Author Topic: Bultaco fragility?  (Read 5935 times)

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Expat

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Bultaco fragility?
« on: August 17, 2008, 06:10:08 PM »
Occasionally seen posts about Bultacos( Pursangs??) being fragile.

What are the weak points and can they be corrected with modern technology ?

Interested in buying a 360 Pursang.

Mark Austin

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Re: Bultaco fragility?
« Reply #1 on: August 17, 2008, 06:41:31 PM »
Hi Expat,

I have lots of Bultacos and the "legend" of fragility is bullshit...

The best way to set up Bultacos is to throw away the original ignition and carburettor. Replace the ignition with something electronic - preferably Japanese (PVT is the expensive option, lots of Yamaha stuff can be made to fit) and replace the carby with a well set up and jetted BRAND NEW Mikuni - (ie do not buy a used carby EVER!!!) and you'll have a great faithful, simple and easily maintained VMX weapon.

They are fast and handle well - you won't regret it if you have them set up and built well, and there is a strong network of suppliers around the world, including two in Australia. Peter Schoene in Melbourne (Bultaco Parts) and Don Newell in Brisbane.

One great thing about Bultacos is that all models are basically the same, the same engine, running gear etc, so most parts are available and can be made to fit.

Cheers,
Mark

Offline JC

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Re: Bultaco fragility?
« Reply #2 on: August 18, 2008, 12:55:48 PM »
Oh yes, the myth of bultaco fragility.

Hi Expat, I concur w Mark on this. In my view its on a par w Maico-breako, usually perpetrated by people who had little/nothing to do w them, weren't up to doing basic maintenance or perhaps got a lemon (didn't every make have a few of those?)

Much of it stems from the 60's, but wasn't every competitive bike fragile then? Remember the british stuff! Materials & quality controls weren't nearly as good then as even the 70's stuff.

Occasionally they did have a 'bad' model, eg the 1st Astro which apparently had too-little bigend clearance & seized frequently, but is easily fixed.

My bro & I had several bultacos (& a couple of maicos, among others) & they were always stone-reliable & 2nd/3rd-kick starters w just basic regular maintenance. Ours all had standard carbs & electrics too. We couldn't afford anything else. I still have my 1st one (M63 71 SherpaS) & the only new one I ever had (76 M167 pursang)

The early ones needed some jetting refinements & I'm told eletrics could be suspect (but ours never were). Brakes weren't great then but thats easily fixed w modern linings. 360 engines can be improved w roller LHS main bearing on crank like later 370s had. Keep an eye on primary chains. Gear selection can be improved w a mod to the drum.

Many found the (early) RHS shifting & LHS kickstarting awkward. If you rotate the kickstart lever forwards on the spline & kick backwards w the right leg while standing next to the bike, its easy enough to get used to & they start readily, but there is a bit of a 'technique' to it. And gearchanging requires more lever-throw than a jap bike but that's not hard to get used to either.

Of course somebody will bag them on account of one bad experience, but you'll find such people w every make. They had all the important stuff for a competitive bike - handling, power, plush suspension, lightweight etc. I still have not ridden a 70s 250 that explodes out of corners like a well setup 'pomeroy pursang' M120/135. Others 250s made more power but none made better power that, combined w the flyweight, hooked up & exploded out of corners like a scalded cat.

They were/are simple but very effective - much more than the some of the parts. Theres a certain synergy to them that gives them a charisma which many find addictive for a 70's bike.

Talk w Don Newell (Bris) & Peter Schoene (Melb) about setup 'secrets' & I doubt you'll be disappointed if you own one.

Offline Maicojames

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Re: Bultaco fragility?
« Reply #3 on: August 19, 2008, 03:50:28 AM »
The myth is also prevalent in the US. While I have seen some less than perfect castings poilshing Bultaco parts, the metallurgy definitely improved in the 70s.
Also, the parts network for Bultaco is outstanding. I have ridden 73-77 250s and 360/370s-they are among the easiest bikes to ride fast. IMO, they are drama free-that is no big hit, no twitchy handling, no problems.

