First time valve check on 749.. need advice. - Ducati.ms

rubber duckie · Feb 3rd, 2012, 6:47 pm

well im thinking of diving in and tackling my first valve check on my 749, but i have a couple of small questions.

what kind of silicone do i use with the gasket to seal the valve cover? as it sits now my valve cover is leaking.

what kind of assembly grease do i use when installing cams.

and any other tips and tricks you vets have for a noobie. thanks.

smokey999 · Feb 3rd, 2012, 7:36 pm

Hey dude!

Congrats on wanting to do this on your own. Its a very time consuming and frustrating experience the first time. Okay, at least for me it was. But then again i tend to be way too picky about my motorcycles.

As far as your questions:

I use the grey RTV silicone because A: it matches the castings pretty well and B: it Doesn't leak.

Also when you remove your cams to do the valve check there is no need for an assembly lube. The assembly lube is for brand new cams going into brand new bearings to help seat and "mate" the surfaces. On your bike, these surfaces are already mated so need no oil other than making sure that everything is very very clean and free of dust and debris. As far as checking the clearances are concerned the only tip i have is make sure you have your cams in the closed position and check them a clyinder at a time. Also don't be afraid if there is one or more (or all) valves read within nominal. Make sure to have a good shim kit on hand. If your having to shave a shim down. Use 500 grit sand paper with a little oil. And use circular motions when sanding on the shim. Remember your working in less that .0005 of an in so take your time and get it right the first time. After you got your lash looking good. set your belt tension and put your valve covers on with a very light and i mean very light bead of silicone around the whole thing (I hate oil leaks) and bolt her back together. Another thing is move everything out of the way that you feel you need. Don't be afraid. You'll have a better time and not dread it the next time. Also take this time to clean your engine with some purple power and check out everything. This is something i do at my speed shop whenever i get a bike on my lift. If you would like a more detailed way of going about it, message me and ill send it to you.

pjonte · Feb 3rd, 2012, 8:31 pm

Not trying to bash but smokey999 sounds clueless. You don't need to pull the cams to check valve clearances, just the valve covers. Get a workshop manual, it will explain how to strip everything down to the cams. Don't just use "Grey" RTV because it "matches" - get a tube of three-bond or equivalent engine rated sealant. Figure on replacing the belts while you are at it, cant accurately check the valve clearances with the belts on. Look on YouTube for video on changing belts on a 749, if after watching it you don't feel comfortable with the work up to that point STOP and take it to your dealer. If you decide to press on then "checking" the clearances after the belts are removed is pretty straight forward. If after you've checked the clearances and find one or more needing shimming then things get a bit more complicated, and you will need to pull the cams. This will require a few special tools and a shim kit with various shim thicknesses. You'll also need a good micrometer that will measure in tenths of thousands - if all this sounds Greek consider having the valves shimmed professionally.

2c

rubber duckie · Feb 3rd, 2012, 9:43 pm

Quote:

Originally Posted by pjonte

Not trying to bash but smokey999 sounds clueless. You don't need to pull the cams to check valve clearances, just the valve covers.

2c

in his defense i believe he means if i need to change the shims then the cams come out.

thanks guys, these were everything i already learned. where can i find that 3bond?

i also read that some of you guys use yamaha and honda sealers too.

rubber duckie · Feb 3rd, 2012, 9:45 pm

Quote:

Originally Posted by smokey999

Hey dude!

Another thing is move everything out of the way that you feel you need. Don't be afraid. You'll have a better time and not dread it the next time. Also take this time to clean your engine with some purple power and check out everything.

everything is almost off already. bought new silicon hoses too to replace the old ones that look like they leak a tiny bit of coolant. and i do plan on degreasing the engine when valves are checked before everything goes back in.

Thack · Feb 3rd, 2012, 11:36 pm

I try to have at least .002" clearance on the intake and .004" on the exhaust for the openers. Do not sand or grind valve shims! They are only $8.00 from Ducati Omaha.
Engine oil is fine to cover the cams upon installation. Just so they are not "dry" at start up.
Yamabond, Kawibond and Threebond are really similar. Permatex MotoSeal may be a good alternative too.

Turboflyer · Feb 4th, 2012, 12:46 am

I would still use assembly lube. Once the cams are out, if you need to remove them, the oil runs pretty much away from and out of the cams. Clean is not good enough. And it does not help things break in, it keeps metal to metal contact from happening. Agree on the belts, 3 bond/ yamma bond,. You will be hard pressed not to have to hone if you want it right. Maybe it happens. Never has for me. As far as .002 and .004 I know even LT says he does it, but that is just to close on the closers for me. Do some fact finding first. I like closer at .004 and openers at .006, but to each his own. Take it all and remember it is your bike. What ever you do don't get in a hurry and keep accurate notes and thing organized. BTW sharpie mark your cam caps and even the cams, just saves the oh I will remember then the humm I think I........Good luck on the job for sure.

rubber duckie · Feb 4th, 2012, 1:38 am

now im confused.. im reading through the workshop manual and it hits me..

i was taught the loaded unloaded method. how does this differ from the workshop manuals check "between the opening rocker arm and the lower edge of
the camshaft cam." and "between the closing rocker arm shoe and the upper
edge of the camshaft cam"

how do i calculate which shims are needed?

Turboflyer · Feb 4th, 2012, 10:16 am

I don't think you are alone on the confusion. I had the same what the hell are they talking about problem. What I found was on the testra engine you have access to the cam and do not measure the same way. Still even in LTs book he shows a loaded and unloaded work sheet. Go figure. The math is pretty straight forward though with out that. Hope that helps.

Thack · Feb 4th, 2012, 11:56 am

Start here and measure your clearances...

Ducati 4 valve adjustment Part I - YouTube

then post your clearances and we will go from there.