Monza timing??

[Chuck]

I tried setting the timing on my Monza but there is a problem. I followed all the instructions in the books and also checked that the automatic advance unit - the weights move out and turn the cam. The test lights goes out at about 20-21° before TDC so I went to retard the points plate but it was already set at fully retarded by the previous owner. I though about machining the backing plate but that does not seem like an elegant solution. Is there something I am missing or does anyone know what I should do next?

[wcorey]

And that 20-21 degrees is with the AAU fully advanced?


Bill

[Chuck]

The 20-21° is with the pints in the static position, the weights are in the center, so I think it is fully retarded for starting?

[DewCatTea-Bob]

" with the pints in the static position, the weights are in the center, so I think it is fully retarded for starting? "

____ That's of-course as everything should be.
__ Are you sure you have a "Monza" and not a Scrambler model ?
____ Anyhow, perhaps somebody in the past had the front-right engine-cover off and then didn't reinstall the ign.points drive-gear back-in properly timed ?
If you're sure you haven't errored somehow, then you'll probably have to remove that engine-cover and correctly reset all the timing-dots on all the involved gears.


Hopeful-Cheers,
-Bob

[Chuck]

The motor number is DM 250 92748

I was afraid that checking the timing gears would be the next thing to do. I will go through the timing procedure again but I'm sure I will come up with the same readings especially since the bike came to me with the points set at full retard and the overall timing still being advanced. Maybe the points were set at 1/2 the correct value to help retard the motor?

I've looked at the Workshop manuel and Mick Walker's Restoration book and I think I have some idea of what to do.

Do I need a new gasket when I put the timing cover back on or can I use the old one if it is not ruined when I remove the cover?

Do all the timing dot line up with the piston at TDC on the firing stroke?

If the timing gear is out of sync how do I make it correct? The Mick Walker book has a picture of the timing cover coming off with the points gear in the cover but the motor illustration has the gear in the motor. Will the gear come off with the cover like the picture shows? If it does how do I know if it was in the correct timing spot? Is it as simple as just moving the points gear one tooth to get it in sync? Are there any "surprises" I should know about before removing the cover? What do I do next if the timing is correct?

[DewCatTea-Bob]

" Maybe the points were set at 1/2 the correct value to help retard the motor? "

____ That may be true,, if all else is correct, then it seems to me that somebody may've replaced the stock points/timing-plate with a plate from a Scrambler-engine, (as it's adjustment-slots are not as wide).



" Do I need a new gasket when I put the timing cover back on or can I use the old one if it is not ruined when I remove the cover? "

____ If it doesn't get too torn-up, I'd usually retain it and also add a smidgen of 'silicone-seal' smeared over it.



" Do all the timing dot line up with the piston at TDC on the firing stroke? "

____ Yes, that's supposed to be correct.



" If the timing gear is out of sync how do I make it correct? "

____ With the removable connecting gear pulled-out of place, rotate the others and reassemble them all back together... you'll see what needs to be done with minimal trial-&-error.



" The Mick Walker book has a picture of the timing cover coming off with the points gear in the cover but the motor illustration has the gear in the motor. Will the gear come off with the cover like the picture shows?
If it does how do I know if it was in the correct timing spot? "

____ Yes it will unless you take steps to keep that gear in it's normal place.
If you wish to check it's current timing-location, then you have to pull-out/off the AAU and then keep that gear pushed back in place while pulling-off the engine-cover.



" Is it as simple as just moving the points gear one tooth to get it in sync? "

____ Yes...
Rotate that gear 1-tooth counterclockwise from where-ever it's currently timed at.
Hopefully, that change will then put it in concert with ALL the timing-dots lined-up. _ But if you lose-track of that gear's current timed-location, THEN you'll HAVE to trust just the timing-dots, (which are [sorta]- hopefully not already currently aligned).



" Are there any "surprises" I should know about before removing the cover? "

____ Other than avoiding pulling-out that points-gear along-with the engine-cover,
you should be aware of lining-up the oil-pump's drive-snout with the slot in the oil-pump gear, when replacing that eng.cover.



" What do I do next if the timing is correct? "

____ You mean if all the timing-dots are already all aligned ?
Then in that case, I'd say that you MUST have the wrong points-plate (as I've mentioned).
__ How about posting a pic of your points-plate ?


Hopeful-Cheers,
-Bob

[Chuck]

You can see from the butchered screw on the cam what most of the fasteners look like. The deeper I go with this bike the more I see past owners who didn't know or care what they were doing. Would making the adjustment slots bigger just be an easy way out? Please see the pictures attached.

[DewCatTea-Bob]

" Would making the adjustment slots bigger just be an easy way out? "

___ That could work but I'd hate to see such a nice stock-plate get messed-up.
It is (somewhat disappointingly) the correct plate (with the wider slots [than a n-c.Scrambler-plate] ).


Hopeful-Cheers,
-Bob

[Chuck]

The easy way is not the right way. I'll pull of the cover and see what's there. If I pull of the cover off and the timing gear come with it how do I put the gear back into engine? Can I separate the gear from the cover easily after the cover is off and place back in position and then put the cover on? Thanks for your help, I'll keep you posted.

Chuck

[DewCatTea-Bob]

" If I pull of the cover off and the timing gear come with it how do I put the gear back into engine? "

____ Once you get into it, you will then see how easy it actually would be to do. _ However, to make this job more worth-while, you really ought to try pulling-off the eng.cover without disturbing that points drive-gear,, as the added tear-down work would have to be done on the assembly-side anyhow !
__ Simply remove the AAU/cam-screw, then keep the shaft of the points-gear pressed-inward while the cover is pulled-off. _ (A rather thin screwdriver with long-shaft, or other handy shaft that's sufficiently thinner than the head-width of the [removed] screw, can be used to keep the AAU's retaining-shaft pressed inward.)
If you don't have help with that task, then only pull the eng.cover outward no more than 6 to 8mm at a time and each time then press the shaft-tip BACK inward (before the gear comes-out too far and gets disengaged & allowed to lose it's current mesh/timing). _ The cover should then come-off by the 3rd time it's pulled-outward (by that amount, as it has to clear about 15mm from the crankshaft-tip).
__ This way, you will then be able to CONFIRM whether that p.drive-gear was somehow set advanced from where it SHOULD'VE been set (with it's timing-dot properly aligned), or not.


" Can I separate the gear from the cover easily after the cover is off and place back in position and then put the cover on? "

____ Well yes but, you shouldn't do it that way. _ Besides, it's easier to loosen the screw in the end of the shaft, with that p.drive-gear still engaged/meshed with the oil-pump gear.
Once that screw is removed, that p.drive-gear/shaft may slip right-out of the eng.cover (from the inner-side, once the cover is off the eng.case) !
__ BTW, before you get started on the eng.cover,, remove the tower-shaft gear-cover on the cyl.head, and turn-over the engine until the timing-dots on that pair of bevel-gears are aligned.
That way, there will at least be a chance that all the gears behind the eng.cover will also have all THEIR timing-dots aligned as well.


Hopeful-Cheers,
DCT-Bob