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350 Sebring

Posted: Sat Nov 10, 2012 4:36 am
by jasontfloyd
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I got this bike for a steal and want to restore it. I think it is a mid-late 60's Monza 350 OHC.

The forks are shot, the tank seems to be original and has no dents. The engine is is decent shape. I took the case apart to do some investigating. The piston was rusted to the cylinder wall, but after a night of WD-40 it broke loose. Other than needing a new sleeve and piston, the engine is superb-no fins are broken and it still had oil in it. The electical system is also completely gone.

I would really appreciate some advice on where to go with it. I am thinking either a full restore or a cafe racer. My end goal is to ride it. I am a classic car guy and have never done a bike, but I love classic Ducatis and am excited for this challenge.

Also, what should I expect to pay for a project like this?

Re: 350 Monza

Posted: Tue Nov 13, 2012 4:57 pm
by TDF
Cool. Gotta start somewhere.

What part of the world are you located in?

TDF

Re: 350 Monza

Posted: Fri Nov 16, 2012 10:45 pm
by jasontfloyd
I am in the San Diego area. Seems to me it is a good place to have a bike like this.

Re: 350 Monza

Posted: Sat Nov 17, 2012 7:28 am
by TDF
If you decide which way you're going to go on it, if it's restore, keep me in mind. I'm cafe'ing a 66 350 Sebring, that was mostly complete. I might have a few parts you could use. Side covers, chain guard, front fender, forks, etc. Nothing's perfect, bike sat in a barn for a few years (decades).

Also, I think you're bike is a 66 or 67 Sebring, if the motor really is a 350. The Monza was a 250, everthing else being the same.

TDF

Re: 350 Monza

Posted: Sat Nov 17, 2012 10:43 pm
by jasontfloyd
TDF, thanks for helping me with the model. I am still deciding what I am going to do with it. I am leaning towards cafe, mostly for price reasons. If you dont mind my asking, how much are you expecting to put into yours?

Also, what kind of shape are the forks you speak of? And what forks did you go with?

Re: 350 Monza

Posted: Sun Nov 18, 2012 6:37 am
by TDF
I decided to Cafe mine because I never could quite get into the looks of the 66 Sebring. The squareness kinda bothers me. Had it been a 65 I'd have had to restore it. As to price. Well I gave a grand for the bike with a freshly rebuilt motor. And have almost another grand in the body kit from AirTech (the Super Sport Single kit), plus a few other bits I had to pick up off of ebay etc. So I'm probably somewhere short of $2500 right now and will probably be able to complete it for under $5k. But that being said I'll do all the machining of brackets, welding, seat recovering etc. myself and the painting will be done by my youngest brother, so labor doesn't really get factored into my price. This seems to be fairly close to the total my youngest brother ended up with when he took a 71 BSA twin from rat to race replica. I'm quite sure he was able to keep the total under $5k, but again all labor was done in house. (see the two before and after BSA photos below)

The forks I have on it now are a 35mm set off of a later wide case Ducati dirt bike of some sort, I think they're Marzocchi's. The triple trees swapped over with out any issues. I may not run the Duck forks as they are a bit nicked up, and I'm leaning towards wanting to run a front disc brake so I'm needing to get to our shed of parts bikes and see if I can come up with a set of 35mm forks off of something, Honda CB550 might be able to be made to work. Plus I got a guy that came up with a set of Ceriani triple trees and forks that I need to get a look at, and do some measuring.

My original forks seem to be in decent cosmetic shape on the outside at least, and aren't stuck. I can't remember how the tubes under the covers looked without pulling them apart. The first photo below is my Sebring, as bought.

TDF

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Re: 350 Monza

Posted: Mon Nov 19, 2012 7:16 am
by jasontfloyd
I think that I am going to pursue to the cafe option. I have a salvage place within 5mi of my house that is full to the brim of 60's-85's model parts. The biggest challenge is going to be the forks. I am hoping that I can find a whole front end that has mag wheels and a disc brake. Once that challenge is done, I think I can finish this bike with little to no problem. I am going to pursue the honda 550 option also, thanks for the tip.

Re: 350 Monza

Posted: Mon Nov 19, 2012 4:02 pm
by radecal
Hi TDF,
That is one beautiful Beeza your brother put together especially considering what he had to start with!
Regards,

Re: 350 Monza

Posted: Mon Nov 19, 2012 4:46 pm
by TDF
Jason, you're probably right that the forks will be the harder part. They were certainly challenging on the BSA my brother built. That's a front end off of a Yamaha XS650 on there. He cut the top and bottom off the steering head on both bikes and welded the top and bottom off the Yamaha to the left over part of the steering head on the BSA. Just so he could run the Yamaha triple trees. Then converted that over to tapered roller bearings. That kid has more ability that I think even he realizes. On my Ducati the triples off the later Ducati dirt bike are aluminum and decent looking and allow me to upgrade to 35mm forks with opens up a world of options. Anything can be accomplished if you have enough money or enough ability.