At least here in the US, they are way easier to get parts for than most Vintage Japanese bikes, and IMO handle better with perhaps the best 250 engine.
Shifting? For a comaprision.. To me, a Maico shifts like a great shifting Jap bike-like a Suzuki or Honda-the Bultaco has a just a bit more travel to shift, and the CZ has a very long throw.
The Pusangs are very popular for a good reason.
Life is suddenly very Monaro

Offline Tahitian_Red

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Re: Bultaco fragility?
« Reply #4 on: August 19, 2008, 04:05:35 AM »
James,

The thing I see half of the time I'm searching for a Pursang frame is a broken rear frame loop.  That is the only thing I have ever heard about breaking on a 73-75 Bultaco frame.
The "Factory Novice"
California, USA

'74 Suzuki TM100, '75 Bultaco 250 Pursang, '77 Honda XR75, '77 Suzuki RM125B, '77 Yamaha YZ400D, '79 Honda CR250RZ Moto-X Fox Replica, '83 Honda ME480RD Mugen

Offline Maicojames

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Re: Bultaco fragility?
« Reply #5 on: August 19, 2008, 04:45:52 AM »
Sure, but Hugh's sells a replacement loop. This was due to bike being looped, or people pushing on rear of bike-passengers etc.
Life is suddenly very Monaro

firko

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Re: Bultaco fragility?
« Reply #6 on: August 19, 2008, 08:24:23 AM »
I concur with all about the "Great Myth of Bultaco Fragility" and the extremely annoying and totally innacurate "Maico Breako" reputation. Much of the blame on this can be thrown at the mororcylcle press of the day, particularly American Dirt Bike Magazine. I don't know what the problem was on their tests back then but they had a inordinate and totally unrepresentitave amount of siezures, broken frames and loose bolts on all of their test bikes. Hardly a test went by when something major didn't fall off or break on a bike. Super Hunky created the Maico Breako term himself yet privately he told me that Maicos are among the more reliable Euro bikes. The same goes for Bultacos. It seemed that every time they tested one the damn thing siezed.

Firko conspiracy theory #973 is that in the early days there was a little bit of Rock'n'roll anarchy involved among the dirt bike press. They'd report blowups, breakages, non existant evil traits and other maladies that weren't really true in an attempt to create their own reputations as no bullshit, non compromising, "the big factories can't buy us" proper invesigative journalists and to give their magazines a touch of seventies hip angst.

This attitude was prevalent when they tested certain brands, most notably certain Spanish, British and nearly all Japanese bikes. I believe that the bad press had a twofold effect. One, it prompted many of the factories, especially the Japanese to pick up their game and rapidly improve the product. Unfortunately the bad press also contributed to the eventual demise of many small brands.

Offline JC

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Re: Bultaco fragility?
« Reply #7 on: August 19, 2008, 09:26:38 AM »
Yes I think a lot of it was the media/press of the day too. I was once told that GE at ADB couldn't master the LHS kickstarter, had a bigbore kick back on him one day, & hated/bagged bultacos ever after.

firko

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Re: Bultaco fragility?
« Reply #8 on: August 19, 2008, 09:41:46 AM »
 GE also had a bit of a "problem" with Huskys for quite a long time.

TooFastTim

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Re: Bultaco fragility?
« Reply #9 on: August 19, 2008, 07:06:21 PM »
and to give their magazines a touch of seventies hip angst.

 ;D

Offline BultacoMacca

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Re: Bultaco fragility?
« Reply #10 on: August 21, 2008, 02:34:31 PM »
Poor G.E. will probably find it ironic then, that a Bultaco mk6 325cc won the "Geoff Eldridge trophy" for pre '75 bikes (thanks to Klub Kevlar & Firko) at Crawford River Classic just gone. Ha!

Broadsta

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Re: Bultaco fragility?
« Reply #11 on: August 21, 2008, 09:54:14 PM »
Hi guys, i have a 360 mk7 with a 36mm mikuni. i would be interested in some jetting tips,i'm busting to start it for the first time this w/end after a 2yr build,but am a bit hesitant in case the jetting is to lean. Any help would be appreciated.

firko

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Re: Bultaco fragility?
« Reply #12 on: August 21, 2008, 11:24:28 PM »
I'm glad the trophy's in good hands Macca.