threads to chase out. Always use a blind bore tap as it makes thread to the bottom of the hole. It is harder to start than a tapered tap since it is flat/square to the hole. A tapered tap can be used to start the hole then switch to a blind bore. If you go to the bottom with a tapered tap, you will lose 2-3 threads...

As far as what size to go if you need to enlarge the hole in the event the thread is gone... I generally like to go to the next size over the one I messed up... in this case 1/4" is smaller than 7mm and would be a decent choice. It gets to be a mess if you start mixing SAE and metric fasteners though... Some folks; especially folks who race, will just drill ALL the cam cap bolt holes out and use 8mm bolts. They will take a lot more snugging without ruining thread.

Glad you got the problem fixed and your suggestion for using an egg carton is a good one for a 650 owner or for anyone with shim under bucket style heads. For 900/1000 owners with shim over bucket, carefully record which shim is where so that when you make a measurement when doing a valve clearance check, you will know specifically what shim is needed and won't have to take them out to look...