Tappet adjustment???

[Chuck]

I am adjusting the valves for the first time on my 66 Monza. It says in the book to set the tappet clearance to .3mm, is that for both intake and exhaust? The previous owner has the intake at .3mm but I can't find any clearance for the exhaust side. Are both intake and exhaust clearances adjusted at TDC on the compression stoke when both valves are closed?

Chuck

[DewCatTea-Bob]

" It says in the book to set the tappet clearance to .3mm, "

____ What "book" is that ? - A late-70s edition by Clymer ?
Cuz .3mm is nearly 12-thouthandths and the adjustable-type screw-adjuster/rocker-arms (within Monza-models) are supposed to be set at .002" (intake) & .003" (exhaust) ! _ (That's same as .05mm & .076mm !)


" The previous owner has the intake at .3mm but I can't find any clearance for the exhaust side. "
____ First,, that's too-great of a gap (by about 4 to 6 times), for standard Monza-rockers ! _ And second, do you mean your "book" doesn't offer a clearance-setting for the ex.side, OR, do you mean you can't measure ANY amount of clearance at all (between the rocker-tappet & the ex.valve) ??


" Are both intake and exhaust clearances adjusted at TDC on the compression stoke when both valves are closed? "

____ Yes, that's correct !
So when at compression-TDC, there should be 2 to 3 thousandths clearance found between the tip-end of the valve-stem & the flat of the ball (in the screw-adjuster).


____ BTW, how/why did you post this new thread of yours TWICE ?


Duke-Cheers,
-Bob

[Chuck]

Thanks for your help. The book I am working from is "Ducati -- Over Head Camshaft Motorcycles Works Shop Manual". It says it is a first edition (1966) but I was told it is Domi Racer reprint. The book is very good condition and has the fold-out page with the motor schematic. I also have a Clymer Ducati 160-450 Singles and another Ducati Workshop Manual by Tom Bailey. All the books are the same so I am using the old book.

I think I got confused reading under "Check the timing" #4 on page 89 to set the tappets to 0.3mm and when I checked the bike thats where the previous owner had the intake valve set. The exhaust value had no clearance. On the next page is the "clearance" that has the correct setting so I guess I should read the whole section before do anything.

I adjusted the valves this morning and everything went fine. The only problem I had was with the valve covers, getting the 5mm Allen screw out from the bottom locations, I am going to look for a round head Allen key to make the job easier.

I also set the ignition gap to the prescribed clearance, it was at about 1/2 of what it should be, it was about .006.

I'm now up to setting the ignition advance. I'm not sure how to check the automatic advance mechanism so I think I'll just leave it alone. I got the inspection plug out and looked inside and see a threaded whole that I can put a bolt into to connect a degree wheel, do you know threading and size the bolt is?

I have only gone around the block a few time but I could hear the valves making a lot of noise so I hope I solved that problem. The motor is also kicking back when I start it and I hope that adjust the points clearance will help. I can't figure out in my head, if with the points clearance being to close, if that would advance or retard the timing when starting the motor up. I know very well from my Velocette's that if the magneto timing is not retarded enough it will kick back when starting. Maybe this has been solved.

I was able to get the selector box and gears to work after I realized the spring was in wrong.

One of the problems I am having it that the previous owner, or owners, were terrible mechanics and butchered many of the screw heads. When I adjusted the points I had to fight hard to get the screws out and I had to dress them up with a file to reuse. Do you know where I can buy small metric screws like the ones inside and outside the points cover?

I don't know why my thread was sent twice?

Thanks,

Chuck

[DewCatTea-Bob]

" so I am using the old book. "

____ The old orange book is the most trustworthy !


" I think I got confused reading under "Check the timing" #4 on page 89 to set the tappets to 0.3mm and when I checked the bike thats where the previous owner had the intake valve set. "

____ That is a very COMMON mistake ! _ Even the newer Clymer workshop-manuals have confused the factory-ecommended working valve-clearances with the clearance-settings meant only for checking the valve-timing of the various camshaft models !


