Bultaco Model 124 1974 250cc

[trialsrfun]

How might I identify a Bultaco Model 124 & what are the + & - of this model, best sprocket sizes, useful info etc

[big john]

How might I identify a Bultaco Model 124 & what are the + & - of this model, best sprocket sizes, useful info etc

Model 124 Sherpa has the model/year 1974 two piece Pursang rear hub, oil in swinging arm for chain lubrication. Gear change was on the right hand side, rear brake by rod on the left hand side. Frame was the first with the reinforcing tubes from the footrests up to the top tube. UK models had blue and silver homerlite tank seat unit. European & USA models had the Kit Campeon fibreglass tank seat unit, which was scalloped to fit the new for 1974 frame. The engine mounts were still welded to the seat tube. 250 motor still had the rounded close fin configuration barrel (model 125 - 325cc version had the squarer wider finned barrel)

Hope this helps.

Big John

[trialsrfun]

Thank you Big John it certainly does help, I am sure it is a 124 now. The exhaust is chromed with a similar but different (slimmer & smaller) exhaust to the one on my 199A, might this be the banana or clubfoot exhaust I have heard of these but have no idea which is which or what these silencers look like.

The rear hub differs from the one fitted to the 199A, it has raised, rounded strengthening ribs running across the brake drum, does that have a chrome liner. The front hub appears the same as the 199A. Carb appears to be an Amal 27mm concentric. Cylinder fins rounded and closely spaced with a screw in exhaust pipe collar. Homerlite alloy tank, seat unit is fitted.

Edited August 4, 2010 by TrialsRfun

[john collins]

All exactly as Big John states

I think you will find this is the model featured on the front of the haynes Bultaco manual

One tip - they can be a pig to start - you need to really hold tickler down and waste a bit of fuel - and as soon as it starts up - hold tickler down for a few seconds more - after this all will be OK

[woody]

Bit confused as you don't mention the engine or frame numbers. The first digits of these denote the model type, so Model type 124 begins with 124

Front exhaust pipe is chromed, rubber joint to a separate middle silencer, rear silencer could have been fitted from any model over the years so could be anything. The 'clubfoot' is like the one on your 199a. The previous one to the clubfoot and fitted to the 124, was the banana, same length but didn't have the big box on the end (or clubfoot) Front pipe is held onto the screw in collar by springs. Clutch cover is old round style, different from your 199a.

Rear hub sounds as though it is the correct one, if you look inside the hub you will see the allen heads of the bolts that hold the hub together as it is in two halves, not one casting. Can't remember if they were chromed liner or not.

The 124 type frame was first used on the series 2 model 91/92 so that frame type is not a guarantee that it is a 124. Assuming the frame and engine numbers are sill intact, that is the way to identify what you have. Removable parts can have been swapped with those from other models over the years, but from what you say it sounds like yours is a 124.

I think the one on the Haynes manual is a model 150, later style clutch cover, as your 199a and coarse fins on the cylinder and head like the 325. Been a while since I've seen the Haynes manual.

This type for frame was an improvement over the previous model as it feels taughter to ride and turns better. Engine gives really good torquey power delivery. Nice bikes.

Edited August 4, 2010 by Woody

[big john]

Front exhaust pipe is chromed, rubber joint to a separate middle silencer, rear silencer could have been fitted from any model over the years so could be anything.

Unfortunately I have to disagree on that one point Woody, the 124/125 was the first to have the one piece matt black painted front pipe welded to the centre box, with the separate banana rear box as supplied from the factory. Model 91 had the chrome pipe joined by the rubber connector which first appeared on the model 80 (Kit Campeon). Other than that all points made are correct.

John Collins, actually the Haynes manual features the 1975 Sherpa actually a UK spec. model 151 (325cc) the 250cc was 150 model. And yes the 124 model is a hard starter!

Big John

[trialsrfun]

Thank you all for the info. I had forgotten that on the 199A the model number is part of the engine & frame numbers, I will check those on the 124.

Not best pleased to learn of the starting issues though, I wonder if it could be cured by using a carb with built in choke such as the Amal Mk11/2 or maybe a Mikuni, might one of those be suitable?

[john collins]

Not worth the messing about - just keep your finger on the tickler as I described on first start from cold

[big john]

Thank you Big John it certainly does help, I am sure it is a 124 now. The exhaust is chromed with a similar but different (slimmer & smaller) exhaust to the one on my 199A, might this be the banana or clubfoot exhaust I have heard of these but have no idea which is which or what these silencers look like.

The rear hub differs from the one fitted to the 199A, it has raised, rounded strengthening ribs running across the brake drum, does that have a chrome liner. The front hub appears the same as the 199A. Carb appears to be an Amal 27mm concentric. Cylinder fins rounded and closely spaced with a screw in exhaust pipe collar. Homerlite alloy tank, seat unit is fitted.

I just happen to have a model 124 in original condition, so I know exactly what they had, from the description its a 124, they also had springs holding the exhaust to the srewed in collar. Dave at Bultaco has the springs in stock if they are missing. Rear hub is exact and had a chrome plated brake surface on the two part hub as Woody described.

As for a Mikuni, I'm sure Bultaco Uk will sort you out with one, but the fixing at the manifold would need changing as the Amal 627 is an offset/angled flange (bolted) mount, the Mikuni needs the later type rubber mount fitted.

Big John

[trialsrfun]

I now have the bike & it is a Model 124, the (matching) engine & frame numbers are 12400359. Is this an early or later model, were there any changes made throughout the production run.

The fitted exhaust is the clubfoot type (but has been chrome plated along with the swinging arm) otherwise exactly the same as the black painted one on my 199A, might this be an original fitment ?

Homerlite tank/seat unit is fitted, although carrying a few dings is far nicer than I imagined.

Any settings for the ignition, carb, best gearing for use in today's trials etc would be most welcome along with worthwhile mods.

Edited August 29, 2010 by TrialsRfun

[swooshdave]

I now have the bike & it is a Model 124, the (matching) engine & frame numbers are 12400359. Is this an early or later model, were there any changes made throughout the production run.

The fitted exhaust is the clubfoot type (but has been chrome plated along with the swinging arm) otherwise exactly the same as the black painted one on my 199A, might this be an original fitment ?

Homerlite tank/seat unit is fitted, although carrying a few dings is far nicer than I imagined.

Any settings for the ignition, carb etc would be most welcome along with worthwhile mods.

Pics?