Compared to the TY175 it will feel bigger, heavier and the engine will pull your arms out.

The bike isn't as nimble as a TY175 and won't be so easy to ride, but it is, ultimately, a more capable bike. They were aimed more at expert level riders in their day, not novices. Only you can decide which you prefer once you've ridden them back to back.

Your exhaust silencer box is a Sammy Miller aftermarket period alternative and they were used without a back box. The standard silencer was the same shape effectively but steel. As mentioned above, they had the small triangular back box from the factory but they were generally removed before the bike got used as they stifled the motor.

Going back through some old photos on my phone, I was thrilled to see the end to the pipe!!! Just hope it's still around the shop, right?!?!?

I do enjoy light and nimble, but there are days I wish it had a little more... UMPH!

That end to the pipe is not something that was ever crafted in the Bultaco factory... This is the original set up

You will come to love the Bul, properly set up, front end , rear end & tires, the bike will do the rest.

You are already ahead with the Mikuni, looks like a side main 24mm, don't let this put you off on carb

size as they came new with a 25 mm Amal,( it got lost real quick). 24 Mikuni still there pulling hard.

Still have them 92 I bought new.

Where are you located?( May have missed this)

Good luck,M 92 will reward you.

Larry

I agree with everything Woody says about this bike, and model #92 in general.

The tailpipe end appears to be an "Xdusor" spark arrestor, a US aftermarket fitment contemporary with the age of the bike.

Everybody likes to see old iron saved. But Robbie sounds young and very inexperienced. The bike is missing a lot of parts. No piston? Telltale sign of a bad bottom end. If it was a later model Bul maybe. But this is a money pit for a young person. The Dealer and everyone giving encouragement. Not me!

Best of luck Robbiesty if you take on the project. I'm in the same boat myself although at this stage for me there's no going back. I do have the advantage of good engine though. On the positive side, you have youth on your side.

Think you will have to get the hammer to the piggy bank though!

Larry.

It's an assumption to say it's a bottomless pit in terms of money. What's the objective, to make useable to ride? Or restore to as new condition? The former could possibly be done quite cheaply, the latter is the bottomless pit route, but that applies to any bike.

Aside from the piston, from what I can see, the major missing components are the front pipe, seat, kickstart and gear lever. I've seen M92 / 125 / 151 front pipes come up on ebay USA a few times, so if the original can't be found it should be able to get a replacement used item. At worst, they're available new. Kicker and gear lever are no problem. Hugh's does a seat base and a local firm could cover with foam and vinyl - not too expensive but seat is not essential to get it running.

Just because the piston has been removed doesn't mean the bottom end is trashed. It could have been something like a snagged ring that caused it's removal, or a mild heat seizure. The cylinder liner should give clues. Mains and big end condition can be gauged by spinning the motor and listening for dry or scored bearings. Mains can be checked for vertical movement in the crank, big end checked for play in the crank. The bottom end of the motor could be quite sound.

If so, a new piston is the biggest single expenditure to try and get it running at about $180? Plus the rebore. I don't know if that's expensive to you guys or not. The gamble is, spending that much and then finding that despite the bottom end checks, it does turn out to have unacceptable wear when running.

If the bottom end is shot it's another $350 - 400 for a complete rebuild? So something like $600 to sort the engine worst case. Plus some used parts. So for $600 and a bit you could have a useable runner but whether it's worth it depends upon what you want to do with it. If you keep it you just absorb the cost as with any bike. If you come to sell it you have to consider that outlay plus what you paid for it and whether you could at least break even. I don't know what those bikes fetch in the US.And whatever the bike cost to buy.

In the end, although it's just an old dirt bike, it's a Bultaco and in the history of trials they have a bit of 'provenance' and status, probably moreso than any other marque. And if you want more oomph than the TY, this will certainly give it you. The TY will be far easier to ride, but it's not a 'taco....

One of my favourite models they look beautiful with that "kit campione" tank seat unit

Must say Woody that's a pretty good analysis of how to go.

Larry.

What an enjoyable thread, some really good advice & knowledge from many folks.

Larry

I really apprecaite all the good words, and even some reality checks too! Going to take a look at it again tomorrow, now armed with some great knowledge. Like REALLY looking at the crank. Thanks for the advice!!!

And for today's update:

Found the pipe in the back of the shop, along with some small pieces. Still missing stuff, but better than nothing, right?!?!?

The cylinder looked like a hone would work, and measured at 83.72. Is that aready bored or close to original?

The rod was nice and tight in all directions! And it turns with ease and no noticable sounds.

Might be buying a Haynes repair book just to get me going, and hope to find a seat and kicker cheaper than new.

But still not (yet) in my shop. Still working on a price!

Thanks again for all the great input!!!

Edited January 13, 201511 yr by robbiesty175

The Bultaco finally escaped from the bike shop and wound up in my shop!!! I am so excited, but lots of work ahead...

Discovered when you tear apart a motorcycle, they really don't take up much room, so maybe I can fit a few more in my little work area. But for now, cleaning and making a list of parts to hunt. And spent yesterday with the buffer. This will be a very shiny bike! Getting help for folks in this group has been a great help. Keep the advice coming!

I will keep you posted!!!

looks like your doing a nice job mate what you plan on doing with the engine full rebuild? my 199A is in progress. Have fun

abit off bling.