woody

The 92 has a lot of raw power and pulls like a train. It isn't more aggressive than later bikes but it is a lot harsher in feel with more vibration,later motors are smoother. The 159 is aggressive due to the light crank weight. As the 183 and 191 are virtually the same bike I'd guess they are too but never ridden one of those.

I use a 28mm on the 325/340 engines that had a 28mm Bing originally. Mikunis work fine if you can jet them but they are a pain in the a*** to jet (for me) If it isn't jetted right when it comes it's a lottery what to change if it's the mid range that's out due to the endless needle / needle jet combinations they have. I've found the OKO is almost right as it comes on virtually everything I've fitted it to and just needs minor change to pilot and needle position. If both are jetted right then I doubt either is better than the other - apart from the price This is the one I use http://www.ebay.co.uk/itm/OKO-28mm-RACING-CARB-FLAT-SLIDE-CARBURETTOR-CARBURETOR-/301495710655?hash=item46328b73bf and one of these http://www.ebay.co.uk/itm/SET-10x-SLOW-JETS-Tuning-PWK-Arreche-OKO-Carbs-LOW-SCTZ-/262647291462?hash=item3d26ff9e46

I'm being perfectly honest when I say I can't tell any difference between a 199, 199a or 199b power delivery. The 159 I had was much more aggressive than any of those - due to the Pursang type weight on the clutch

They run virtually out of the box on any bike. Generally the most you have to do is alter the pilot and move the needle one notch, can't remember which way or what pilot I've used (somewhere around 45 maybe) but it may be in the forum somewhere. A box of pilot jets is pretty cheap in the 32 - 50 range which you could order with the carb.

The clutches can be a bit finicky to set up as people try for a light pull on the lever which can lead to them slipping. All you had to do (I appreciate you wouldn't have known) was take the cover off and wind the adjusting nuts in one turn which would probably have sorted it. The other thing to check first though, is that the arm isn't sticking in the timing cover. This can happen if a bit of grit or grime has got in there and when you release the lever, the arm doesn't fully return meaning the clutch hasn't fully engaged. It's not apparent that this is happening when it does. To confirm, pull and release the clutch lever, then reach down and see if you can push the arm further back. If you can it's sticking and you just need to remove it and clean the housing out so it moves freely. If it isn't sticking just adjust the clutch spring tension as mentioned previously If you search this forum for clutch set up there is plenty written on how to do it from scratch. Also, when starting a Bultaco get the kickstart to the point where it engages and push hard, don't kick or thrash at it. The clutch can slip on the kickstart but that is ok as it won't when riding but you need to get the right starting technique to avoid it slipping on the kickstart

Scooter Assassins in Taiwan sell genuine OKO for around £60 and free post

11/39 is standard gearing but it is a bit high (for me) I run 11/42 or 43 which is about the same as 10/39. But you can't get a 10 tooth front sprocket here

To fit the triangular head steady you also need the T bracket that bolts to the head and these are a different size for 250/350 because of stud spacing

As long as you've released the bleed nipple enough it should back bleed with a syringe no problem. I did one a couple of weeks ago. Messy job though. If you have one of those alloy bleed nipple/banjos, I'd recommend you junk it for a proper steel one as the banjo sheared off on mine as soon as soon as I tightened the nipple

Ignition side or clutch? Any ignition flywheel will swap as long as it's from a Sherpa. Pursang looks the same but won't work as I've tried one, I think it was the timing that was different but a long time ago now. Clutch flywheels are different shapes and some may foul the inside of the later 199 style casing, get one from a 250 that has the same casing to be sure. Some models had the really light, thin clutch weight, an M159 motor I have has one

You could well be right Stan, I'd assumed, probably incorrectly now you mention it and reading the post again... that it was the little barrel he meant wasn't touching the pushrod

Might sound daft but make sure you have the cam on the right way around, should be evident from the contact marks - also make sure it isn't bent or mis-shapen (unlikely) Or: A ball bearing sits between the two pushrods - sounds like it's missing With the timing cover off, pull out the pushrod, then prise out the pushrod seal as there is a gap behind the seal that the ball bearing may have previously fallen into if someone has tried to feed it in with the seal in place. If you feed the ball bearing in from that side you need the seal out to ensure it has actually gone into the pushrod housing. Worth a look before you search for another to fit if it is missing

The jubilee clip is a 'user fix'... You just clamp a jubilee clip to the shaft spline on the right side of the engine to stop the shaft sliding to the left.

Fit Barnett friction plates, they don't stick. And because they are higher friction, the springs can be backed off a bit to help lighten the clutch pull. As mentioned in the first reply, the gear shaft can slide sideways slightly to the left meaning that the selector forks lose contact with the drum. Tap the end of the shaft to make sure it is fully home. Inside the clutch casing there is a circlip on the gear shaft and sitting against that on its outer side is a wave washer and shim. I'm not sure if this is supposed to stop the shaft disengaging from the drum as the washer should sit against the inside of the clutch case, but I don't think it does as it still seems to be able to move a little. Without it, it moves a lot more. A jubilee clip on the other end, as mentioned in previous post, stops movement. If this isn't the cause of the problem, it is a strip down as the selector mechanism is inside the cases. Possible causes are incorrect shimming, weak spring on the selector fork, worn or broken tips on the selector fork etc.

The bolt on peg relocation kit is from TY Offroad here in the UK who has been specialising in Honda TLR rebuilds and modifications for a good number of years now. Lots of Honda parts. http://www.tyoffroad.co.uk/

Had a quick look at my stripped engine this morning. The O ring on the sprocket side is seated 7mm inside the casing, that's measured to the inside edge of the O ring housing / groove. As you can only move the shaft by 5mm, even if you could cut it off flush with the casing, you still couldn't slide it far enough to clear the O ring. With the engine apart and the shaft out, you may be able to remove enough to enable it to slide far enough to get at the O ring with the engine assembled, but there would only be 2 to 3mm left of the shaft extending past the O ring and I wouldn't know if this would compromise the sealing effect.

Has yours got the 30mm diameter final drive gear? Some 340s had final drive gears fitted that were 30mm diameter instead of the more common 25mm which the 5 speeds also used. Therefore there are two sizes for top hat sleeve, seal and sprocket I'm only guessing, as I've never had one with a 30mm diameter, but the smaller diameter final drive gear could possibly be used by changing the final drive bearing to suit as well - but it is only an assumption

That's what I think could maybe be modified to enable the 5 speed gear to fit the 340. Machine the recess into it

Out of interest, as I don't need one, where did you buy them from?

Don't lose that shim off the layshaft gear...

The 5 speed final drive has the same number of teeth but is machined slightly different. I'm no engineer but would think it possible to modify the 5 speed to fit if you can't find original. That was my plan B if I couldn't get an original when mine broke.

I was going to offer that as a possible solution to avoid splitting the cases but I'm not absolutely certain there would be enough clearance, so didn't... When I'm back in the shed at the weekend I can try and measure up against a part dismantled engine, see if I can get a definite answer

Although you can push the shaft through from the sprocket side, it won't go through far enough to clear the O ring. As above post, you have to split the cases to replace that one. I wouldn't split them unless absolutely necessary

I don't think there is an answer to that as if I remember correctly, the people that helped Shirty build them have said no records were kept. One of them, Sam, has been on here from time to time, so he would be the one that may have an idea

Are you sure it's 10 on the front? 10:46 is very low geared, 11:46 is the usual gearing. A 10 tooth Bultaco front sprocket was never commonly available, they aren't available any more