Valve Adjustment the DIY Way !!!

[ads007]

Valve Adjustment the DIY Way !!!

I recently did my very first valve adjustment on my ZRX that I bought used
and had no good idea when they were done last. The bike has 33k. I did a lot of
research before starting - found some good info but there were still some things
that could have been better, so I decided to take some pictures and do this
write up.

Taking off the gas tank was easy enough. I did not drain the coolant. I
opened up the bolt that holds the thermostat housing on the left side of the
bike and pulled the whole thing up, out of the valve cover's way. I pulled the
upper coolant hose off and zip tied the other out of the way.

Once the hoses and wires were out of the way I pulled off the
valve cover from the left side. Needless to say you have to be careful with the
rubber gasket so as not to break it. I took the spark plugs off and stuffed rags
in the holes to prevent anything from falling in.

There are spark plug cover seals around the spark plug holes, be
careful not to tear them. I ordered replacements for mine as they were kind of
hardening. Dipped them in oil before putting them back in.

I measured the clearances between the shim and cam lobe with the
lobe pointing 180 degrees from the shim. I rotated the cams by the rear wheel in
5th gear. The rags in the spark plug holes keep popping out when you rotate the
engine due to compression so keep an eye out for them. Having a head lamp or a
light hand really helps when looking into the engine and taking measurements.

I wrote down all my measurements and removed the shims that were
out of spec or too close to being out of spec. I removed the shims by sliding
the rocker arm sideways (they are spring loaded) and using a cheap extendable
magnet thingy I bought for a few bucks at Autozone. The shims come out fairly
easy. Shim diameter is 9.48mm. I measured each shim for thickness. Did not want
to rely completely on the numbers printed on them.

I wrote down my measurements on my valve sheet and taped each shim I took out in
the respective place on it. Completed my calculations on the computer and
figured out if I could re-use any shims I had. I was able to re-use 8. I ordered
a refill kit for the rest - $35.00 on ebay. It came with 5 of each size. I just
needed to order 1 more to complete what shims I needed. Total spent on shims was
about $42.00 with shims to spare for next time.

Putting the shims back in can be tricky. I used some grease to stick the shim to
my finger and place it carefully on the shim bucket. I fine tuned the setting
using a small screw driver. You have to be careful not to apply too much
pressure so you do not scratch anything. Once they are in the right way they
will slide in the bucket real easy.

After putting the shims back in I re-measured the clearances to be sure I had
them in right. Double and triple check that everything is in there properly
before closing the valve cover. I cleaned off any dirt and grime from the valve
cover contact patches and used some RTV silicone on the cover. Tightened
everything back up and let the bike sit for 24 hours before starting to let the
silicone dry completely.

Came back the next day - started the bike and took it out for a ride. Runs like
a dream and I know I done it right.

So, all in all - valve jobs are easy on the ZRX. Take your time and get your
hands dirty

One more thing - I have read not to rotate the engine with shims out - I don't
know why ? I checked with my buddy who is a certified motorcycle mechanic and
owns his shop, he said it makes no difference. I rotated the engine with the
shims out and have had no issues at all. I made sure to move the rockers back in
their place before rotating though. Any insights?

 

[Dirty Harry]

One thing I found helpful was to rotate the shims when they are "seated" to see if they rotate freely using a metal pick. If inserted correctly in their buckets, they should; if cocked at even the slightest angle, they will not rotate at all. I had a couple of shims that appeared to be properly seated, but were not. I made the discovery when the clearance was way off after replacing a shim with the proper size (WTF???). Once I discovered the cocked shim, it all made sense and the world was right again

[Timan]

Wish I had known it was okay to rotate the engine w/o shims. I could have closed mine up 2 days ago, instead of waiting for shim kit. Great write up!

[zrx24]

Wish I had known it was okay to rotate the engine w/o shims. I could have closed mine up 2 days ago, instead of waiting for shim kit. Great write up!

The main concern is doing damage (minor or otherwise) to either the rocker arm surface or shim bucket. When the cam lobe pushes the valve down via the rocker arm on the shim there is quite a bit of force exerted. Without the shim in place the force is being taken by the corners of the shim bucket, which apply point loads to the face of the rocker arm. Point loads are usually not a good thing. Just because the parts are metal doesn't mean they can't be scratched, bent or damaged in some way (minor or otherwise).

And there are also people that rotate the engine by use of the starter button, which with the higher rate of rotation adds an impact load to the equation as well.




