motovita

I have that setup. Have you been able to stretch the airbox hose enough to secure it to the carb? Mine comes up a bit short, I wonder if my air filter hose is shorter than current production, it may be an original Bultaco 199B part.

A longer screw won't help, the tip of the screw contacts the carb body in the venturi and stops. I was able to remove a small amount of metal where the screw makes contact and get nearly one more turn on the screw. I'll try that and see how it works.

I'd like to hear from anyone who's fitted a Mikuni to a late model Sherpa T as to how they did it. I took some measurements and found that the Mikuni is to short to span between the rubber intake and airbox boots. The necessary cylinder boot is stepped to two different diameters so I can't simply fit a longer hose, and the airbox boot is flanged at the airbox end so again not a simple hose swap. The carbs are readily available and affordable but I haven't found anyone who offers a ready to install kit.

The carb slide in my 199A is badly peened where it contacts the idle speed screw, I can't elevate the slide enough for a strong idle before the idle screw bottoms out in the carb body. I haven't found a new slide here in the USA and I'm not sure I can get one from the UK in time for the next meet. The slide is in good shape other than the contact spot with the idle screw. Has anyone repaired a slide like mine? I'm thinking I could thread a small brass screw into the slide to give a new surface for the idle screw to contact would give me back my idle adjustment. I'm guessing the slide might be plated zinc, or somesuch metal. Does anyone have any suggestions for me, or a US source for a new slide? I'll also be looking into a replacement carb, I want to stay somewhat period correct so I don't want an OKO or similar flat slide.

I am similarly afflicted. You need to keep trying different brands of helmet until you find one that fits. In extreme cases you could alter the foam liner of the helmet a bit, which will defeat some of the helmets protective abilities.

Is it fixed yet?

The effort and akwardness of repeatedly kick starting a Trials bike, frequently on uneven terrain, is a significant concern to a gimpy old man like myself as well, even though yes I can start it with my hand if I want to. By the way I think I recall seeing the bleed hole in snowmobile cylinders as well.

Maybe not even a battery. https://www.ski-doo.com/technologies/shot.html Bring it on! I've ordered a TRS in the mean time.

USFS approval is not the standard in Washington. It does need to be marked as a spark arrestor though. My later model is marked in tiny letters that are hard to see. Assuming you have the original system you might look it over closely, otherwise it's going to take some fabrication.

Any newer input on this question?

It looks like a very nice bike. I'm sure there's quite a story behind it.

Start in the lowest class and work your way up to find your level. If you start in too high a class you might miss some of the basic skills that are the foundation of moto skills.

When I park my Bultaco for a week or two I turn off the tap and run most of the fuel out of the float bowl, if the bike will be parked for a longer time I remove and drain the float bowl. Minimizing the time the float has to sit in the swill that passes for gasoline these days will help it live long and prosper.

The float I used was from my 94 R100 GS and was identical to the original float. In the U.S. BMWs came with 32mm carbs, in other markets 40mm carbs were standard, I don't know if they use the same float so you might double check that. In the U.S. I've found BMW dealers to be a good, and the least expensive, source for Bing parts.

Replace the float, it's the same one used in the 32mm Bings on BMW airheads and is available and inexpensive. I've been running a used BMW float for a few years but I think it might be time to buy a new one. I can't fault the logic that the best repair for a Bing is to replace it with a Mikuni though.

Here's one. https://amsracing.com/product/1968-0-bultaco-pursang-model-68-mkiv#prettyPhoto

I use that in my saws, other than the expense I would have no problem using it my bikes. Bel Ray makes Husky oil.

Here's what I use. http://www.belray.com/bel-ray-mc-1-racing-full-synthetic-2t-engine-oil I've been using it since it was a new product.

Snowmobiles had it a few years before that, since 97 if I remember correctly.

Did your "carb clean" include removing every removable part and cleaning all passages? If not do it over.

The 74/75 models had lighter flywheels, I ran one on my 77 model. I don't think it helped my scores but it made the bike more fun to ride. Get your bike in good working order before making any changes though.

I suggest buying a Domino Trials throttle with a new cable, not expensive and will give you a fresh start. Get some Trials grips while you're at it.

Last I checked Tublisss did not offer a system for 1.85 rim, has that changed? Feetupfun, if there's no photo of the modified rim can you post a sketch of what you did? I can't picture it.

I was considering sealed caps to slow fork compression on hard drops where the fork bottoms out. I found that I could buy new springs for less than new caps, my springs appear to be original with added PVC spacers so I decided to go that route. I decided to try shortening my springs first. I cut 50mm off of one spring and added 45mm of PVC spacer in it's place with good result. My 199A fork still has good compliance on the small stuff and steers well but is a little more stable on steep, sudden, drops, where it still bottoms out. I may play with the other spring later but I'll ride it as it is for a while first.

Have you ever experienced pressure build up beyond what you wanted, or do you have manual vents on your caps? I see Bultaco UK sells a pair with Schraeder valves.