Daytona Belt Replacement & Crank Pulley

[Old Jock]

So right now I'm in the process of tearing down the front of the engine to get into the timing case to replace the oil pump & gear mod from Joe Caruso.

It's going Ok so far no special tools used lined up the engine to the marks and used a rattle gun to undo the bolts on the pulleys and everything has stayed in place, although it is a bit scary how easy the cams can turn with the belts off.

However I was bit shocked when removing the belts, I could get the forward belt off no problem but to remove the rear belt I had to pull the crank pulleys first, once they were off I took off the belt.

Is this normal, surely even Guzzi didn't intend that you need to remove the crank pulleys to replace a belt?

Or did they?

Wondering about removing some metal on base of the casing at the pulley to see if that would help.

Anybody have a magic fix?



John

[Chuck in Indiana]

Wondering about removing some metal on base of the casing at the pulley to see if that would help.

That's the quick and dirty method of changing out the belts.

[dxhall]

That's the way they all are.  Removing the pulley isn't hard, though.  The threaded holes in the pulley are for a puller.
 

[dxhall]

Here's a couple suggestions on the oil pump replacement:

(1) use the shorter bolts that come with the pump.  DO NOT use the old bolts, which are too long for the Caruso pump and will foul the crankshaft.

(2) pack the pump with light assembly grease before you bolt it up.  Because of the way oil flows through the filter assembly on this motor, it isn't possible to prime the pump by putting oil down the rocker oil lines.  If you put it together dry, it may not have enough suction to draw. 

[blackcat]

“Wondering about removing some metal on base of the casing at the pulley to see if that would help.”

That is how I removed mine, and it was a fairly quick solution.

[Old Jock]

Ok thank you all for the answers & dxhall thanks for the extra tips on the grease and fasteners.

I got some tips from Joe and put them into a powerpoint show and alternately a pdf.

If anybody wants it drop me a PM

As I'm going along I'm taking the odd photo here and there in order to document how I went about it, so far it's been straightforward but a lot of work in my opinion, just to get to the belts.

See here for the pics, but that's all they are and I'm not very far into it, as this is all virgin ground for me.

https://photos.app.goo.gl/GsGblVvTeJhPL68G3

I agree removing the pulley is not difficult but I think it is pretty sloppy engineering on Guzzi's part that it forms a part of the procedure, you don't need to do that on a Ducati.

Guzzi could have come up with either a different pulley design or modified the casings in order that the belts would slide off.

Given that the nut and pulley are on the crank, it really is something I'd rather not be taking on and off regularly, one slip with that nut and you're in BIG trouble, plus the wear and tear on the threads.

Perhaps I'm an old woman but the thought of having to consistently undo a nut whose threads are on the crank as a regular maintenance item is an appallingly bad piece of design.

John

[Chuck in Indiana]

Perhaps I'm an old woman but the thought of having to consistently undo a nut whose threads are on the crank as a regular maintenance item is an appallingly bad piece of design.

You have to remember that this was a race engine, designed in the heat of battle. It is *not* your typical run forever Guzzi engine. The 4V was done as an add on as expeditiously as possible. On the original Daytonas, even the u joint/ drive shaft was throw away.
You only have to change the belts every 18000 miles or so. In the typical life of an engine, that isn't very many times.

[blackcat]

If you don't move the cam locations from this point, can you just remove the cover, replace the pump and put everything back together?

[Chuck in Indiana]

Theoretically, yes. What will happen, though, is the cams will move when you are doing all this. No big deal, really.

[weevee]

I'll soon be putting the steel gears in my bike, John, so I'll follow your thread with interest!

Regarding the belts:  I changed them on mine as soon as I bought it, and I know for sure I didn't have to remove the pulley.  So far as I can remember, the casing was intact beneath it too.  Odd!  (..or maybe I just didn't notice it had been ground back to give extra clearance?)  I suppose I'll find out for sure when I open it back up.

Steve

[Chuck in Indiana]

I'll soon be putting the steel gears in my bike, John, so I'll follow your thread with interest!

Regarding the belts:  I changed them on mine as soon as I bought it, and I know for sure I didn't have to remove the pulley.  So far as I can remember, the casing was intact beneath it too.  Odd!  (..or maybe I just didn't notice it had been ground back to give extra clearance?)  I suppose I'll find out for sure when I open it back up.

Steve

The castings aren't exactly the same. Surprise surprise.  On some, you can cave man the belt off without clearancing the casting. If you have the tools, taking the pulleys off is a walk in the park.

[Old Jock]

Thanks Steve, Don't know how much metal you would need to remove, I'm reluctant to take a grinder to the casings as it does not look like there is a lot of metal there

My bad it's not driven off the crank of course but off a stub shaft above driven by a gear wheel at 1/2 crank speed

Unless I was doing something really stupid I could not see any way to get the inner belt to clear the shoulders to get it free

My plan is just to go in now remove the cover and then do the mods. If the cams do move I suppose I'll have to get into trying to re-time it all as I don't see a way of locking the cams

From the picture though you can see the shaft positions so I hope I won't have to get involved with setting the whole valve timing up again, I'll also try to match mark the shafts to the timing case too, just a belt & braces

A friend has just done this a few months back and did not report any problems.

Chuck if you have any advice I'm all ears

John

[Wayne Orwig]

If you don't move the cam locations from this point, can you just remove the cover, replace the pump and put everything back together?

Doesn't the upper bit of the cam belt housing stay in place around the camshaft?

I don't remember needing to pull the pulley off of the camshaft. But then, it was ten years ago.

