Bultaco mk10 370, competitive or not?

[supersenior 50]

Bring them to the 2013 Classic titles in Qld (see main thread) and test them in the real world.

[JC]

John,

The MK10 Buls are a sweet bike. A few tho'ts:

Pomeroy was still doing well internationally on a MK10 in 76
(Yes I know Mk10s came out in 77 but what he was riding in 76 was more or less a Mk10)
Got a feeling Vic Allen was still on one in UK too in 77 & doing fairly well
Floody left Bul for KTM in 76 (IIRC) but never went as well on KTMs, for various reasons.

Parts supply for Buls is excellent  - probably best of all VMXers - & usually reasonably cost

The Bultaco blood in my veins would love to say, Go Bultaco, but...

The 250 Mk10 went back to 35mm forks (from 38mm on Mk9) & 125mm front brake (from 140mm on Mk9) to save weight.
Not sure if the 370 did too, but its likely.   Moto (on here) would know.

Rear suspension travel is somewhat limited on the pre78 Pursangs due to distance between swingarm pivot & c/s sprocket. Pivot is fairly hi in the frame too so the chain drags badly on top of swingarm if you just run longer shocks for more stroke.
MK11 swingarm is about 30mm longer & is useful mod (if its legal) for more travel.
Notably, Floods were lengthening the swingarm 30mm in 74 I believe. Took the factory another 4yrs to do it.

Bul gearchange is considerably longer than Jap if thats what yr used to, but easy enough to get used to. Somewhat similar to a Maico.

Nice handling & nice power but realistically they were a bit off the pace by 77 I would think.

[Husky500evo]

        John, you are welcome to have a skid on my '77 Montesa VB 360 anytime that I have it down your way. I hope to be taking it to CD10, if you are going there. I have fitted it with a YZ400D front end and a set of WP piggyback shocks, which seems to work pretty well. I had no intention of ever entering it in a national title event, while ever the 9 inch travel rule is in place, but I might reconsider it with this Monty, because I can drop the YZ forks down in the triple clamps and avoid changing the geometry of the bike with internal travel limiting spacers in the forks. The WP shocks have a shorter shaft stroke than the original Betors (but the same overall length) and give a touch under 9 inches travel in the rear. It is a bit harder with my '77 CR390 Husky because to do it properly , if you reduce the length of the forks, you have to reduce the length of the shocks either by internal spacers or shorter shocks. I don't have enough time to work on my bikes as it is, without having to do stupid stuff to modify them backwards from the way they left the factory.
         Also, if you wanted to consider another pre '78 model Euro big bore that is completely outside the square, a '77 Husky 390 AMX  might be worth looking at, (if you could find one). I have one in bits, that I am eagerly waiting to find the time to put it back together. I love Husky Autos and I think that it could be a real weapon compared to other '77 model bikes, especially with a Mossbarger reed block and a Paul Rooney ported cylinder  .

[Montynut]

I can remember a '77 Husky AUTO out dragging the field to the first corner at Dargle all day long you could not touch it. It dropped about a wheel length in the initial 2m off the gate then the front wheel stayed about 300mm off the ground for the entire start straight . It was just unbelievable to see it from another riders perspective. The guy riding it was no ‘A’ grader just an average rider like me but he pulled holeshot after holeshot that day

That is a very tidy VB you have there

[Mick D]

The guy riding it was no ‘A’ grader just an average rider like me but he pulled holeshot after holeshot that day

I hope I don't live until I am really old, cause I don't think I am going to have any Super left by the way I am spending it. So where can I get one of these Super auto weapons

[Husky500evo]

So where can I get one of these Super auto weapons

I think that a '77 390 AMX is a pretty rare bike in Australia. If you look at Husqvarna model ID listings, it shows the '77 model auto as a 360. But there was definitely a 390 AMX made in '77 and I somewhere have a copy of a Motocross Action magazine from mid '77, which incidently had a Bultaco MK10 370 Pursang on the front cover, that has a test on a '77 390 AMX. I think that the differences between the '77 and '78 390 AMX is the same as the CR390, with the '78 models having a larger tube size that the swingarm is made from and tapered roller steering head bearings (the '77 models had ball bearings in the steering head).

[JohnnyO]

Mark I'd love to have a ride on the Monty some day, not sure about CD10 yet.
JC thanks for that info, I tend to agree that Bully was a bit off the pace by 77 but I've yet to ride one and I'm sure they can be made a little better..

