peterb

Hi Darell, Regarding your TY250 clutch basket prong breaking off - you may be able to repair this. I've done a few baskets on other bikes in the past. Usually the prong breaks off almost flush with the rear of the basket. Carefully mark the prong hole centre on the basket and drill out the basket for either a 4mm or 6mm clearence hole - I don't know the ID of the thread of the TY prong - most likely 6mm. Countersink the basket hole at the rear and then drill and tap out the bottom of the prong to 6mm. (Sometimes you can continue the thread from the top of the prong) Use a countersunk allen screw with loctite and attach the prong back to the case. Job done. Usually last well with no problems. Bye, PeterB.

Hello there, I just saw this post, almost a year too late! Tim is now settled a mile away from my place in Auckland and managed a few trials on my tweaked 352cc Bultaco - without any damage! There is a bril trials scene here - I'm from North Yorkshire from the late 70's and have ridden trials here since. Check out www.nztrials.com has a few scenic videos from here, I think Tim is on one of them as a spectator as I blagged the Bult for that event when the B40 expired before the start. As in most parts of the World, trials riders here are the most friendliest and helpful types you could ever meet. We have a bril North Island National series, held over 6 weekends of 2 day events in various centres catering for 7 grades of riders over 4 different lines. You cam always contact me if you have any questions about NZ and trials here, could also help out with riders wanting to perhaps emigrate here - it's a great country, lots of space, brilliant trials scene, little beauracracy and decent weather. Bye, PeterB.

Hi there, Best person to help here would be Jim Snell, try his Gas Gas USA website (Trials Parts) and have a good search. Don't recall hearing about a different flywheel, only a carb mod to improve low end pull. I called in at Llangollen in 2000 on the way to watch Dougie win at Hawkstone, nice village. Bye, PeterB.

Hello Glenn, I haven't needed to buy tubes for years so my old ones are all 4.00 x 18 (4 inches wide by 18 inches diameter). The newer figure you have of 110/90 x18 is the metric equivalent. Divide the metric millimetre figure by 25.4 (1 inch = 25.4mm) so that 110 becomes 4.33 inches wide with a 90% margin as far as I can make out. Maybe then the 90% equates to a usable range of 3.897 ins to 4.33 ins. A 2.75 x 21 inch tube would therefore be 2.75 x 25.4mm = 70mm wide, or 70 x 21 in metric terms. Bye, PeterB.

Hi Scotty, Sounds to me very much like the magneto side crank case seal is leaking. Take off the magneto, mark the backplate to re-set the ign, remove the backplate and woodruff key and undo the 6 bolts that hold on the seal retaining plate. Also, there is either an O ring seal or a paper gasket on the seal housing, not sure on the 71 model. Renew housing seal, fit new oil seal, seal spring facing in toward the crankcase and re-fit using grease on the seal lip. If the seal was passing, you usually find an oil mist around the seal housing outer area. Good luck, PeterB.

Hello GGB, The earlier TXT50's were supplied without a fan, fitting one is a good idea. Measure the plain steel clutch plates for thickness, one should be 2mm, the other 2 are thinner, 1.5mm I think. Order a new 2mm plate, P/N MIT50032064 and replace one of the two thinner plates. The clutch will take up at lower revs. This mod works well. Bye, PeterB.

Hello Graham, The plastic piece is a spring guide that fits inside the slave spring inside the clutch casing, larger diameter on the plastic goes into the case first. Use an ATF rated to Dexron III, 500ml to refill. Bye, PeterB.

Hi Spike, If it is an 06 PRO then you need 550ml oil, about 50ml stays in the box when draining so you would be fine with 500ml. Always use a mineral oil in the box, never synthetic. 10 weight mineral or an ATF rated to Dexron III is fine. We always leave the forks set up as they come out of the crate so unable to help you with any adjustment set up. Fit a 10T gearbox sprocket and use a water proof grease on the linkage bearings. Bye, PeterB.

