Maxim-X shim check

I've done the shim check on my XJ650 and XJ1100 airheads but haven't done it to my XJ700XS Maxim-X yet. It appears I need to check that out, I just ordered the proper feelers from Len, they will be here any day, he always ships fast. Checking the shims shouldn't be a problem,

I'm trying to read up on all I can find about doing these shims, I have bought a spare engine ready to go with already done shims and was going to do any re-shimming in the winter and just swap engines to save myself rushing during riding weather but if I need to do this exchange myself, it's more than my 64 year old bod can handle alone with the lifting. So I need to at least check the shims to see if that is my issue with power loss at the upper RPMs and then also do a leak down test assuming the cam tolerances are correct.

Can I use the shim tool on the Maxim-X to hold down each of the 5 valves or do I have to use a different tool? I have to remove the cams to do the job so maybe a tool isn't needed and I just pry up the bucket to get at the shim at that time?

I read the proper Maxim-X clearances are mislabeled in the manual and they should instead be:

Valve Clearance Intake: 0.11 - 0.20mm (= 0.004" - 0.008")
Valve Clearance Exhaust: 0.21 - 0.30mm (= 0.008” - 0.012")

Details... details...

I've been looking for a really good walk through, with photos in order, for the first time doer of a X shim job so I don't miss anything. I found these links offered and they are helpful but the photos are grouped and alphabetical, not in sequence and what would be most helpful to me getting all the details right would be a list in order of step 1, step 2 with photos inserted at the relevant places.

http://xjbikes.com/Forums/viewtopic/t=16298.html
http://xjbikes.com/Forums/viewtopic/t=29661.html

I'd found this video on X shim replacement on Youtube but it isn't so much to educate, it was more of a visual of what was done after the tasks had been performed.



Any other known good links or suggestions regarding the X shim check & replacement?

Thanks,

Gary

 

OK, so I'm trying to check the shims on this Maxim-X and having trouble finding the proper location to set the marker on the pulley. On page 3-54 of the service manual it shows a photo indicating to line "T" mark on the timing plate with the stationary pointer. I'm not sure if that's where you are also supposed to have it set to check the shims. I can't however seem to find a place where all the cams are pointing away from the bucket as it would have when the cylinder is about to fire, so I will just get the points of the lobes straight up and measure the gap it that way.

I can't find the stationary pointer, it's not like the other XJ assemblies I remember. It looks like the stationary pointer is just a large screw hole that's unused. I looked on the above page and in the manual it looks like you're looking at a tab to line up with. So I looked at my spare engine and it does not have a tab there either, just a screw hole. Here's a close up of what I'm seeing, the white dot is reflection from the flash



Any suggestions as the the stationary pointer & also why I'm not seeing all cams for one cylinder to lift at the same time. I must be looking at this wrong.

 

Just finished my Maxim X and here is a pic of what you should see and the dots on the cams line up with mark on cam bearing cap on #3 cyl

 

1986 700-X models did not use a pointer.........

 

Toomanybikes, Thanks for the photos, they will help!

Chacal, thanks for that info. Odd, I guess they want us to aim for the screw hole. Maybe the few degrees of distance off might not mean a thing and the gap will be constant so it's not an issue with an exact line to draw next to.

Thanks for the answers.

 

Here's some tips I posted a little over a year ago when another '86 Maxim X owner encountered the same problem:

First off, do you have the Yamaha service manual? If so you will see the picture of the "Ignition Timing Check" on page 5 of the Supplementary Service Manual which is towards the end of the Manual (just before you get to the Appendix pages).

For the '86 models, Yamaha eliminated the pointer and re-positioned the marks on the rotor. And for your model, the T mark is supposed to line up with the notch on the upper pickup for top dead center.

Here's some links for reference:
'85 models
'86 models

Hope that helps.

Tony

 

For the clearance check you don't need to worry about the crank position, just the cam lobe position. It is a bit more fiddily on the 5-valve machines, but you still want the heel of the cam lobe positioned directly above the valve bucket that you are checking the clearance of. All of the valves on any given cylinder will only be closed on every other crank rotation.

 

Hey there Tony; I only have the pdf of the manual which goes to page 8-22 but no supplement, I just did a search and supplement is not attached to the PDF. Have a supplement for the airhead 700 but not the X. I'll have to go and look at the upper pickup for the notch, I was just rotating the cams so I'd get max clearance. When I got to Cyl 4, the intakes are too tight to slip a .004 feeler under so figuring this one out and getting the right shims to get going will take too long. I'm going to put that spare engine in and ride & then do the shims during the winter while I have plenty of time. doing some restoration with the 650 so not using it much and the XJ11 is upside down as I need to do the dremel fix on 2nd gear.

K-Moe, yeah, that's what I did but I'm not going to do the shims right now as I just mentioned, I'm amazed that they are so badly affected already, there's less than 10K on the engine. Now I need to learn how to best get that engine out with the least effort. Draining the oil, pulling the carbs tomorrow & undoing the driveshaft. No time like the present to get it done.

 

It's the line down the middle of the pickup, right above the space between the 1 and the - on the rotor in your pic.

 

Thanks. Looks like they moved the plate 90 degrees counter to do that.