Valve Adjustment

[Nemesis]

Search?

[Bones85]

Originally Posted by Nemesis

No way in hell I'd ever attempt to do this again. I broke the cam lobes (trying to put it back in place).

I'll pay and have paid a mechanic to do this for me.

I think I'll do a few more weeks of research before attempting this on my own

[Bigballsofpaint]

Nemesis, the last valve change i did (my first, not my bike ) the same thing happened to us with the cam. We didnt remove the tensioner first and cracked that little piece off. I talked to a lot of people and we decided to just grind it smooth, took all the burrs off so it wouldnt catch on anything and then popped it back it. Bike is still running fine...I finished my valve adjustment last night finally.

[Nemesis]

Do a search and you'll find pics of the broken cam. The cams lobes or whatever you call it that sits into the groove are a lot softer than you think.

[Bigballsofpaint]

i did search, and i pulled up your thread when it happened to us. Like i said, we did the same exact thing on the last valve adjustment. There was another thread or 2 on it, thats what happened if you loosen the caps up before taking the tensioner off. If you notice its the intake side that busts, since thats the side with all the tension on it.

[Nemesis]

All I know is I ain't touching that shiet eva again. LOL

[249cc]

Can't believe I'm going to ask but...Alex, mind helping me do my valves?!

[rojoracing53]

Originally Posted by 249cc

Can't believe I'm going to ask but...Alex, mind helping me do my valves?!

This can only end with your motor grenading in a most spectacular fashion

[Bones85]

Already ran into a problem. When I remove the hoses from the gas tank, fuel keeps leaking from the petcock. I followed this tutorial: http://www.ninjette.org/forums/showthread.php?t=10191

Fuel tap is in the "ON" position like the tutorial states.

[Bigballsofpaint]

bad petcock, debris in petcock, etc. theres a few threads on this issue, my bike had the same problem when i just did my valves.

[Bones85]

Are you sure it's a bad petcock? Does it matter which order the hoses are disconnected?

I don't want to spend another $100 for a new part. I've never had any problems with the petcock leaking besides this time when I took the tank off for the first time.

[fishdip]

Originally Posted by Bones85

Are you sure it's a bad petcock? Does it matter which order the hoses are disconnected?

I don't want to spend another $100 for a new part. I've never had any problems with the petcock leaking besides this time when I took the tank off for the first time.

yes its the petcock mine did the same. I fig mine for some time by putting a aftermarket fuel filter on the gas was not able to drip past it.

[Bones85]

I'm starting to regret buying this bike and now I probably won't be able to ride for a week or two.

Should I take the petcock apart and try to repair it first?

[Bigballsofpaint]

i didnt bother fixing mine, it reallyb ecomes an issue if your carbs arent too great.

[Bones85]

Did you just drain the gas tank then?

[Bigballsofpaint]

ya i drained it into a gas can i had, poured the gas back into the tank when i put it all back together

[Bones85]

I have everything lined up at 2T like the tutorial states. White marks are all lined up just like in the picture. At this point I should measure the four right cylinder valves? I noticed the buckets for the right cylinder are recessed while the buckets for the left cylinder are still up. Am I supposed to measure the clearance when the buckets are recessed?

[Bones85]

Or should I measure the valves on the first cylinder at 1T and then go to 2T? Also, which valves are the exhaust and which are the intake? I know there are two intake and two exhaust per cylinder but which ones are which?

[Motofool]

Originally Posted by Bones85

Or should I measure the valves on the first cylinder at 1T and then go to 2T? Also, which valves are the exhaust and which are the intake? I know there are two intake and two exhaust per cylinder but which ones are which?

Yes, Joe, cylinder #1 is the one on the left side of the rider's position and #2 the one on the right.

They stroke in an alternative way, so, one #1 is at Top Dead Center (TDC), #2 is at Bottom Dead Center (BDC).

Intake valves are the ones closer to the carbs and exhaust valves are the ones forward.

The gaps are measured when the cams are not pushing the valves down.

I recommend you following this step-by-step:

http://www.theyeagergroup.com/2008_n..._clearance.htm

[KawiKid860]

Shim under bucket valves suck. Currently doing this on my CBR, what a PITA. Screw and locknut is the best thing ever made, takes me 2 hours on my 500 if I take my time

[Bones85]

Originally Posted by Motofool

Yes, Joe, cylinder #1 is the one on the left side of the rider's position and #2 the one on the right.

They stroke in an alternative way, so, one #1 is at Top Dead Center (TDC), #2 is at Bottom Dead Center (BDC).

Intake valves are the ones closer to the carbs and exhaust valves are the ones forward.

The gaps are measured when the cams are not pushing the valves down.

I recommend you following this step-by-step:

http://www.theyeagergroup.com/2008_n..._clearance.htm

I've read that guide. When looking at the crankshaft from the left side of the bike (clutch side), cylinder #1 is on the left and cylinder #2 is on the right, correct? If it's at 2T and I'm supposed to measure cylinder #2 (cylinder on the right) then why is the bucket pushed down?

[Motofool]

Originally Posted by Bones85

......When looking at the crankshaft from the left side of the bike (clutch side)....

Clutch is on the right side of the engine.

The camshaft turns once for every two turns of the crankshaft.

You may be seeing the one that does not correspond to the TDC when both pairs (intake and exhaust) of valves are closed (there is gap between the four cams and valves of that cylinder).