Hello there, I used to ride new 325's in the North East (UK) in the late 70's, and still have a Sherpa now. In all of these bikes I fitted 25mm long nylon spacers on top of the standard fork springs. Turn them down so there is a spigot fitting into the spring and a matching taper for the fork cap. Bye, PeterB.

Hello dom1, What country are you from? Is your bike a 250 or 325 - Below applies to both capacities. Best mod to do is to fit a decent carb. I use a DellOrto PHBL 26 BS straight off a modern 250-280-300 Gas Gas. Fit a 95 main jet and the rest of the jets/needle are fine as they are. (D36 needle, second notch off the bottom, 270K needle jet, 30 pilot, 60 slide). It should fit straight on to the existing rubbers. At this stage you can also fit a new Domino throttle assy with a GG t'cable. Set ign points at 15 thou, I usually set the ign timing a bit advanced, around 3 to 3.5mm BTDC. 5 1/2 inch Renthals. The aluminium rear wheel axle from a Gasser goes straight in and saves a bit of weight, also I use the larger eccentric Raga chain cams. Have fitted the Alpina (not sure if this was sold in the UK - it's a trail bike version with wider spaced gear ratios) front wheel as it has a much larger front brake and ideal for nose wheelies - needs a bit of fettling to fit in. Machine up two 25mm long nylon spacers for the top of the fork springs, they always felt saggy, even from new. This should keep you busy for this weekend. Bye, PeterB.

Hello John, I fitted brackets to my 1978 Sherpa (198 model?) to take those stainless Gas Gas footrests. Best to get the brackets as far back as possible and as practically low as possible. Even with the rests low and back, they still feel too high and too far forward when compared to a modern bike. Bye, Peter.

Hello Floored, The O rings come dry. You can assemble with a little grease. Sorry but I don't know the torque figures. The head does not usually warp. Check the fan is working properly, they normally blow like a good hair dryer. (Not that I use one!) The other problem area is the thermoswitch, they cut in around 80C - you can check the operation in a cup with boiling water and an ohm meter (DVM) - in boiling water the switch should close in approx 10 to 20 seconds. If your ignition system is Ducati, there could be another problem - there is an electronic unit under the tank that provides the ignition curve and the AC to DC rectification for the fan - if the thermoswitch and fan check out ok and the fan still does not turn on when the motor is getting hot, then this module has failed. Check to see you are not losing water into the gearbox via the water pump seal. Good luck, Peter.

Hi Bert, Are you sure that you moved the stator plate ANTI clockwise from the original mark (To the left)? If you are happy with the ignition timing then leave it where it is. The standard clip setting on the D36 needle is the second clip position from the bottom, which is fine in most cases. The lowest position would give the most fuel rich condition. You can tune in the low end carburation with the pilot screw, which on this carb works on the fuel, not the air so that turning in the screw weakens the mixture (less fuel). Start with this screw turned fully in then unscrew 4 and a half turns and adjust from this point till it feels good for you. Bye, Peter.

Hello Fuzzy, I have had a few 325cc Bultacos over many years. They don't usually rev out that well at the top end and gobs of low end power is the norm. With various carbs, the main jets that have worked best have been around 1.00mm diameter - 95 to 105. The Mikuni should be approx 26mm but I am not aware of the needle jet size. I have tried a 26mm Mikuni from a Kawasaki KT250 which was ok, a 26mm Dell Orto as supplied for a new model Gas Gas, the only change needed was for a 95 main jet. This worked very well. Better still was a Keihin 28mm flat slide as fitted to a Raga Gas Gas 300 that has standard jets/GJH needle and just needed a smaller main jet - made a 100 using a soldered jet drilled out to 1.00mm. This gave the best power spread - and revved out to the max. I'd say your bike could be set up too rich - can you give the throttle needle type, needle valve and pilot jet sizes. Any idea what bike the carb came from? Is your ignition timing set correctly? You don't say what happens at the top end - is it starving for fuel or running too rich and four stroking? I don't know about the s/arm, could be a home made one. I can't help with the shocks either, I am sure someone else has some knowledge here.

