[Cabanaboy]

About to solo my very first time checking valves on a 4 cylinder SS bike. I do have a repair manual to help me but I've never worked with shimmed valves before, so I'm a tad nervous.

What I have for the job:
1.) Hotcams Shim kit
2.) Viton Valve Seals
3.) Micrometer
4.) Feeler Gauges

I'm doing it on the CBR900RR, and I am unsure of whether or not I want to remove the motor from the frame, or if I have enough clearance to do it int he frame; also have no idea if I'll need to remove the cams or not (hoping NOT too.)

Also hoping to clean the carbs at the same time.

 

[Papa Rocket]

Levi, PM me and I could possibly come by some night & show ya how to take care of the valve adj. (or if I'm a hair slow at the shop, you could bring it by)
I've got an "Ultrsonic" tank for the carbs if ya wanna clean them right.
You wont need the seals as you won't be disassembling the actual valves to do the adjustment. :cheers

 

[Cabanaboy]

Levi, PM me and I could possibly come by some night & show ya how to take care of the valve adj. (or if I'm a hair slow at the shop, you could bring it by)
I've got an "Ultrsonic" tank for the carbs if ya wanna clean them right.
You wont need the seals as you won't be disassembling the actual valves to do the adjustment. :cheers

Thanks alot! I'll probably take you up on the Carb Ultrasonic tank offer, and I'll throw you a PM after this post.

 

[YZFHEFF]

Yes, shim-under-bucket will need the cams removed. Just make sure to get all the caps back on where they came from and keep dirt outta there.

 

[Veefer97]

Get a micrometer from harbor freight to measure the shims. They are not always as thick as they claim. At 30K miles on my 900RR no adjustment needed.

 

[serpentracer]

you can't put valve seals on a valve stem without removing the spring. which requires you to remove the valve keepers and retainer. which will let the valve drop into the engine if you don't support it from below. some guys like to use rope etc stuffing it down the spark plug hole. others use compressed air. they make a fitting specifically for this to hook an air hose to.

personally, if you need valve stem seals because it smokes when you start the engine or the valves have oil on them when it sits overnight, I'd go ahead and remove the head and have new valve guides put in it along with new seats.

 

[enos]

You measure with the cams in, if you need to replace a shim then you need to take the cams off. They usually come out easily.

 

[Veefer97]

How to adjust valves on a shim under bucket system

If you do not know how to get to the cams (under the valve cover) please pay someone to check your valves. This tutorial is generic (Kawasaki zx6 is used as a model) and you should consult your maintenance manual for specific instructions. You also will need some tools, like a digital/dial caliper or better yet a micrometer. Feeler gauges and general tools will also be needed.
Caution: If you perform this task incorrectly engine damage could/will occur. Proceed at your own risk

Tools required for checking valve clearence. Photo also shows valve train assembly but you will not remove valves for clearence adjustment. The bucket and shim are shown in the upper rt hand side of picture.
http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0113.jpg

1 Gain access to cam/ cams and timing end of crankshaft (usually the end away from the alternator side)

2 Rotate crank shaft until the cyl.l # 1&4 align with the alignment mark or pointer. The Kawasaki pictured uses the case split line as a reference pointer. If you are not sure where the pointer is, remove #1 spark plug and place long screwdriver into plug hole. Rotate engine until the piston pushes the screwdriver to the highest level. Do not allow the screwdriver to get jammed in the plug hole. Look at the crankshaft end and the 1&4 marks should be aligned with some feature of the engine such as a pointer.

http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0114.jpg

3 Pistons # 1&4 go travel in unison but 360 degrees out of cam timing phase. What this means is that when the timing marks are aligned only one cylinder is under compression and that is where we want to take the valve clearance measurements. Hint: The cylinder under compression will have the cam lobes pointing at a 45 degree angles.
So place a feeler gauge between the cam and the shim bucket. Use different sizes until a slight drag is felt between the bucket and the cam. Write down the feeler gauge size that was a good fit on all the valves for the cylinder that is being checked.

This is what the cam lobe position should look like before you use a feeler gauge
http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0122.jpg

This picture shows the feeler gauge in use
http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0119.jpg

4 Rotate crankshaft until the pistons # 2&3 mark is lined up. Follow the instructions in step 3.

5 Repeat until all the valve clearances are measured

6 By looking at your measurements and the specifications in the maintenance manual you will be either finished or looking on in this write up. Most bikes require a check and not a full adjustment.

7 In order to adjust the valve clearance the cams may have to be removed.

To remove cams read on

8 Remove the cam chain tensioner and cams. Do not drop timing chain into the engine. Use wire to secure chain. Do not rotate engine with a loose chain as engine damage could occur.

9 After cam removal remove the shim bucket by use of a magnet and remove shim.

http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0111.jpg

10 Measure the shim thickness by use of a micrometer or calipers

11 When you have the shim dimension you can calculate the needed shim. Example: Your valve clearance should be .008”-.012”. Your valve clearance measurement came out to .006”. Your shim thickness dimension is .110” You will need a shim that is at least .002” thinner to meet the minimum valve clearance dimension of .008” So, your shim thickness should be between .104”and 108”. A shim thickness of
.106" would be ideal as it places you in the middle of the acceptable range.

12 Reinstall the cams. Take notice that there is an intake and an exhaust cam. Line up the cam timing marks and check to make sure the crank did not rotate by checking the crank shaft timing marks. The picture shows the cams without the camshaft caps. The intake cam shows chain slack that will be taken up by the CCT after instalation. There shoul be no slack between the exhaust cam sprocket and the crankshaft sprocket after CCT installation

http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0115.jpg

13 Place cam cap cover over cams. Torque cam cap as per manufacturers instructions or you will damage the cam cap. This part is line bored at the factory and if you should damage it you will be buying a new head as the head and the cap cover are sold in pairs only.

http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0116.jpg

14 Before installing the Cam chain tensioner you must first retract the CCT piston by rotating end of tensioner (through the end hole) until the piston is fully retracted. If you fail to do this step engine damage will occur.

