peterb

Hi Orange, Need more info to sort out. Did this suddenly start, was it something that steadily got worse? It does sound as though the carb is running rich, have you checked all the carb settings as posted? Do you have vent hoses fitted to the carb that are connected together and not to atmosphere? Is the air filter dirty. Does the bike smoke excessively? If blue smoke, it could be a failed oil seal allowing gearbox oil into the crank case. Bye, PeterB.

Hi Jon, I just had a thought, do you mean "avoir du poids" for advp? That would be French for "to be weight" Bye, PeterB.

C'mon Jon, Now you got me thinking, advp pounds?? - ok I know it is pounds mass but advp I don't know, how about an explanation. From another Island where we drive on the "wrong" side but use Kilos. Bye, PeterB.

Hi Scotty, The chain length for the 270 is 100 links. Don't buy a cheap chain, get a good one, most Japanese chains last well (DID, Tsubaki), also Renthal sell good chains. Bye, PeterB.

Hi Martin, There were piston centralising spacers fitted to the Bultaco's and it may be that later pattern pistons are not supplied with any. I haven't seen any fitted to more modern 2 stroke motors over the years and would be inclined to say that the piston will centralise itself when assembled in the barrel, so proceed as plan B. Bye, PeterB.

Hi Jan, BPR5ES is fine for the Raga, I usually gap my plugs at 25 to 30 thou, approx 0.6 to 0.7mm. Donnie, Gas Gas usually supply their bikes with the carbs set up a bit on the rich side, if you have a DellOrto then try a 115 main jet in place of a standard 118, don't know the standard pilot jet but 33-35 should be fine, pilot screw out 3 to 4.5 turns as a starting point. Screwing out richens the mixture. Needle should be D36, 2nd clip from bottom. Try tipping the bike over to the left before starting from cold as this floods the carb and makes things easier to start. Ta ta, PeterB.

Looks quite good really, the frame very much like a GG. Not so easy to comment on as it is a computer generated image so hard to say if the real bike will end up like this or not. The carb hose is shown connecting up to the underneath of where the tank used to be, at the back so it would be a relatively short run. Wonder where the access is to refuel the tank. The fuel pump should not be much of a reliability problem, DellOrto make a vacuum operated fuel pump which is specd on another bike. I like the idea of the air filter up high and away from the rear wheel, given me an idea for the next project bike. Bye, PeterB.

Hello APK, If you are talking about the rear caliper bleed nipple, this thread is M6 x 1.0 (6mm diameter, 1mm pitch) The pre PRO models have a larger nipple arrangement. If it has seized in place, be real careful when drilling out that you are precise in getting your 5mm tapping drill exactly in the centre, also you need to know how deep to go as the end of the nipple has a bevel surface that seats up against a similar bevel inside the caliper. Best to measure the new nipple first to gauge the drill depth so as not to cut past the origina bevel in the caliper. Bye, PeterB.

Hello Gordon, It may be due to a partially blocked petrol tap, petrol cap vent not working, fuel filter clogged in the DellOrto carb, throttle slide sticking, or maybe you have vent pipes on the carb vents that are connected together and not venting to atmosphere. Does sound like mag side oil seal though you say the motor is fine for a while after the carb is cleaned out, have a check on the above. Bye, PeterB.

Hola Greeves, Great pictures, Sunny, well done. I hope you get enough snow free months to ride a few events. In 1972 I bought a 1970 Bultaco 250, not sure of the model number but it had a separate tank and seat with the silencer exiting the exhaust pipe up under the tank. I thought this motor pulled very well, and would rev out well too. It was, like Big John's bike, my first full time trials bike, we used to ride our bikes to the trials then, carrying petrol in a back pack to get home as the petrol stations were closed on a Sunday in Yorkshire back then - bit different now! Bye, PeterB.

Hello Loomesy, All what Dan said is fine though I must point out that your carb is a PHBH, not the later model PHBL that has an adjustment as per Dan's description. The PHBH carb uses air as the pilot circuit and the screw adjustment at the rear of the carb body, should be around 1 to 1.5 turns out as a starting point, from fully clock wise. Turning this adjustment out, counter clock wise, leans off the mixture at the low end. Ta ta, PeterB.

Hi Joandemma, The seal has a spring to tension the seal lip, it is the open side of the seal, this side should face the pressure area, in this case, it would be the crank case. Also, the teflon seal usually has a steel outer casing, the closed part of the casing goes into the housing first. It's not an easy seal to fit and it is easy to damage the steel case when fitting. I turned up a steel mandrel to mount the seal onto to allow the seal to be fitted squarely into the housing. Bye, PeterB.

Hi kluson, Gas Gas call their latest bikes a TXT PRO, this new model released in 2002 had a number of teething problems, better models were sorted out in 2004, the 250 is fine. Earlier, pre 02 Gas Gas were also called TXT but not TXT PRO. These have a very well sorted, more chunky motor, the 2001 TXT 321 is especially suited for trail riding and blasts in the hills, as well as being very useful in trials though certainly not as powerful or as light as the later PRO models. Bye, PeterB.

Hi Ian, From memory the 01 shock is 300mm centre to centre - check the original. Best place up north for a shock rebuild is White Brothers in Darlington, ask for Al. Ta ta, PeterB.

