1985 XJ700X valves

Is the XJ700X a zero clearance motor? I just picked this bike up and will not start so I looked at the timing and the timing is way off so I will have to put it back in time. I am hoping that the valves didn't get bent. Any or all advice would be appreciated.

 

OK so I took the coils and thermostst off so I could remove the valve cover off and looked at the actual timing marks and everything seems to be in time, but the lobes on the cams aren't straight away from the valves. with #1 cylinder at TDC and timing marks lined up properly, the lobes on the exhaust cam is at 10 o'clock and the intake lobes are at 2 o'clock in comparrison with the perspective valves on #1 cylinder. I did notice the hole in the cam for the timing marks are on #3 cylinder, could it be the cams are in bacwards? I tried getting a compression check on #1 cyl and no compression at all......... I am stumped.

 

Do you have a manual?

The crank does 2 revs for every rev of the cam so every other revolution of the crank, the mark in the cam is 180 degrees off.

It is impossible to get the cams 180 degrees out of time with the crank if you have the marks lined up BUT You CAN get them 180 degrees out from each other if you simply use the bigger hole in the cam that goes all the way through and that will cause a problem.

There is a little dot (center drill hole) on the cam gear boss that should point up on BOTH of them at the same time (TDC #1) and the T mark.
(if you want, I'll take a photo and post)

Don't overthink the lobe position (it will give you a head ache).
With the crank at TDC, you have 1/2 rev of the crank (1/4 rev of the cam) before the exhaust starts to open, and 1 rev of the crank (1/2 rev of the cam) before the intake starts to open. AND remember, the top of the lobe would be the middle of the stroke...
Make sure both marks are up and timing mark on crank is T

It doesn't hurt to confirm that the timing mark is actually TDC on #1 (put a screwdriver into the hole as you slowly turn the crank to make sure it is really at the top when you hit the T.
The 86 used a different timing mark than the 85 and if the disc got swapped you are going to be baffled....that is doubtful since the valve would crash if that was the case and you couldn't turn it.

 

Thanx for the info Mike I will be working on it more tomorrow and I am going to try to evaluate the compression issue. I don't know why there isn't any compression at all. The needle on the guage barely mores but doesnt build any pressure. I am going to try another guage soon.

 

Throttle wide open, charged battery, good fit on plug holes, check valve on gauge working?
all plugs out, ground them so don't cook electrical

 

Mike,
I tinkered a little bit with it this morning and found that a standard set of feeler guages won't work. But with the timing marks all lined up I checked the only lobe that I could on #1 cyl and it was exh. = .011" and I couldnt get even a .002" in the intake. I will be getting a different set of guages soon I hope. Every autoparts store in my area only carried the std set. Could the tight clearance on the intake cause the loss of compression?
I am also finding it hard to find the adapter for my comp guage. I will post more when I know more.
Thanx, Chris

 

I gave up looking for a set of feeler gauges and just ground mine (narrower) with a flap disk on my grinder. They need to be a bit narrower than 3/8"
I also bent them a bit to make it easier to slip under the cam (very gradual in a couple spots).
You need a set that goes down to .001"
YES, if the valves are too tight, they may not close and thus get no compression.
If you add a little oil to the cylinder and then retest with much better results that would indicate ring problems (and you are bumming)

The plug holes are 12mmx1.25 thread

 

get yourself a compression guage and take some readings. That'll tell you quite a bit.

I just did this and am in the process of redoing the top end on a spare x engine...btw, thanks to mike for all his help thus far, minus the hint he gave me on the valve spring compressor, jk!

 

Mike
I checked the clearances on all of the valves and the results to the best of my capabilities are....
#1 cyl
int .0015 or less
.001 or less
.001 or less
exh .011
.010

#2 cyl
int .001 or less
.001 or less
.001 or less
exh .010
.010

#3 cyl
int .001 or less
.001 or less
.001 or less
exh .010
.010

#4 cyl
int .001 or less
.001 or less
.001 or less
exh .010
.010
all measurements are in inches. the smallest feeler that I could find starts at .0015 so I am assuming the .001s.

I will pull the intake cam out and find out which pads are installed and will post them as soon as I get them.

Any further suggestions will be appreciated.
I will PM you my cell number if this will help instead of the posts all the time. If I need smaller pads I will need to find some somehow any suggestions?

Thanx
Chris

 

Chacal has them...and some of us have a stash of extras BUT many of the extras are probably the same size as what you have currently. Most of mine are all 180-205
I would GUESS you will probably end up needing 165-175s (but just a guess)
I assume you have the fit chart in the manual.

keep your fingers crossed that the valves fix your compression issue and you don't have bad rings too.

Be carefull when removing the buckets. The shims like to stick to the underside of the buckets (which is kind of good)...just don't drop them down the engine!
I'm am against using magnets on the buckets and suggest a valve lapping suction cup to pull them out (if you happen to have one handy)

 

Mike,
I got the cam off and the pads are as follows,

#1 cyl
192
182
188

#2 cyl
190
195
195

#3 cyl
192
190
190

#4 cyl
192
185
198

I do not have the chart or a manual to find out the ones that I need would chacal know what I need? I can press all of the valves open with my thumb with a considerable amount of pressure. The valve on #2 cyl closest to the cam sticks open when the bucket is on it but when the bucket is off it seems to be fine. I will try to pm chacal about the shim pads.

Thanx

Chris

 

Harold has an elegant shim sizing spread sheet on his web-site
http://www.maxim-x.com/pix/valves+shims ... le(excel97).xls

The web page is
http://www.maxim-x.com/notes.html

See what you need and report back. Maybe you'll get lucky.
I don't have anything smaller than 182 in my collection anymore.

 

Mike,
With the calculations receivedfrom HAPs chart, my pads need to be.....
#1 192 to a 175
#2 182 to a 165
#3 188 to a 175
#4 190 to a 175
#5 195 to a 180
#6 195 to a 180
#7 192 to a 175
#8 190 to a 175
#9 190 to a 175
#10 192 to a 175
#11 185 to a 170
#12 198 to a 185

i figure i will swap #2 old over to #5 and #11 old over to #12.
I will end up needing....
1--165
1--170
7--175
1--180

is this what you would recommend? Also would it hurt to check the compression on the cylinders without the pads on the intake side? This would allow all of the valves to be totally shut for the compression check?
Or should I wait for the proper pads and clearnace?
I will be sending out a check and request for the XJCD soon.......
Thanx Chris

 

You can't check the compression without pads on the valves. The intakes wouldn't open and allow any air to go in (take) to be compressed so your numbers would be skewed.

If you want to "putz" you could take your three smallest shims and put on one cylinder at a time and see what your numbers look like.

It's VERY odd that all your intakes are extremely tight and exhaust is within spec.....Are you SURE you aren't pushing the valve open with the feeler gauge? Once you get over about .008 the feeler gauge is stiff enough to wedge between the cam and bucket and force the valve open with a little force.
Now is the time to double check (you don't wanna do it again)

Many dealers will have an assortment of shims in the service department. Some of them will trade you for a nominal fee. They take the same shims as many of the FZ engines (with the genesis head)

 

Mike,
I will try the putting the three smallest on each cylinder at a time and see what I get.
When it comes to the exhaust valves I didn't feel any resistance until I tried inserting the .011" ...all of the rest were very easy just oil resistance. Thank you for all the help. I am usually pretty good at these things but this bike has me baffled. I guess it would help if I had the manual or the XJCD.
Thanx
Chris