Who can give me a nice easy clear explanation of a valve adjustment;

How its done
Why it must be done
The cost of doing this via bike shop
Consequences of not adjusting them

My bike has 44k miles and it hasnt been done
-Thanks

And which adjustment are you referring to?
There's a few on this bike.

Adjustment of what? Valves?

I will admit, my bike has 24,000 on it and I have not checked my valve clearances yet either. I will definatly tackle this after Christmas. I've read a few reports of people whose valves needed no adjustment, or very minimal, at the first 16K mile checkpoint. My bike has been running so well, I wasn't to worried about it.

With 44K, I would be doing it asap. btw, a shop will charge upwards of $400. I think the Honda service writer told me the book calls for a minimum of 5 hrs. labor. Maybe more if valves need shimming. Not positive on that, going of memory from about 9 months ago.

If you don't already have a shop manual, here's a free download that a lot of us use.
It take's a few minutes to download, it's a big file. Use this one:

•US VERSION RC51 Factory Service Manual SP-1 and SP-2 108.2 Mb
http://www.rc51.info/index.php?page=service

And which adjustment are you referring to?
There's a few on this bike.

Sorry, I thought I specified.
Fixed my error.

Valve Adjustments

Adjustment of what? Valves?

I will admit, my bike has 24,000 on it and I have not checked my valve clearances yet either. I will definatly tackle this after Christmas. I've read a few reports of people whose valves needed no adjustment, or very minimal, at the first 16K mile checkpoint. My bike has been running so well, I wasn't to worried about it.

With 44K, I would be doing it asap. btw, a shop will charge upwards of $400. I think the Honda service writer told me the book calls for a minimum of 5 hrs. labor. Maybe more if valves need shimming. Not positive on that, going of memory from about 9 months ago.

If you don't already have a shop manual, here's a free download that a lot of us use.
It take's a few minutes to download, it's a big file. Use this one:

•US VERSION RC51 Factory Service Manual SP-1 and SP-2 108.2 Mb
http://www.rc51.info/index.php?page=service

Dam...
My brother gave me his 2002 Rc51 after putting 44k miles on it
and now I gotta fix it up to make it run perfectly well again.


Im going to take it to the shop today to get a 50k mile diagnostics
and also figure out why my bike wont start.

All I've changed since I got the bike was;
air filters, spark plugs, oil/filter, fork seals, tires, wheel bearings, brakes/fluids.

Dam...
My brother gave me his 2002 Rc51 after putting 44k miles on it
and now I gotta fix it up to make it run perfectly well again.


Im going to take it to the shop today to get a 50k mile diagnostics
and also figure out why my bike wont start.

All I've changed since I got the bike was;
air filters, spark plugs, oil/filter, fork seals, tires, wheel bearings, brakes/fluids.

"Dam..." is right! gave? As in free? 'Tis the season! Welcome, and what a nice bike to have given from an obviously cool brother.
I think you are going a good route, having trained techs examine a bike that's new to you. As long as your shop is a reputable one, that is.
Btw, good job on all the stuff you've already changed. I see about $500-600 there plus all the labor. Obviously you're serious about one of the finest superbikes on the road. Good Luck!

Who can give me a nice easy clear explanation of a valve adjustment;

How its done
Why it must be done
The cost of doing this via bike shop
Consequences of not adjusting them

My bike has 44k miles and it hasnt been done
-Thanks

Valve clearances can change over time due to valve seat wear, metal creep, etc.
Valve clearances can get tight or loose depending on the circumstances.
The effect of incorrect valve tolerances can vary depending on the amount.
Minimally, changing valve clearances can alter intake or exhaust timing and duration slightly.
To a greater degree, too tight a clearance can prevent proper valve seating and loss of compression, and possible burnt exhaust valves due to to combustion gases passing past the valve head during ignition phase.
Too loose a clearance and damage to the cam lobe and bucket can result.

The valves are actuated by an overhead cam actuating a bucket tappet.
A shim is placed between the valve stem and the underside of the bucket to adjust clearance.
A measurement is made of the clearance between the cam lobe heel and the bucket face with the cam at it's specified alignment mark.
Each shim has a marking indicating it's thickness in millimeters.
A calculation is done to determine the next thinner or thicker shim required to correct the difference.

To replace the shims, the engine is rotated to a cylinders timing marks with both cams lobs up and cams timing marks level with the cylinder head.
The cam mount caps are removed, the cams removed and the shims swapped.
The the cams installed aligned with timing marks, then the cam mount caps installed and torqued.
The clearances are rechecked and if ok, proceed to the next cylinder.

All this is done according to the service manual procedures.
One very important thing to note is, the cam mount caps have arrows and mark indicating exhaust or intake cam, and both point to the intake side of the engine. Do not mix the caps or journal damage will result.

It's also best to start with the front cylinder since it's only a 270 degree (3/4 turn) rotation to the rear cylinder.

The cost can vary depending on which shop does the work.
I do my own, so time and labor don't count.

The valves should be checked every 16,000 miles.
Often they don't need re-shimming, but at 44,000 miles I suggest you do check the clearances.

Im at 16,1xx on the odo, im going to check mine just because the book says so, while the skins and tank are at the paint shop.

Sub,
I always love reading your "how to" posts, always more info then whats needed to do the job.
Between you and some of the other members makes this forum one of the best assets to have.
Thanks again
James

Im at 16,1xx on the odo, im going to check mine just because the book says so, while the skins and tank are at the paint shop.