So it's not to say you absolutely can't rotate the engine without the shims in place. It just increases the possibility of marring the surface of the components that operate under relatively tight tolerances.




Oh, and as for a "certified motorcycle mechanic" saying it's ok to do this. Well, all I can say to that is I've had more than my fair share of "certified motorcycle mechanics" screwing my shit up.

[zrx24]

Nice writeup, ads007. Thanks for going to the trouble.


This definitely needs to be made a sticky.






A lot of the "old timers" on the board often times forget that even with the Rex being around for over 10 years now, there are still "noobs" to the bike looking for information that to many here is second nature.

[Wolfman]

Good write up.
I will add, I never take any hose loose. Might also want to check the lobes for pitting while your in there. (namely the #4 intakes....seem to be the most prevalant)

[ads007]

Thanks guys. zrx24 makes a good point about the rocker damaging the shim bucket. It is possible - I was very careful about that. I went extremely slow and made sure that the rocker was not going to bind with anything.

Using the starter to rotate the engine does seem riskier if you are going to be doing this with the shims out.

One thing I forgot to mention was that my friend did tell me not to rotate the engine with the starter. Something not in the right place = something damaged

Also if the lobe is putting any pressure on the rocker when you try to slide it out - thats not fun - the shim will very likely fly out of the bucket - so don't do that

[Wolfman]

One side note. "IF" you pull a hose, remember to bleed the air from the cooling system.

[RedRex02]

why rotate the engine at all, just set it at #1tdc then check I&E #1, I#2 and E #3, set clearance for those that are out then rotate 180* and check I&E #4, I #3 and E #2, pretty simple without risk of damage unless you stuff a rag in the cam chain hole and forget it like some here have done.
BTW, you can remove the valve cover without draining the coolant and removing hoses.

[chris russell]

yep,second vote to stickie this.


good write up with good clear pics..........chris

[REXNFX]

awesome! thanks for taking the time to write this up. I do my own valve adjustments as well. It saves me from having to buy an equivalent to another used motorcycle each time. those 7500 miles roll around rather quickly!

[REXNFX]

awesome! thanks for taking the time to write this up. I do my own valve adjustments as well. It saves me from having to buy an equivalent to another used motorcycle each time. those 7500 miles roll around rather quickly!

[ads007]

Yes sir - 7500 miles roll up quick. Is it a norm to stick to the 7500 mile intervals or can one go longer as the miles roll on?
I think the zrx is the only Kawi that wants valve check every 7500 miles. Isn't that one reason why most of us don't buy Ducatis.

[zrx24]

Is it a norm to stick to the 7500 mile intervals or can one go longer as the miles roll on?

The valves on the Rex seem to "bed in" by about 15k, with most the adjustment needed in the first few thousand miles. At 33k it's been quite some time since I've had to swap out shims.

I still check clearances though at the called for intervals just to be safe. Having removed all the smog crap and learning that I can do it without having to drain the coolant makes the exercise MUCH less involved.

The hardest part about it for me is removing and replacing that dang heat shield.

[Timan]

Speaking of the heat shield; what does it hurt to just leave it off? It really is a pain.

[Wolfman]

I take mine off for the winter, but reinstall it for the summer. One ride in this Mississippi heat in July will make you remember why you should keep it installed.
But to answer your question, no, it will not hurt anything to leave it out. It will cause an increase in heat to the fuel, as well as your thighs in summer.

[Timan]

I have/had the 2 hottest bikes ever made. Hottest was 1985 BMW K100RS. I now have 2005 FJR 1300 which is pretty close. I put the shield back on the ZRX, but didn't enjoy it. Thanks for input; that hummer may noy go back on again.

[Mclarein]

yep,second vote to stickie this.


good write up with good clear pics..........chris

Done and done, Stuck to the top.

[feelergaugephil]

Great informative read.

[SonicGuppy]

A+

[Savage99]

Nice write up

[HarleyJohn]

Yes sir - 7500 miles roll up quick. Is it a norm to stick to the 7500 mile intervals or can one go longer as the miles roll on?
I think the zrx is the only Kawi that wants valve check every 7500 miles. Isn't that one reason why most of us don't buy Ducatis.

Nice work.

FWIW, I check my valve clearance every 20,000 miles (annualy) on the ZRX. I usually find 1-3 shims need to be changed. YRMV.

[jimmynewts]

Nice job on the write-up with pics. I just did mine for the first time and this made it easier. Other info on the OA (found by using the search function) also helped.