[JohnnyO]

So where can I get one of these Super auto weapons

I think that a '77 390 AMX is a pretty rare bike in Australia. If you look at Husqvarna model ID listings, it shows the '77 model auto as a 360. But there was definitely a 390 AMX made in '77 and I somewhere have a copy of a Motocross Action magazine from mid '77, which incidently had a Bultaco MK10 370 Pursang on the front cover, that has a test on a '77 390 AMX. I think that the differences between the '77 and '78 390 AMX is the same as the CR390, with the '78 models having a larger tube size that the swingarm is made from and tapered roller steering head bearings (the '77 models had ball bearings in the steering head).

I've got that mag stored away, better get it out and have a read. It's got Rich Eirstedt on the cover on the 250 bully..

[bigk]

I have a '78 390AMX (it is for sale) & it does not have tapered headset bearings. I've not heard of a '77 390AMX & if you check the Husky id lists, no such animal exists. It's damn fast when you get your head around no clutch or gear levers. I can't see any reason a '78 390 could not be classed as a carry over model with very minimal changes to '77.
K

[Husky500evo]

So where can I get one of these Super auto weapons

I think that a '77 390 AMX is a pretty rare bike in Australia. If you look at Husqvarna model ID listings, it shows the '77 model auto as a 360. But there was definitely a 390 AMX made in '77 and I somewhere have a copy of a Motocross Action magazine from mid '77, which incidently had a Bultaco MK10 370 Pursang on the front cover, that has a test on a '77 390 AMX. I think that the differences between the '77 and '78 390 AMX is the same as the CR390, with the '78 models having a larger tube size that the swingarm is made from and tapered roller steering head bearings (the '77 models had ball bearings in the steering head).

I've got that mag stored away, better get it out and have a read. It's got Rich Eirstedt on the cover on the 250 bully..

Ok, after looking through my old magazine stash, it appears that Alzheimers is kicking in. The June '77 edition of Motocross Action magazine has Rich Eierstedt on the cover riding a 250 MK10 Pursang (not a 370) and the Husky 390 test is on a CR, not an AMX. The article on the 390 AMX that I was thinking of, was in the October '77 issue of Dirt Bike magazine and they definitely state that it is an official '77 model. I have scanned the AMX test and will post it in the Husqvarna section, if anyone is interested.   

[Mick D]

Ok, after looking through my old magazine stash, it appears that Alzheimers is kicking in. The June '77 edition of Motocross Action magazine has Rich Eierstedt on the cover riding a 250 MK10 Pursang (not a 370) and the Husky 390 test is on a CR, not an AMX. The article on the 390 AMX that I was thinking of, was in the October '77 issue of Dirt Bike magazine and they definitely state that it is an official '77 model. I have scanned the AMX test and will post it in the Husqvarna section, if anyone is interested.

Hi mate, I would love to read that article if you can spare the time and are equipped to scan it for us.

By the time I was 23, I had owned 128 different motorcycles, and still to this day the only one I still miss and regret losing is my MK10250. A freind had a 370 Frontera, Beautiful rideable  power, but I was young and fit and loved the way the 250 boiled on to the pipe with enthusiasm. Rebored it once. The only failure was a the red coil thing under the tank. Never touched the bottom end, including the clutch. Hardly used that bit actually. Flogged it, but looked after it. I just loved the way it handled under push. I reworked the mechanical advantage on the front brake. Most reliable dirt bike I ever owned. loved it, still do. Could have made it even better these days. And is still one of the sexiest bikes ever. Pure Beautiful.

[Mick D]

[Husky500evo]

I have had a few requests to scan and post the 250 Pursang Mk10 test, so I will post it in the Spanish section . Unfortunately, I noticed that the centre page of my magazine is missing and this has the last page or two of the test. Hopefully, someone else can scan and post the missing bits.   

[FourstrokeForever]

Why no four strokes guys?

I've got a centre port XL350 (412) in what I think is a champion frame. I built it to look like a 4 stroke 76 CR Honda, but with real suspension. KYB factory forks @ spot on 9" and ohlins rear @ 8 1/2" wheel travel with a white brothers alloy swing arm. The thing is a blast to ride as it does everything extremely well, apart from the front brake which is a 76 CR unit. I'd like to try a different front brake set up but I want to keep it all Honda. So far it has been surprisingly competitive at club meets against the big bore YZ's and RM's, even with an unfit 120kg's of beer pig on board.
A mate has built another centre port 350 (450) and shoe horned it into a 77 AW Maico frame. He's still in the process of sorting it but going by all the praise the AW's get for their handling, it should be a good thing as well.
I enjoy having something different and thoroughly enjoyed building the beast, even if it did go "slightly over budget"!

[JohnnyO]

TBM no doubt there are hybrid 4 strokes that would be competitive in pre 78 and also the CCM, unfortunately they are not readily available and as affordable as the 2 strokes in this country..