Sub,
I always love reading your "how to" posts, always more info then whats needed to do the job.
Between you and some of the other members makes this forum one of the best assets to have.
Thanks again
James

Isn't that the truth. I have a folder in my Favorites that I link to those kinds of posts from SubSailor. Hats off to our best Moderator who really knows his sH$t about these RC51's :) :)

So Sub, When a valve is not being actuated by the cam lobe the cam and bucket do not contact, there is a gap between the cam and the bucket and that is the clearance in question? I am used to automotive engines that use hydraulic adjusters.

"Dam..." is right! gave? As in free? 'Tis the season! Welcome, and what a nice bike to have given from an obviously cool brother.
I think you are going a good route, having trained techs examine a bike that's new to you. As long as your shop is a reputable one, that is.
Btw, good job on all the stuff you've already changed. I see about $500-600 there plus all the labor. Obviously you're serious about one of the finest superbikes on the road. Good Luck!

Yes "gave", as in free!
I've been putting a lot of money into this bike and i want it to be 100%
So i can ride in the summer of 2012.

I took it to the shop and went back after they checked my starting problem/any other problems i need to fix.
Turns out I had bad luck with batteries. Anyways, the only neccessary changes that need to be made are Valve Adjustments, brake/clut h fluids, drain coolant, and to replace the sprocket/chain.

After that Im aiming to get a new right & left OEM panel, Solo Seat cowl and a LED Undertail

So Sub, When a valve is not being actuated by the cam lobe the cam and bucket do not contact, there is a gap between the cam and the bucket and that is the clearance in question? I am used to automotive engines that use hydraulic adjusters.

That is correct. During the valve adjustment, you are measuring the gap or clearance between the face of the bucket tappet and the heel of the cam.
During operation there is of course an oil film on both faces, but the film is very small.

This method of valve actuation has been in race use for decades.
A variation of this was pneumatic valve springs in F1 in the 90's which kept the bucket tappets, but substituted coil springs for highly compressed air and seals in the tappet bore. It allowed higher RPMs beyond 18K RPM, which is the limit for coil springs.

Current F1 engines no longer use bucket tappets, but use finger followers that press on the valve stem and actuated by an overhead cam.
The BWM S1000RR and the Buell 1125/1190 engine use this method also.

On F1 engines, it serves two purposes.
1) The valve train has less mass, so higher revs can be used.
2) More importantly, it allows a narrower included valve angle and so a flatter combustion chamber and piston can be used, which allows efficient combustion.

Here's something to watch :)

http://www.youtube.com/watch?feature=player_detailpage&v=nt54qL29wBo

Not too bad as an overview, but he doesn't even mention the cam timing marks, which are critical.
Also the cam journal caps have marks indicating direction and which cam they go to.

Here's a photo of the rear cylinder showing the cams at their alignment position to check valve clearances.

http://i407.photobucket.com/albums/pp158/rc51/rearcylindercamsandjournals.jpg

This is a closeup of the previous photo.
Of special note is the orientation and position of the cam journal caps.
Not only do they always point towards the intake side of the engine (front journal caps as well), but each cap has marks indicating it's position.

The marks that are not scribed through indicate it's position.
This is very important because the caps are installed and torqued, and the line bored during manufacture. If the caps are mis-installed, damage can occur to the caps, cylinder head, and cam journals.

http://i407.photobucket.com/albums/pp158/rc51/rearcamshaftsandjournalcaps.jpg

That is great stuff SubSailor. You just made it more feasible for me to do this project too. Thanks for your detailed description and great pictures.

I had my valves adjusted at around the 24-25k mile mark and only one shim needed changing. Luckily one of the techs here did it for me on one of his off days for a really fair price. IIRC, it took around 4-5 hours from start to finish. Our shop charges like $93 an hour so you can figure the labor from that. By all accounts, I've heard the job itself isn't that difficult so long as you have the right tools.. it's just time consuming is all.

I had my valves adjusted at around the 24-25k mile mark and only one shim needed changing. Luckily one of the techs here did it for me on one of his off days for a really fair price. IIRC, it took around 4-5 hours from start to finish. Our shop charges like $93 an hour so you can figure the labor from that. By all accounts, I've heard the job itself isn't that difficult so long as you have the right tools.. it's just time consuming is all.

The rear cylinder is a piece of cake if you have the fuel tank off (as the photo shows). It's pretty snug with the tank on.

The front cylinder is more difficult with the suspension in the way, and the left radiator makes it difficult to poke your head in to check the timing marks.
Plus, on the SP1 you have to drop the oil cooler down, and on the SP2 it's the air guide plate, which is a lot easier.

The front valve cover is also a bit difficult to remove because of the radiator hose that crosses directly over the raised valve cover area where the breather hose is attached.

Also for the front cylinder, it's also very important to ensure your bike is clean of any dirt or debris that may fall into the valve area once the cover is removed. I'd wash the bike in that area and let it dry before the operation.

Here is a better explained video of how to do a valve check/adjustment

http://www.youtube.com/watch?v=X8hvVyzE2xY&context=C3907ae8ADOEgsToPDskJRwz4qbZ_l-7bmr13FfNGO

Here is a better explained video of how to do a valve check/adjustment



Great video, makes it look easy!