Hi Hensley, Try the USA GG parts importers, not sure but I think their website is gas gas parts usa.com, or try looking for Rising Sun Imports (Both the same company) - google them both. Bye, PeterB.

Hi joandemma, These bearings usually last for many years, unless water finds its way in. Are you sure the water pump shaft/seal is not passing coolant? The water settles in the well of the bearing while the bike sits for a week or two and corrodes the bearing surfaces. Similarly, any water egress from drowning the motor and not cleaning out immediately gives the same results. Never heard of the GG crank being out of balance. Are you sure the LHS drain hole in the bearing/crank case is aligned properly? Is the LHS teflon oil seal in the right way around? Bye, PeterB.

Hi Mike, There is not much room to slot the holes in the pick up sensor, but enough to give a range of 1 to 3mm or adjustment, I set mine up between 1-2mm static advance to give a little more go through the rev range - biggest increase in power was fitting the crankcase padding, lose a bit of smoothness is power delivery though. Bye, PeterB.

Hi kimpy, I wonder if you are in the Waikato or BOP area and want to ride the air cooled series? I never liked the 310 Mont, the Fantic 305 was a good bike with useable power and ok suspension which you could easily use in modern trials in the clubman/Inters route. Best model is with the right way round forks, the upside down forks were a pain in the neck to work on. Spares are a problem here, ok in the UK but I think pistons are pretty rare. The Honda TLM 220 is a heavy bike, about 95kg, and also not so easy to get parts for - but, would be very reliable and pretty gutless by all accounts. I have a 220 in the workshop awaiting time to turn into something different, not sure what yet. Another good option is an air cooled 250 Gas Gas, great bike and lots of parts available in NZ. Has front and rear discs, mono shock and not too heavy at approx 84kg. Bye, PeterB.

Hi Scotty, You need an 11T. Don't know where you live, if up north of UK, try White Bros, South try BVM, for parts and 520 DID HD chain. Bye, PeterB.

Hi Jan, I used to ride a 2004 200 in the Nationals here, all standard except I fitted the plastic crank case padding from the 125 motor - your bike already has this fitted, leave it in as it makes the motor more punchy, doesn't grip so well but stacks more fun to ride. (the standard 200 motor does not have the padding fitted) I experimented with a small flywheel weight but thought the bike was fine without. The 125 and 200 cylinders are interchangeable. The DellOrto jetting on the 200/125 is ok standard, the motor is very sensetive to any jetting changes, leave the D36 needle in. Move the pick up sensor clockwise (slot the sensor holes) slightly to achieve a slight static ign advance. Bye, PeterB.

Hi Jan, Yes, the bearing seals usually sit flush with the bearing outer face. A friend tried the fit of a commercially available seal that is 1mm wider than the GG unit and this does stick out from the bearing - approx 1mm - it looked as though it may have done the job but we did not try this out - too much time to lose! Happy trialing! PeterB.

Hello Jeeves, After draining, re-fill the gearbox with 700ml 10 weight mineral oil only, or an ATF rated to Dexron III. From your description, sounds as though the pilot jet and passage ways are choked. Strip carb and thoroughly clean out, remove the jet and the adjusting screw and blow everything clear, firstly, count how far the screw is out from fully in, it should be around 3 to 4 turns out. Going anti clockwise richens the mixture. Bye, PeterB.

Hi Jan, The crank should almost be a push fit into the bearings, not so tight like an interference fit with the newer bearings. With heat on the bearing housings and the bearings in the freezer, they should just drop into position. Well, maybe the bearings do stick out a mm or so, can't say for definate - you'll find out soon enough if it is ok! Bye, PeterB.

Hi Jan, Good luck! The sleeves should pull off the crank shaft, if tight then try levering very gently with a fine screw driver, if still too tight then use a hot air gun to heat up the sleeve and prise off. The bearing oil seals have the spring that tensions the sealing lip facing into the pressure area (open side facing the crank case, closed side is face down into the bearing when fitting) Bye, PeterB.

Hi Jan, Here is a possible solution for you. It may be that you have the later type bearings while still keeping the sleeves on the crank shaft. The 05/06 bearings (can't remember the changeover year for the new main bearings) require three seals each, an O ring seal on the inner groove of the bearing, an O ring seal on the outer groove on the bearing and a specific oil seal to fit on the inside of the bearing. This seal is a specific Gas Gas seal though there is a commercially available unit that is 1mm wider and seems as though it would work - though I have not tried this myself. Note that the crankcase LHS housing has an oil drain hole that is drilled out to lead into the drain plug area, this is to allow gearbox oil to feed via capillary action from the top of the bearing and exit to the bottom and out into the gearbox area. When you fit this LHS bearing, make a mark on the crankcase with a felt pen, where the drain hole is, and the corressponding hole on the bearing. Heat up the case with a hot air gun while freezing the bearing, complete with 3 seals in the freezer. Line up the marks for the oil drain and let the bearing drop into the housing. You can leave out the sleeves with the newer type bearings but remember the 3 seals per bearing and the LHS teflon oil seal - difficult to fit squarely - best to use a drift turned up from scrap. Should be ok after that. Bye, PeterB.