Hello Bert, Yes you have to remove the flywheel to get to the stator plate. You also need a specific flywheel puller to remove the flywheel. The centre nut is a conventional right hand thread. Be sure to locate the crank woodruff key correctly when refitting the flywheel. good luck, Peter.

Hello Bert, Yes, the easiest thing to do is to retard the ignition. I would also go ahead with the D34 needle too. Good luck, Peter.

Hello Brutus, I am not aware of any heavy flywheel kits for the older motors. You can always retard the ignition for softer low end power (Move the stator plate anti clockwise approx 1mm after marking the original position first). Also, some lads fit extra base gaskets in to soften the compression, you could try fitting an extra 0.5mm thick gasket. Another usefull mod I used to do was to use a D34 needle in the DellOrto carburettor. The standard needle is a D36, the D34 is a little richer at low revs and is my needle of choice for all the bigger Gas Gas motors, 330, 321. It helps with low end control. Bye, Peter B.

Hello there, It is normal for the PRO motors to have a clutch rattle from new, due to the very narrow clutch gears and with them being straight cut. Pulling in the clutch should quieten the noise down, usually completely. If it is a 2002 model, the gearbox is full at 450ml. Always use either a mineral oil, 10 weight or a good ATF rated to Dexron III. Bye, Peter B.

Hello Bigfoot, I've worked on a few PRO motors. If you can get the crank clutch gear off without too much drama (There is a factory puller that grips the gear OD that allows you to extract the gear without any damage) then the only other tool that is needed is the flywheel puller. Most likely problem is the pawl mechanism on the end of the gear shaft, inside the selector drum. This has 2 pawls that engage the drum when the gear shaft is moved. The pawls have tiny hairspring type springs to keep them loaded out. Sometimes these springs can break, pretty unusual though. The engine is straight forward to work on, getting the kickstart spring back into position can be painfull unless you make up a Tee bar tool with an old kickstart boss to allow you to rotate the kickstart shaft and position the spring at the same time. Use stacks of oil on the gears when assembling as they can stick when trying to set up the selector return mechanism. Use a new crankcase gasket and refill with 10 weight mineral or an ATF rated to Dexron III. I don't know what year your PRO is but there are different crankcase gaskets to fit the 2002 models and then all the later ones. Good luck, Peter B.

Hello Bob, I am on my second 300 Gas Gas, fitted with the Hebo 750 gram flywheel weight. It's an 06 Raga 300 which has a far sharper power delivery than my previous 04 model. Both bikes benefit from the extra weight, much more controllable going up rocky rivers and easier to ride in the wet. I haven't tried a 250 PRO or earlier model Gasser with the extra weight and would not have thought this was necessary. I've been riding a long time and like a more controllable power delivery, not something snappy. From the sound of it, you may be best off riding the 250 PRO, the 280 is a bit sharp in power delivery and the 300 just keeps on pulling and can get a rider in trouble. The 250 grips real well and is the easiest bike of the three to ride. Try it standard at first then fit the extra weight if you feel this would help. Make sure you have a 10T gearbox sprocket. Knowing what area you ride in would help. I'm in NZ where the trials are similar to up north in the UK, except much warmer! Lots of rocks, banks, tree roots but no moors. Very slippy in the winter. Bye, Peter.

Hello John, If you are in the Uk then Bill Pye in Great Ayton used to have heaps of spares for Fantics and may be a source of good info. I can't help otherwise but was wondering if you are John Nelson from Guisborough UK? (An old friend). Also, thanks to Slapshot 3 for helping out with posting replies. Bye, Peter B.

Hello Floored, I am on my second 300 Gasser. It's definately a good idea to fit the Hebo 750 gram flywheel weight kit. It would help with getting grip and momentum at low revs. A black tube, slow action throttle would also help. I guess you are in the USA or Canada judging by the English, you can get the kits from one of the GG dealers or ask Rising Sun Imports for more info on the closest help. I don't know what you mean by siping the tyres. Bye, Peter B.