Mine has 17K and it was the first adjustment for me and the bike. Nine out of the 16 valves were out of spec on the tight side. Most were .05 mm to .10 mm out. The most common new shim needed was a 2.60 mm; next was 2.65 mm. No other sizes were used.

Here's what I found when doing the valves:

It was easier for me to drain some coolant and remove both hoses and the thermostat. This, along with zip-tying cables and wires up out of the way, gave me more room for my ham fists to work. More experienced mechanics may find this unnecessary.

I'm taking KWICK's advice and replacing all gaskets. Two of my four plugs were sitting in oil before removal, which means the plug hole gaskets were leaking. The eleven gaskets needed (1 VC, 4 plug hole, 6 o-ring washers for VC bolts) came to $85 shipped from ronayers.com). Even though my VC gasket came off clean, and seemed reusable, it's being replaced.

Since the plugs are coming out to facilitate compression free engine turnover, replace them as well. Plus, it's a little easier replacing the plugs when the valve cover is off. Not sure how to gap the dual electrode plugs. They all came new at about .025". The ones that came out of the bike were closer to .035", probably due to wear. I think I'll leave the new ones alone...

I used the #1 and #4 TDC method from the manual to adjust half the valves at time. The cam lobes do not have to point up at exactly 180 deg from the valves to check and adjust them. There is zero lift of the cams for over 100degrees of each revolution which gives the leeway needed.

I didn't use my centerstand so I was able to push-bump the engine to the right spot. Just pop and pull the clutch while pushing the bike forward and back about a foot at a time. Watch the lobe movement to verify TDC for a particular cylinder...both the exhaust and intake valves will be closed (lobes pointing approximately upward) with the exhaust cycling further around since they will be the first to open after TDC.

Don't rely on switching shims from another valve to replace ones that are out of spec. Have shims on hand before you start so you can replace them as you go. The smaller sized refill pack (2.40 mm to 2.65 mm) is probably the most used.

My feeler gauges were in .02 mm to .03 mm increments. This was adequate, but it would have been nice if they were in .01 mm increments between the sizes of .10 mm to .25 mm to avoid having to double up gauges for the in between measurements.

The telescoping magnet is ideal for removal. Some of the sliding rocker arms needed a little nudge from a blunt object before they would slide easier by hand. Some would rotate and catch on the valvetrain so they didn't need to be held out of the way for easier shim removal/insertion.

A flat screwdriver of the long narrow variety worked best for insertion. The working end was bent at about a 60 degree angle from horizontal (a photo of this is shown on another post about valve adj). This allows the shim to adhere to the flat (side) surface of the tip and not fall off with moly grease holding it in place. Both sides of the shim should be coated with moly grease before insertion. The tip about rotating them with a pick after insertion into the bucket is a good one to verify they are in properly, since they sit a little higher than the bucket itself.

All in all, this wasn't too bad of a chore for a valve adj newbie with some mechanical experience.

[Ropeman]

Great write up

Original post:

I measured the clearances between the shim and cam lobe with the
lobe pointing 180 degrees from the shim...

Correction: Clearances are measured between the shim and the rocker arm.

[Radical]

Great to have in history..Another lesson plan

[BonzRexster]

You guys can (and will, I am sure...) weigh in on this...

I had some oil wetness in my plug recesses when I did my valve check/adjustment. I did reuse the spark plug recess gaskets. Before re-installing them, I put them in the oven for a while, 250 degress or something like that, and softened them up, worked them around with my fingers after they cooled a bit, which in my estimation got rid of some of the "memory" of the rubber. In 500 miles since the valve adjustment, I have not a speck oil in the spark plug recesses when I checked last weekend. The long term will tell more, but just like it's pretty easy to see a leak from the valve cover gasket after just a few miles, I would suspect after 500 miles if there is no oil leaking, that's a good sign.

[gammer]

The pics in the original post are not showing for me. I know they were there a while ago, but gone now. Anyone else not seeing them? Just want to make sure its not something on my end.

Thanks...

[bigharry]

No Pics

[BonzRexster]

Didn't the site lose stuff when it crashed last year? That might be the issue...

[bigharry]

The pics in the original post are not showing for me. I know they were there a while ago, but gone now. Anyone else not seeing them? Just want to make sure its not something on my end.

Thanks...

Didn't the site lose stuff when it crashed last year? That might be the issue...

Gammer says they were there a "short while ago".