[Chuck in Indiana]

Really, as long as you have the left cylinder at TDC ready to fire, you can take the pulley off, etc. As long as the mark lines up with the tit on the casting when at TDC, you can put the belt on, and you're good.
IMG_5457 by Charles Stottlemyer, on Flickr
Same deal on the D side.  The cam will line up with the tit on the casting.
IMG_5456 by Charles Stottlemyer, on Flickr
The sequence is TDC ready to fire on the S cylinder, change the belts, stretch the S belt. Rotate 270 degrees so the D cylinder is TDC ready to fire, stretch the D belt.
Note that there is a vernier for fine adjustment of each cam pulley. Pay attention when you take the pulleys off.  Probably you don't want to mess with it if the engine has been running ok. The beauty is you "can" change the cam timing with a degree wheel, if necessary.

[Old Jock]

Just looked at the manual DOH!!!

Yes Wayne you're right you don't have to remove the top pulleys, wish you had told me earlier. Well that's certainly how it looks from the part book

The top parts of the casing can stay in place that way you don't have to remove the cam pulleys, that would have made life a little easier, Oh well even as it means I don't need to mess with anything up there from now on, so less chance of disturbing the shafts............. Thanks 

Must pay more attention

Now goes away to see where he put the cam pulleys and put them back onto the shafts 

Chuck thanks for that, I certainly do not want to mess with the "Very Nears" that's the stuff nightmares are made of

John

[blackcat]

Hmmm.....if you don't have to remove those pully's on the cams then it seems like a fairly straight forward job provided you can lock those cams in place or am I missing something? 

[Old Jock]

I would say fairly straightforward BC, just a lot of crap to remove

As long as the cams and crank are lined up to the marks and when the belts are removed.

After that as long as the crank doesn't move you are fine, even if the cams move you can just rotate them back to the marks.

As I'm trying to take pictures I should be able to put something together as a guide.

Just another thing I'm guessing here but are the Verniers the internal gears on the cam pulleys? If so I'd match mark them with paint, obviously not necessary for this job but it's a good idea

John

[Chuck in Indiana]

Hmmm.....if you don't have to remove those pully's on the cams then it seems like a fairly straight forward job provided you can lock those cams in place or am I missing something?

Good luck with doing that. There are springs involved, and things tend to move around when you are even taking the belts off.

Just another thing I'm guessing here but are the Verniers the internal gears on the cam pulleys?

Yes. Luigi didn't always get it perfect, btw. You can make them perfect with a degree wheel.
Sounds like you're on top of it now, John.. carry on. 

[dxhall]

It's not quite as simple as it first appears.  The cause of potential grief is that, if you follow the instructions in the manual, the right-side cam is under valve spring pressure when you remove the belt from its pulley.  When you bump the pulley as you put the new belt on, (you will), the valve spring pressure from the open valve will spin the cam.

If you've marked the pulleys, you can probably get it back where it was.  You can't be sure you've got it right unless you do the drill with the degree wheel.

[blackcat]

Good luck with doing that. There are springs involved, and things tend to move around when you are even taking the belts off. Yes. Luigi didn't always get it perfect, btw. You can make them perfect with a degree wheel.
Sounds like you're on top of it now, John.. carry on. 

I'm not second guessing you on this as you clearly know more than myself, but I didn't have any problems with the running of my bike after I changed the belts. I just removed the belts, installed the new ones and made sure the pully's didn't move.

Luck?

[Chuck in Indiana]

I'm not second guessing you on this as you clearly know more than myself, but I didn't have any problems with the running of my bike after I changed the belts. I just removed the belts, installed the new ones and made sure the pully's didn't move.

Luck?

Not at all.. as long as the pulleys didn't move, and obviously they didn't.
As dxhall said

When you bump the pulley as you put the new belt on, (you will), the valve spring pressure from the open valve will spin the cam.

And previously, I'd said..

Good luck with doing that. There are springs involved, and things tend to move around when you are even taking the belts off.

[Tom]

I'm not second guessing you on this as you clearly know more than myself, but I didn't have any problems with the running of my bike after I changed the belts. I just removed the belts, installed the new ones and made sure the pully's didn't move.

Luck?

(Edited)  No, skill.     Left out the comma.    

[dxhall]

Maybe my motor has the Special Low Friction Cam Lobe option. 

Seriously - part of the timing drill is to turn the cam counterclockwise until the exhaust valves open 1mm.  Then, with the cam in that position, you install the vernier gear in the inner part of the outer pulley.

The cam on my motor would never stay at the 1mm-open position.  When the dial indicator showed 1mm and I removed the tool which turns the cam (which you must do to install the vernier) the cam just spun backwards.

if your cam will stay in place at 1mm lift, you're livin' right.  Buy some lotto tickets.

[Old Jock]

Anybody got any idea where I can purchase a belt stretching tool?

Appears they are now manufactured from Unobtainium

John

[Chuck in Indiana]

Anybody got any idea where I can purchase a belt stretching tool?

Appears they are now manufactured from Unobtainium

John

<scratching head> Didn't I send you a drawing?

[Old Jock]

Sorry Chuck is it in that folder of tools

I'll take another look many thanks

John

[Joliet Jim]

<scratching head> Didn't I send you a drawing?

Could I get a copy of that drawing. I either need to change the belts or sell the bike :)

[Devildog]

Thanks for this thread, John. You are beginning to convince me to hire a professional when Joe's package arrives. Not for the faint of heart.

[Sasquatch Jim]

 I vote sell the bike.

[Tom]

'ey John, where did you buy your belts from and how much?  It's been awhile since I last check on availability and price.