" I also set the ignition gap to the prescribed clearance, it was at about 1/2 of what it should be, it was about .006. "

____ That was indeed too small !
Always shoot for .016 to .018" .


" I got the inspection plug out and looked inside and see a threaded whole that I can put a bolt into to connect a degree wheel, do you know threading and size the bolt is? "

____ That threaded-hole in the end of the crankshaft will accept a 8x1.25mm bolt.


" I could hear the valves making a lot of noise so I hope I solved that problem. "

____ Reducing the valve-clearance about the 9-thousandths which you did, will certainly help !


" The motor is also kicking back when I start it and I hope that adjust the points clearance will help. "

____ Well unfortunately that which you've changed will likely make it worse, cuz opening-up the points-gap will have further advanced the ign.timing.


" if with the points clearance being to close, if that would advance or retard the timing "

____ With the points-gap being too close, that would tend to RETARD the ign.timing.


" Maybe this has been solved. "

____ No, not at all likely ! _ Cuz you opened-up the gap, so you thus-then ADVANCED your ign.timing (from where-ever it was set-at before) !
__ When the static-timing is properly set to 5-degrees BTDC, then kick-back should not be much of an issue.


" Do you know where I can buy small metric screws like the ones inside and outside the points cover? "

____ These-days most-all good hardware-stores stock such common metric-screws. _ So take one of yours to your local hardware-store and have them match it as well as possible.


" I don't know why my thread was sent twice? "

____ I've never seen that happen before ! _ I'll delete the extra/untouched one.


Hopeful-Cheers,
-Bob

[DanM]

In the TECH area of Motoscrubs there is a lot of good information. Here's the link to timing a Ducati single:

http://www.liebold.com/timing/timing.htm

[DewCatTea-Bob]

" In the TECH area of Motoscrubs there is a lot of good information. "

____ I really hate to stretch my-own credibility but, that section has some WRONG things to be found within,, so I wouldn't say it's ALL "good" .
__ I suggest double-checking anything of real importance against other sources, and if they don't completely agree, then try asking me which I believe is actually correct.


Dukaddy-DUKEs,
-Bob

[averydad]

Setting my tappet clearance today I checked three books that I have collected. First is a 1964 factory owners manual, second is a 1966 orange cover shop manual published by Clymer and the third is a 1974 Clymer manual covering all Ducati singles up to 450.
It`s amazing that there is so much conflicting and WRONG information out there !
I had seen this thread and upon reading, I see that Bob agrees with the factory owners manual ( Instructions for use and Maintenance ) .0020" to .0028". I trust Bob and also must think the original hand book would be most accurate.
20 to 30 thou is the spec for my Honda CB400 four tappets as well so that makes sense to me.

Here are the books in question.
Rick

[DewCatTea-Bob]

" I see that Bob agrees with the factory owners manual ( Instructions for use and Maintenance ) .0020" to .0028". I trust Bob and also must think the original hand book would be most accurate. "
____ I agree with those manual/books because I trust the publications put-out by Ducati-themselves.
__ All the book/pages you have posted state factory-figures, it's just that when Clymer updated their publication to include WideCase-models, they hastily copied-over their own information and mistakenly labeled some of it incorrectly...
So in the case of WORKING valve-clearances, they copied the list of factory clearance-figures used for checking the valve-timing (of various camshaft-models), and mistakenly labeled that list as if for recommended/normal valve/rocker-clearance.


" 20 to 30 thou is the spec for my Honda CB400 four tappets as well so that makes sense to me. "

____ Instead of "20 to 30 thou" (which is same as .020" to .030" !), you must have really meant just '2 to 3 thousandths' -(.002 to .003"),, cuz YOUR stated-figures would indicate TEN-times greater clearance-space ! _ (And surely Honda would not recommend that.)


Dukaddy-DUKEs,
-Bob

[averydad]

Yes...of course I mis stated the decimal. 2 to 3 thousandths is where I set my clearance on the Monza.
I posted the books and pages to caution other novice owners like me as to the conflicting info.

If not for this forum I may have gotten it VERY wrong.