tech question - belly pan

[towelie]

I just converted my street bike in to race trim but will this belly pan pass the tech? It's a 9x13 baking pan about 1 inch deep. Also is the exhaust pipe OK? It has DOT race tires and yes, the kick stand will be taken off.

http://mywebpages.comcast.net/shonda/MZ/bike.jpg

http://mywebpages.comcast.net/shonda/MZ/left.jpg

http://mywebpages.comcast.net/shonda/MZ/right.jpg

http://mywebpages.comcast.net/shonda/MZ/exh.jpg

Thanks!

[Eric Kelcher]

5.2.23 All 4-stroke machines must be equipped with a fluid catch pan of sufficient size
and heat-resistant material to contain the contents of the crankcases in the event of
an engine or crankcase failure. Minimum capacity of the fluid catch pan is to be 3
quarts.

I think that pan would not hold the 3 qts.

The exhaust looks fine other than it is hard to tell from the exhaust pic if it would drag in right hand corners.

[Ridgeway]

Yeah, pan doesn't look too kosher to me.

Even if it did hold 3 quarts, anything that it did collect would slosh out at the slightest hint of lean, braking, or acceleration.

Maybe see if you can get a buell or SV bellypan and make it work?  Shouldn't be that costly.

[towelie]

Thanks for the advice. back to wrenching...

[SVbadguy]

The exhaust running under the bike makes it a little more difficult.

For my DR650 it was pretty easy.

Find a tupperware container of a sufficient size to use as a mold for fiberglass.  Trim and reapply fiberglass until you get the desired size and shape.

A bellypan providing coverage for the area under your engine will likely need to be about 3 inches deep to have the necessary fluid capacity with room for sloshing.

[towelie]

good thing I had a universal belly pan in the stash...
I didn't use it at first because it hits the exhaust pipe but hopefully the triple layer of insulator will help. BTW, the bike is MZ Skorpion Tour.

Is this good to go?





Thanks!

[MZGirl]

I've made 2 bellypans for my race MZ.  For the first one I found a lower from some bike out of the bodywork pile at a local shop.  The top of it was cut off so that it could fit around the engine, and I fiberglassed a dam in the back to make it fluid retaining.

A crash ripped that one apart, so for my second one I made it from scratch.  My husband had a spare, unpainted lower from a TZ250.  I gooed it up with petroleum jelly, made a plaster cast of it, prepped the mold, and fiberglassed up a bellypan from scratch.  That one was much stronger, and I'm still using it on the bike  (pic below).

I've been racing an MZ quite successfully for the past 3 years, so if you have any questions, just let me know.  http://www.precisionstrikeracing.com .  They are fun little bikes!  I'm probably going to race mine forever.   8)

[towelie]

Hi there! Nice to see you here! We met at Mid-OH. I was on Duc 750ss.

Thanks for the info about your belly pan. I remember your MZ had Ducati's wheels on it, did you need to modify to fit it in there? does it make changes to handling characteristics?

[MZGirl]

Ah yes!  I remember meeting you!  Welcome!   :)

I'll let Zac reply about mounting the Ducati wheels, as he had to do some modifications to make it work.  They are lighter than the stock wheels, and I can now run the next larger tire size.  I was starting to have traction issues with the smaller size.  I didn't notice any significant handling issues with the change.

[Zac]

Hi Honda.

I'd try to get your exhaust headpipe up closer to the engine.  As I remember, the stock headpipe sat pretty close to the bottom of the engine and there was no problem fitting it in the belly pan.  With your setup it won't take much to drag the exhaust, especially if you are running stock rear ride height.

I found a couple old pictures of the bike with the old bellypan.  You can see the cut out on the right side were the exhaust came out:





The belly pan was (and is) mounted at the front with an aluminum bracket I made that attaches to the lower radiator mount, and at the back with two small aluminum brackets that attach to the holes in the frame where the centerstand bump rubbers went.

As for the Ducati wheels, the front was easy.  The Ducati's rotor will line up perfectly.  I had to replace the wheel bearings and internal spacer with 20mm bearings for the MZ axle (the old ducati SS used a 17mm axle, they changed (around '95?) to a 20mm front axle, so later Duc wheels don't need this change).  Then I just made new external spacers and everything bolts right together.

The rear was a challange.  The Duc hub is wider, so I machined both sides of the sprocket carrier to move the sprocket closer to the wheel centerline (including the cush drive pins) to match the MZ chain offset.  I machined down the Duc left wheel spacer to get the correct wheel offset.  I then machined both sides of the MZ brake caliper hanger to align the caliper with the rotor, and to fit the MZ swingarm width.  The Duc rear rotor was slightly larger than the MZ rotor, so it could have been turned down to fit, but my lathe isn't big enough.  I instead used a first-gen R6 rear rotor, which bolts up to the Duc wheel and is quite a bit smaller in diameter.  The caliper now sits out too far radially with the small disk, but half the pad sweep is still more than enough rear brake.  Someday (after I get my mill) I'll just machine a new brake caliper hanger.

-z.

[MZGirl]

I found a couple old pictures of the bike with the old bellypan.  You can see the cut out on the right side were the exhaust came out:

Here's a better pic showing the exhaust cut-out.

[towelie]

Thanks for the info. :)
I guess Duc wheel conversion seems like lot of work... so long for the idea of sharing wheels between Duc & MZ... :(