This pix shows a fully retracted and fully extended CCT
http://i130.photobucket.com/albums/p269/Fbutaric/DSCF0110.jpg

15 Once the CCT is installed you must release the CCT by turning the CCT piston until it rotates foreward under its own spring tension. Do not force the piston forward after it contacts the chain or engine damage will occur.
Do not rotate crankshaft before releasing the CCT piston or engine damage could occur

16 Double check the timing marks

17 Rotate the engine at least 2 times to make sure the valves do not hit pistons

18 Put all of the removed parts together, leak check valve cover and go for a ride

 

[Saml01]

God damn this is complicated. The tappet adjustment on my 35 year old honda is childs play compared to this.

 

[MT Wallet]

Too hard for me!!! Count me out!!!

 

[Veefer97]

It takes a certain amount of skill but not impossible. You must get it right or bad things will happen.

 

[Veefer97]

you can't put valve seals on a valve stem without removing the spring. which requires you to remove the valve keepers and retainer. which will let the valve drop into the engine if you don't support it from below. some guys like to use rope etc stuffing it down the spark plug hole. others use compressed air. they make a fitting specifically for this to hook an air hose to.

personally, if you need valve stem seals because it smokes when you start the engine or the valves have oil on them when it sits overnight, I'd go ahead and remove the head and have new valve guides put in it along with new seats.

I would do a compression/leak down test before pulling the head which involves pulling the motor from frame. The seals get hard and brittle so the may leak with the rest of the valve train still in good condition.

 

[Cabanaboy]

Wow thanks for all the tips guys and also the write up from Veefer, geesh! I ended up waiting on the Valves basically because I ran out of time and also I'm scared to grenade my top end. I've got a group ride coming up in a few days and then I'm going to try to locate someone who can help me do this proper as I don't want to be 'shooting' in the dark solo.

As for compression; funny thing....I just got done doing that 10 minutes ago! Results:

Plugs are sitting with their respective cylinder on the paper. Each cylinder should be arounf 185 psi, so to me they look great for going on 38k miles of abuse. However, here's the reason why I'm leaning towards new valve seals:

The other 2 are slightly less oily. Ignition area looks a nice tan though. Plus are about 1,000 miles old. Here's a reference of one cleaned with just a paper towel:

What do you guys think? Good cylinder compression but oily plugs.

 

[Veefer97]

The plugs do not look that bad. Seems that the jetting may be a tad rich. Compression is great, nothing wrong there. My 900RR hates the irridium plugs as they get fouled quickly. My recomendation is to use stock plugs

 

[Cabanaboy]

the old plugs looked the same. It's rich because the PO had it rejetted for the K&N and exhaust system, and I rarely get it above 8k RPM so I'm sure that has something to do with it. You can't really see on the paper they are on, but 2 of them actually dripped oil onto the paper underneath. You can see a spot under the Cylinder #2 plug where the oil dripped.

The bike doesn't ever act fouled, and I use to foul out 2-stroke and 4 stroke dirtbikes all the time. She simply rips at all times, maybe a tad boggy under 3k RPM's in a high gear, but that's it.

 

[Veefer97]

The oil may not be from the combustion chamber but from oil traped in the spark plug cavity. Rejet ride and check plugs again

 

[ARozanski]

The gauge worked okay, huh? Good.

Have you been tracking your oil consumption? You could also do a leak down test, will give you a better indicator of the condition of the head and valve train.

 

[Papa Rocket]

the old plugs looked the same. It's rich because the PO had it rejetted for the K&N and exhaust system, and I rarely get it above 8k RPM so I'm sure that has something to do with it. You can't really see on the paper they are on, but 2 of them actually dripped oil onto the paper underneath. You can see a spot under the Cylinder #2 plug where the oil dripped.

The bike doesn't ever act fouled, and I use to foul out 2-stroke and 4 stroke dirtbikes all the time. She simply rips at all times, maybe a tad boggy under 3k RPM's in a high gear, but that's it.

I don't see any oil evidence on the plugs surfaces, just the threads. Possibly a leaking valve cover gasket.
As far as a bog under 3k in high gear... I'd be quite surprised if it did'nt bog at that rpm. :cheers

 

[Cabanaboy]

The gauge worked okay, huh? Good.

Have you been tracking your oil consumption? You could also do a leak down test, will give you a better indicator of the condition of the head and valve train.

Gauge worked fantastic! Thanks a ton for letting me borrow it. I have it cleaned up and ready to return, I got busy yesterday and didn't get it back to you. My schedule 'til Saturday is packed so Maybe Saturday after the ride I can drop it off in person

Oil consumption is negligible at best. I've never had to add any oil to the engine. This last interval was almost 4,000 miles and it didn't even drop on the oil window at all!

I don't see any oil evidence on the plugs surfaces, just the threads. Possibly a leaking valve cover gasket.
As far as a bog under 3k in high gear... I'd be quite surprised if it did'nt bog at that rpm. :cheers

Haha, ya the oil is only on the threads, ignition area looks fine. Same with the original plugs as well. Burned a healthy light tan. By bog I don't mean the typical fall on it's face, it's more like it is way out of it's area of power. Picks up at 5k RPM's then screams from 8k RPM's til 12k :banana

 

[Veefer97]

Try dropping the needles one shim (half a clip). That will lean out the midrange