TDF

Re: 350 Sebring

Posted: Fri Dec 21, 2012 7:08 am
by jasontfloyd
Alright, I gotta ask this very painful question. And Im glad that none of the purists out there know where I live...

I wanna make some frame modifications. I know this will drop the value in my bike; but I love MOST of this duc, not all. I want to shorten the frame underneath the seat pan so I can put an upturn brat seat on it. I also want to drop the top suspension pegs down onto the frame so the rear springs look a little more like the GTV, this will drop the swingarm and make the bike a little taller.

I am also planning on some other mods that will be less permanant. I am going to take a donor front end and put it in, and a cdi electrex world ignition.

I would really appreciate some opinions. Let me have them, I can take it. I know that I can never get the original bike back, but everyone said the same thing about my '77 Camaro.

Re: 350 Sebring

Posted: Fri Dec 21, 2012 9:54 am
by chimera
Ducatis are a good platform for all kinds of customs. The “square style” Monza and Sebring (which yours appears to be) are probably the least appreciated of all the ‘60’ vintage singles so they get customized or made into racers. Nobody’s gonna bust your chops about losing another. It would be unfortunate to loose a perfectly good frame though. If you want to cut yours up, I’d be glad to trade you a frame that has a bent seat loop that you could cut up with no remorse. All the frames are basically the same for the 250’s and 350’s, just some different brackets. I’ve been told that Yamaha RD350 forks will drop right in to the Ducati frame but I’ve never tried it myself. I do have a chassis that had R5 forks installed but the triple clamps were Suzuki. If you want different forks, the easiest way is to get 35mm W/C scrambler triple clamps, then you can use any 35mm fork. If you want to raise the rear end, why don’t you just install longer shocks? Chances are the shocks on your bike are shot anyway, the stock shocks are really cheap and are often found to be bent/rusty/leaking, etc. when disassembled. If your motor is a 350, it should have nine fins on the cylinder, have “350” cast into the left side cam bearing cap, have a valve compressor lever on the exhaust valve cover and a second, smaller lever welded on the clutch lever perch to activate the lever on the valve cover. Also, the engine number (located on the cases in front of the cylinder) should say “DM350”. Matt

Re: 350 Sebring

Posted: Sat Dec 22, 2012 4:41 am
by jasontfloyd
Thanks Matt,

My engine is certainly a 350. It is stamped and I even measured the cylinder and did the math. I am thinking about a cafe/brat. I will keep the tank, the engine, and the rear end. But I will make some smaller frame mods, mikuni carb, and a front end that is ten years newer with a disc brake. I have high hopes for the cdi ignition from electrex world. In the end, I want to make this a bike I am really proud of. Not only because I did the work, but because it looks like noone else's and just the way I want it. Not to mention, one that I can ride.

Re: 350 Sebring

Posted: Thu Nov 21, 2013 6:46 pm
by jasontfloyd
Fellow single lovers,

It has been such a long time since I posted on my project. I have done a lot in the past year or so.

1. I split the cases and cleaned everything out. I almost quit on the project when I had a hard time getting the main gear roller bearing back together in the housing. But after a lot of work, the case is back together and the transmission cycles through all the gears again.
2. I had Randy from Motorcycle Dynamics hone the cylinder for me. Getting everything back together took a while, but the engine is in one piece for the first time in about 18 months.
3. I installed an Electrex World CDI ignition. It was really simple and much cheaper than replacing all of the stock electric parts individually. I would say it was a great buy, but I won't be too sure of that until I have a couple thousand miles on the rebuild.
4. Randy from Motorcycle Dynamics did a custom head swap with a 82 Kawasaki 650. The bike now has a reliable disk break and it looks good.
5. New sprockets, chain, headlight, custom brat seat, and rear shocks.
6. Lastly, new Mikuni 32mm carb.

After all of that, the inevitable has come to pass. I cant get it started. I have spark, fuel (tried gas and starting fluid), and air. I checked the timing. I think I am pretty close to 36 deg max advance. All I get is a pretty substantial backfire every 1 in 10 kicks. I tried bump starting it...nothing. I also checked and rechecked the cam timing. I lined all of the dots up. I'm getting to the point where I have exhausted all of my motorcycle knowledge, which isn't much. The next step is to hand it over to someone who may or may not know vintage ducati singles, overpay them, and hope for the best. I just don't want all of this time, money, and emotion to sit in my garage for the rest of my life.

Suggestions?

-Jason

Re: 350 Sebring

Posted: Sat Dec 28, 2013 1:53 am
by eternally_troubled
That sounds annoying! Did you get it to start in the end?

You mentioned the advance - as far as I know, it shouldn't need much advance at idle/lower engine speeds, the timing of the spark should advance as the engine
speed inreases.

Anyway, best of luck!