Never turn the crankshaft clockwise !!!

[Bones85]

Originally Posted by Motofool

Clutch is on the right side of the engine.

The camshaft turns once for every two turns of the crankshaft.

You may be seeing the one that does not correspond to the TDC when both pairs (intake and exhaust) of valves are closed (there is gap between the four cams and valves of that cylinder).

Never turn the crankshaft clockwise !!!

So even though it looks exactly like this in the picture:

It's not the correct way if the right cylinder buckets are recessed?

[Bigballsofpaint]

it doesnt matter where the crankshaft is when your checking the valves. Just make sure the cams arent contacting the buckets when your measuring them. IF you need to make adjustments, make sure you put it to 2T BEFORE you start taking things apart. I always mark the cam chain and sprockets too just to make sure it all goes back together the same way.

[Bones85]

I found this video: http://youtu.be/Owd-cg92bTQ

At 0:13 he says you can't check the exhaust valves without taking that cover off. In both tutorials I read, they never mentioned removing that cover.

[Bones85]

Originally Posted by Bigballsofpaint

it doesnt matter where the crankshaft is when your checking the valves. Just make sure the cams arent contacting the buckets when your measuring them. IF you need to make adjustments, make sure you put it to 2T BEFORE you start taking things apart. I always mark the cam chain and sprockets too just to make sure it all goes back together the same way.

Service manual says:

Each piston has two inlet and two exhaust valves. Measure
these two inlet or exhaust valves at the same crankshaft
position.

Valve Clearance Measuring Position
#1 Piston TDC at End of Compression Stroke:
Inlet Valve Clearances of #1 Piston
Exhaust Valve Clearances of #1 Piston

NOTE

○Check the valve clearance using this method only.
Checking the clearance at any other cam position may
result in improper valve clearance.

Valve Clearance Measuring Position
#2 Piston TDC at End of Compression Stroke:
Inlet Valve Clearances of #2 Piston
Exhaust Valve Clearances of #2 Piston

[Motofool]

Originally Posted by Bones85

So even though it looks exactly like this in the picture: .........
It's not the correct way if the right cylinder buckets are recessed?

I cannot see the position of the cams in that picture.

The 2T mark means that the piston #2 is at the top dead position, position at which the four valves of that piston should be perfectly closed.

There are two TDCs': one between exhaust and intake strokes and another between compression and work strokes.

http://www.animatedengines.com/otto.html

The timing for the valves (for the pre-gens) is as follows:

Inlet valves open at 30 degrees before Top Dead Center

Inlet valves close at 70 degrees after Bottom Dead Center

Exhaust valves open at 70 degrees before Bottom Dead Center

Exhaust valves close at 30 degrees after Top Dead Center

All valves are open during 280 degrees in a symmetrical way.

Link to original page on YouTube.

The only reason to be for the gap that you are measuring is for accounting for the longitudinal dilatation of the valves, which will make the buckets barely "kiss" the round portion of the cams when the engine is working at normal temperature.

A bigger than specified gap means excessive noise and late opening-closing.
A smaller than specified gap means that valves will not close completely and will leak, reducing compression and getting burned (exhaust valves).

[Bones85]

[Motofool]

Originally Posted by Motofool

...........Intake valves are the ones closer to the carbs and exhaust valves are the ones forward..........

How can cylinder #1 work properly having four exhaust valves?

How can cylinder #2 work properly having four intake valves?

[Bigballsofpaint]

Bones, just take a second and really think about what your doing. The intake valves are the ones on the side where your intake (carb boots) are. The exhaust valves are ont he side where the exhaust comes off the motor. Looking at your picture you are thinking the wrong thing. The 4 valves on the bottom are all exhaust, the 4 on the top are all intake.

As for measuring the valves, yes i know what the manual says, and yes you can definitely do it that way. But i just dont feel like getting my flashlight and looking to make sure its exactly at 2T or not. You just want to make sure the cam in not touching the bucket, You can visually see it as you turn the motor

[Bones85]

That's why I was so confused then

I thought the two cylinders had a gap between them with each having four valves in a row

[Bones85]

I finished measuring all 8 valves. The results are not surprising considering the bike has almost 12,000 miles and the valves have never been adjusted.

Valve Clearance

Standard:
Exhaust 0.22 ∼ 0.29 mm
Intake 0.15 ∼ 0.24 mm

EXHAUST (mm)
1 0.15 OUT
2 0.15 OUT
3 0.16 OUT
4 0.18 OUT

INTAKE (mm)
1 0.23 IN
2 0.22 IN
3 0.20 IN
4 0.18 IN

What would you all recommend adjusting the valves to? Should I adjust them to the middle (exhaust valves to 0.25mm) or should I adjust them on the looser side (i.e. exhaust valves at 0.27-0.29mm) because the valves get tighter over time.

[Motofool]

I would leave the intake valves as they are now, and would increase the gap for all the exhaust valves to be close to max (0.27~0.29).

[Bones85]

I was thinking of adjusting intake 3 and 4 because they might go out of spec soon or should I just leave them for now and check the valves again in 7,500 miles?

[Bones85]

.

[Motofool]

Originally Posted by Bones85

I was thinking of adjusting intake 3 and 4 because they might go out of spec soon or should I just leave them for now and check the valves again in 7,500 miles?

That is a good idea.
As you can see, the exhaust valve tend to reduce the gap faster than the intake (cooler gases go thru).