Beautiful Paso with a broken engine case... what do I do?

discussions specific to the 750 Paso

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drewskies944
Posts: 8
Joined: Fri May 03, 2013 3:21 am
model: 750 Paso
year: 1988
Location: Canada

Beautiful Paso with a broken engine case... what do I do?

Post by drewskies944 »

I have an 88 Blue North American Market Paso that was running and wonderful until my chain snapped and cracked my engine case. I love the bike, but I'm not sure what to do with it. the tire problem and the availability of parts makes this bike hard to keep on the road. it will never be a museum piece, but it looks great, was in fantastic running order, and was my first motorcycle which was gifted to me by my father (pasophisto).
It has the upgraded ignition system, the upgraded twin intake manifolds with Dellorto carbs and stainless reusable K&N filters, period correct Yoshimura stainless exhaust, the engine had a full valve adjustment 50 kms before the chain let go.

every once in a while I see 750 Pantah engines for sale, but they are costly (especially to ship) and I'm not sure its the route I want to go. I have tons of parts for the machine that could help with a package deal sale to avoid parting it out. But parting it out is also another option. I guess maybe the best financial decision is to replace the motor, then sell it as a working bike, but then it has a non original motor and worth even less?

On the bike:
-NEW golden tyres in original 16' spec (500 km tops on them)
-14 tooth front sprocket
-replacement OEM rear shock
-replacement voltage regulator
-stainless braided front brake lines
-fully functioning dashboard
-rebuilt starter motor
-new battery
-CORBIN seat

Other parts:
-spare right +left OEM front fairings (body colour)
-spare right +left OEM rad covers (body colour)
-spare right +left rad covers (unpainted)
-original rear shock
-spare brake rotors
-2 complete sets of old tires
-1 front tire mounted on a spare front wheel
-rear swingarm (complete with bearings and axle)
-spare right +left oil rads
-some electrical (voltage regulator, and other misc things)
-original 15 tooth front sprocket
-spare dashboard


what are your guys' thoughts on my situation?
what is all this stuff worth?
is anyone interested in what I have?

ready...set....GO!!!
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ducinthebay
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model: 750 Sport
year: 1990
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Re: Beautiful Paso with a broken engine case... what do I do

Post by ducinthebay »

If the bike is basically sound, and the case only has a crack from the chain, I would be tempted to do a temporary fix, and ride it. If, on the otherhand, the ouput shaft has a large amount of play, the you would be doing more damage.

Short term: Tip the bike on the right hand side, spray the crack in the case with Brake Cleaner to degrease, then fill the crack with JB WELD or other metal filled epoxy. Let dry, fill with oil, have fun. Watch your chain tension.

Medium term: find a spare engine from a Paso and install. A Sport or Pantah motor won't be the same at the pivot, but I can't explain exactly what the difference is.

Full Monty: Pull the engine, tear it down, and have the cases welded. Put in all new bearngs, gaskets and seals. Port and polish the heads and put in HC pistons, Keep the bike till you die, or will it to your kids.

...If I needed another project.......

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
drewskies944
Posts: 8
Joined: Fri May 03, 2013 3:21 am
model: 750 Paso
year: 1988
Location: Canada

Re: Beautiful Paso with a broken engine case... what do I do

Post by drewskies944 »

thanks for the input Phil. short term option is out for me because of the nature of the impact from the chain. Re: medium term, the Paso 750 motor is not a pantah 750? I thought they were the same, and pardon my ignorance, but what is the 'pivot'?

also, if I was to sell the broken bike complete with spare equipment... what do you think a reasonable price would be?
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ducinthebay
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Re: Beautiful Paso with a broken engine case... what do I do

Post by ducinthebay »

The pivot is the swingarm pivot which is in the cases just behind the sprocket. Different years and models did it a bit differently. The Sport was the same as the 750 F1 and Pantahs, with bushings in the cases, and the pivot pin moved with the swingarm. But on the Paso, the bearings are in the swingarm, and the pivot pin is stationary to the cases.

Don't know how difficult it is to change those out without machining the cases.

Is your output shaft loose compared to the cases? Can you take a photo so we can help you assess the extent of the damage? If you can even JB weld up the cases enough for a test drive, you will get more money for the bike.

In the condition its in, not running, you might get $800. If someone can at least test drive it to confirm everything else, you might get $1500 - $2k. Of course you should disclose the chain mishap and the broken cases. Let the new owner decide how to fix it.

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
drewskies944
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Joined: Fri May 03, 2013 3:21 am
model: 750 Paso
year: 1988
Location: Canada

Re: Beautiful Paso with a broken engine case... what do I do

Post by drewskies944 »

this is the damage to the engine. there is no reason for me to believe that there is damage or play regarding the output shaft, everything was groovy and tight until the chain flung forwards, I turned the engine off right away as the oil poured out, and haven't turned it over since. SO what is broken is.. the left outer cover, and the case. JB Weld isn't fixing this one unfortunately
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ducinthebay
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Re: Beautiful Paso with a broken engine case... what do I do

Post by ducinthebay »

Yeah, that would take more than 2 tubes. :-P :shock:
The outer case is easier to find than the center case, and those are matched when they make them, so getting only one side isn't a good idea.
Finding a spare engine is your best bet. Since a Paso motor fits only a Paso, it will be either really cheap, or really expensive. Limited supply, but also very limited demand.

