feetupfun

If you are asking about present-day popularity then yes, probably the small number of Whitehawks made is why there are not many seen nowadays. I think the reason why there were much fewer Whitehawks made is because there were no Whitehawks made for the 250 motor. If you look at the relative popularity of the smaller Majestys to the 250/320 Majesty back in the day, the 250/320 seems to have been way more popular than the 175 Majesty and 175 Mini Majesty. I think that this would have meant that Whitehawks, which were only made for the TY175 and TY80 motors, would not have been a popular choice for adults. As for one being better than the other, Whitehawk frames have a visual advantage, having nicely brazed joints, compared with the MIG welded Godden Majesty and the Yamaha-based frames. Then again, the three Majesty designs that use the TY175 motor all have longer rear wheel travel than the two Whitehawk designs that fit the TY175 motor.

Yes as JC says, I think the spacer that fits against the brake drum side wheel bearing is a different length. No big issue but watch out for it

If you mean the white wonder 349, it is quite a good bike and a better thing than the first model (red) 349, which I would have called the 1979 model, mainly due to the white wonder having a shorter wheelbase. Both 349s are quite different to ride when compared with a late model 325 Sherpa T and a lot of why people like one and hate the other can be attributed to personal taste. The Montesa has an absolute killer motor but to me feels like it takes more effort to ride (compared to the Bultaco, and the 348 Cota). A lot can be done to either bike to make it behave any way you want and so yes, to compare a standard 349 with a Puma Bultaco is not very fair. Seeing you asked specifically, I would say that as far as standard bikes go, the Bultaco 325 would be the easier to ride of the two, and a 250 (238) Bultaco is easier again to ride for an intermediate level rider.

the wheels are the same so yes a TY175 wheel will fit a TY250 swingarm The swingarms are different and are not interchangable. Probably the most important difference for interchangability is the difference in width at the pivot. They are also different lengths.

floppy gear shift action kickstart lever cracked at knuckle play in kickstart knuckle kickstart not returning kickstart not staying in retracted position hole in clutch case from kickstart spline clamp screw head impact holes in magneto cover frame damage - cracks, bends, twists rusty fuel tank internals damaged exhaust header rust pitted fork tubes

EP oil in the clutch case will reduce the friction available between the clutch plates, and not advised to use it in the gearbox either, in case some gearbox oil leaks into the clutch case

This is a B model bottom end. I looked at an A model as well and it looked very similar

http://bikepics.com/pictures/646837/

I bought a TY175 once that had a Gunnar Gasser twistgrip (huge cable pulley diameter) fitted which made it about 1/8th turn from closed to open on that carby. It worked fine. Maybe on a more zippy trials motor it might have been a problem. It's also possible that you can train your mind and body to ride with just about any setup.

if you can post up photos of the bike it may help with suggestions

It may also just be the spring is weak and the shaft needs relubing. Either way it is a 2 minute job and springs are readily available

I use a multimeter for this and watch for a voltage spike in the LT wire

what's an LT spark?

The two different 125 Scorpa four strokes sold here (concurrently) had different forks. One of them had the same forks as the SY250 while the other had something not quite as flash - non-adjustable perhaps. There was a difference in the seat department too, one had a seat the other not. Other things like alloy rear sprocket vs steel also spring to mind.

I know that some people modify their TY airbox by removing the lid and fitting a flat piece of foam across the top instead of the foam sock-on-core that is standard. One weakness with this is that the velocity (and pressure drop) of the air through the foam is increased by the reduction in surface area of the media. Another consideration is that the smaller a filter is, the quicker it becomes clogged with dust, in dry conditions (very important where I ride). The modern trials bike filter in Woody's Majesty photos is a basin shape which increases the surface area compared with a flat piece of foam

Patrik, there are some errors in your explanation. I noticed the following straight up and stopped checking the rest: 175cc is 0.175 litres, not 0.0175 litres 2.3 m/sec is 8.3 km/h, not 83 km/h I also think that the proof of the design of the TY175 airbox lies in the fact that the standard competition version of the TY175 has a wonderful free-revving characteristic. From what I understand of what you are saying about your bike, there is a rubber snorkel on the airbox. Please be aware that the standard competition TY175 as sold around the world as model 525-xxxxxxxx, did not come with that snorkel, but road-going Ty175 models such as the 1N4-xxxx did have the snorkel, and the snorkel probably does cause a bit of additional drag to the airstream.

probably depends which majesty tank you are talking about and which TY frame. There are quite a few different majesty tanks

Riding with peeling chrome will not make the hub irrepairable, it will just have poor braking and will chew up the shoes faster than a good drum would. Just inspect the shoes for thickness after each trial to avoid going metal to metal

The ball is the same diameter as the rod whatever that is (5mm maybe). You can file or grind the face of the cam flat again, just make sure it ends up smooth where the rod end contacts. I've successfully built worn ones up with mild steel weld and machined the OD back to size when the pit in the cam was too deep. I don't think the cam face needs to be especially hard, but smooth is important

modern trials bikes overheat if you flog them along a road. the cooling system is only made to cope with intermittent high load operation.

You can generally run a lower preload on the clutch springs with the plates that have friction material, so you can achieve a lower lever pressure without any slippage. In my experience they are only a real benefit in a 325cc motor, because the 238 and 250 motors can be set up with a nice light lever pressure even with all steel plates and not slip.

I think naichuff is saying that a Bultaco will run backwards even with the timing set quite a way before TDC. I agree with this and add that advancing the timing can increase the tendency for the motor to run backwards, because at very low RPM (when kicking over, or when motor on verge of stalling), the motor is more easily be stopped and reversed because it fires with the piston further before the top of the stroke. A different factor that can muddy the waters in discussions is that the motor will run better in reverse the more retarded the timing is. Some bikes have a diode in the primary circuit to prevent ignition when the motor is rotating backwards

In case you are wondering why it is OK to have no retaining circlips, it is just that the internal pressure when the forks are compressed is not enough to cause them to slide upwards. Some Bultaco forks have vented caps, which limits this pressure, but the odd thing is that there are many Bultaco forks without vented caps and also without circlips. A bit of a mystery so far to me. Anyway, I run (non-standard) unvented caps on my 1968 M49 (the bike in my avatar) and do not use circlips and despite quite a hammering, the seals have stayed put.

I did mine similar to Guy's

The SM kits I have seen do not require removal of the original mounts