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
nickta
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Re: Beautiful Paso with a broken engine case... what do I do

Post by nickta »

There was a P750 that had a Monster 750 motor fitted into the frame a while back. This could also be an option, as the Monster motor would be a bit easier to source.

Update the motor (and carby's, or even fuel injection!?), dismantle the old and part out anything of value and away you go on a Paso on the outside with a slightly modern motor on the inside.

Cheers.

Nick.
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Re: Beautiful Paso with a broken engine case... what do I do

Post by Duc750 »

Find a new motor/ cases - you only need the case and keep it - they don't make 'em like they used to !
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Re: Beautiful Paso with a broken engine case... what do I do

Post by higgy »

That is well beyond JB Weld however http://www.alumiweld.com/h2uaw.html will do it

so will DEVCON which is a 2 part epoxy you add aluminium filings too, very strong easier to use than Alumiweld and is completely machinable once cured. I have used it in the past to enlarge the transfer ports on 2 stroke engines and it has lasted for 20 years soaked in oil and under constant vibration
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There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
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MarkST
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Joined: Mon Dec 15, 2014 11:05 am
model: 750 Paso
year: 1987
Location: Sleepy leafy South Birmingham UK

Re: Beautiful Paso with a broken engine case... what do I do

Post by MarkST »

nickta wrote:There was a P750 that had a Monster 750 motor fitted into the frame a while back. This could also be an option, as the Monster motor would be a bit easier to source.
That's probably not quite as straightforward as it would first appear.

Are the two engine/frame mounting bolts the same size in terms of thickness?
Is the swingarm fitment the same size in terms of width at the engine/swinger mount point and connecting rod/axle diameter? - will this have implications as to whether any suspension modifications will need to be made if using the monster swinger ?
Will the front sprocket be perfectly in line with the rear sprocket if using the Paso swinger and rear wheel? Probably not.
Will there be any electrical implications re different types of voltage regulator/rectifier etc?
Will there be issues with the exhaust - different diameters at headers etc?
Will the tacho and speedo be issues to deal with?
etc. etc.

I know anything can be made to fit anything, and I know there's Paso's out there with ST and 748 motors and the like in them, and I really do enjoy reading about all that stuff, but it's not just simply a case of buy a Monster motor, throw it in, and away you go.

I'm pretty sure that the early Cagiva Elefant 750 motor is the same as the Paso 750, which will allow for a broader search, and I'm equally sure that somebody more knowledgeable than myself in this area will confirm whether this is correct or not.

I'm up for having the cans btw, should I pm my address? . . .

Thread of the year so far in my book, and best of luck with it drewskies.
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MarkST
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Re: Beautiful Paso with a broken engine case... what do I do

Post by MarkST »

Was it something I said ?
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Derek
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Re: Beautiful Paso with a broken engine case... what do I do

Post by Derek »

MarkST wrote:
nickta wrote:There was a P750 that had a Monster 750 motor fitted into the frame a while back. This could also be an option, as the Monster motor would be a bit easier to source.
That's probably not quite as straightforward as it would first appear.
Are the two engine/frame mounting bolts the same size in terms of thickness?
Yes. All the motor mount bolts are 10mm up to 2000 when they were increased to 12mm
Is the swingarm fitment the same size in terms of width at the engine/swinger mount point and connecting rod/axle diameter? - will this have implications as to whether any suspension modifications will need to be made if using the monster swinger ?
I don't know about the pivot but substantial changes would need to be made to the frame to take the rocker mounting for the Monster suspension if it's swinging arm was used.
Will the front sprocket be perfectly in line with the rear sprocket if using the Paso swinger and rear wheel? Probably not
Agreed, probably not but shouldn't be unsurmountable with the right gearbox sprocket.
Will there be any electrical implications re different types of voltage regulator/rectifier etc?
No that should be a straightforward plug and play.
Will there be issues with the exhaust - different diameters at headers etc?
I don't think so. I'm sure the monster ports are the same.
Will the tacho and speedo be issues to deal with?
No. The speedo on both bikes is driven from the front wheel and the tacho drive from the horizontal camshaft. I fitted ST2 heads and barrels to my 907 but had to get the horiz head machined to take the tacho drive.
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MarkST
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Re: Beautiful Paso with a broken engine case... what do I do

Post by MarkST »

Derek wrote:No. The speedo on both bikes is driven from the front wheel
But the Paso 750 front wheel is 16 inch and the Monster front wheel is 17 inch, so you'd have to use a speedo off one of the 17 inch wheel bikes.
Derek wrote:and the tacho drive from the horizontal camshaft. I fitted ST2 heads and barrels to my 907 but had to get the horiz head machined to take the tacho drive.
Interesting stuff Derek. I love reading about that kind of thing.
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paso750
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Re: Beautiful Paso with a broken engine case... what do I do

Post by paso750 »

But the Paso 750 front wheel is 16 inch and the Monster front wheel is 17 inch, so you'd have to use a speedo off one of the 17 inch wheel bikes.
this topic is only about replacing or fixing the engine/case so that`s not relevant :truck:
angelix
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Re: Beautiful Paso with a broken engine case... what do I do

Post by angelix »

That is fixable, it will take some work and a good welder, but I have seen worse damage repaired.

if it was my bike I would not think twice, I would fix it.

One option is to repair your engine, the other is to get a set of cases from fleabay and fill them with you engine parts.

Third option is to get an egine from a donor bike, even counting shipping it might not be that expensive.
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