peterb

Hi Weeble, Good that you bought a new cap, as Jon says, it is there for a failsafe mechanism to protect the rest of the selector mechanism. The springs have always been attached to the cap when I have worked on these, try installing with a full 360 degree twist on the spring, mind your fingers. The clutch centre bolt should be reasonably tight, sorry, no torque figures. Before fitting the clutch, check that all of the gears can be selected going up and down the ratios, as this is determined by the spring rest post, which looks like a sleeve with a 4mm Allen screw on top, it is drilled eccentrically to provide a small range of adjustment for the selector central resting position, to adjust, slacken the Allen screw and rotate the sleeve with a 10mm open ended spanner. Bye, PeterB.

Hello Weeble, I agree with Jon and add the following. It's very likely to be the gear change return spring CAP at the end of the gear shaft, clutch side. The cap is pressed together and some of these can rotate out of alignment quite easily when clouting the gear lever on rocks and trees, nothing major if so. To have a look, tip the bike over to the left, remove the clutch cover, leave the coolant circuit intact, mind out not to loose the kickstart shaft washer and tap the clutch centre nut with a drift before undoing with a non-ball ended 4mm allen key. (Don't round off the allen screw). The clutch comes away as one unit if you hold it from the underneath. Beneath the clutch is the end of the gear shaft with the cap and spring. The cap has a centre piece that should be in alignment with the spring tab. If it is out of alignment, remove the cap then you can twist back and then carefully braze the cap parts together if you are stuck for a new part, but best to buy a new cap with spring. Bye, PeterB.

Hi Russell, As Jon says, the bike works well with a 10T. From new, the standard length chain is fine with a 10T for about 20 trials or so then you can either fit the larger snail cams or take out 3 links and fit in a "half" link, which is 2 links long. Bye, PeterB.

Hi there shocksetup, I was having a little problem bleeding the rear brake on a 95 Gasser, it all came good when I unscrewed the reservoir cap, and gently prised out the rubber diaphragm and allowed the unit to vent while I usesd a syringe to force hydraulic oil up through the caliper. Still took a while to bleed and I finished using a screwdriver to operate the master cylinder to achieve a longer stroke. (Rather than relying on the brake pedal actuation) Also, there would be an O ring seal for the oil passageway from one caliper half to the other, this would be worth checking. Years back I did have an awkward bleedin system that I had to rebuild the caliper with oil already in behind the piston, it worked in the end. Persevere. Bye, PeterB.

Hi subanator, You've got it sussed. Inserting extra base gaskets does not increase the primary compression, it does raise the ex. port (shifting power higher up the rev range) and decreases the compression ratio, lowering power slightly. The inlet is controlled by the reed valve opening under vacuum as the piston descends, drawing in a fresh charge of fuel/air. 2 strokes benefit from as high as possible primary compression which is another reason that GG have the oil seals on the inside of the crankcase, more efficiency in the primary compression. Bye, PeterB.

Hi Markkeen, Not such an easy one to diagnose. Your bike is a PRO, as you were riding, it jumped out of gear, locked up and made a grinding noise. Does the motor turn over? - if yes, then does it start up? If not starting then the flywheel key may have sheared. Check with your mates puller. Can you select any gears? If none, or not all of them, you'll need to strip off the clutch cover, leave the water pump hoses on for now. The clutch unit is held in by a central 5mm allen screw, with a vent hole all the way through. Do not use a ball end allen key to undo this. Before undoing, tap with a drift to shock the threads a little then use a flat end allen key. The clutch then pulls off in one unit. Have a look underneath for possible damage, maybe the kickstart quadrant or idler gear. Check the gear lever return spring sited below the clutch - is everything here working properly? If nothing wrong so far, then you'll need to investigate further in the motor, complete stripdown, drain coolant, oil, remove head and barrel as one unit unless you are replacing the head O rings. Motor splits very easily. Good luck, PeterB.

Hi godzilla, You should be able to get these from a bearing supplier. Bottom bearing could be a bit tough to get off, may need a cold chisel to split the inner race. Pack with water proof grease, Mobil HP or similar. Check if there is some sort of water seal on the top bearing, a plastic cup or large O ring. Bye, PeterB.

Hi DrHUD, If it is a PRO and it isn't the crank seal as indicated previously, then it is possible that transmission oil is leaking out from one of the crank case allen bolts. At about the 2pm position behind the stator, this case bolt has a copper washer to seal off a drilled oil way passage, worth a look. Bye, PeterB.

Hi Finn, I haven't worked on the GG 80's, I think the engine is either Minarelli or Moto Morini, not sure what type of ignition system is fitted. A friends GG 80 bike had ignition problems that were traced to a screw coming undone in the stator area that caused a bit of damage, worth a look. There is usually no electronic eye for ign pick up, just a small coil that provides a regulated burst of current at the right time (when a passing magnet embedded in the flywheel rotates across the coil). From my understanding of the ign system, this coil provides the representation for the motor rpm so an algorithm for the ignition firing versus rpm can be tracked. Alternatively, it could be the trigger coil signalling when the ignition should fire and there would be another system to determine the motor rpm to enable the mapping to operate. Could be wrong too! Bye, PeterB.

Hi Mataos, I have info on the 305, similar motor save for the water cooling - just looking at it. Recommended oil is as you state, 500ml 80 weight. Bye, PeterB.

The TRW company manufactures major components for the world wide automotive industry, I don't know if they are working in the aerospace sector. The team is based in Milan, run by Quirino Tironi, a bit of an engineering type. They also have Kiwi Jake Whitaker on board, not long turned 16 year old who is riding the 125 Honda based 4RT developed by TRW. Bye, PeterB.

Hi EDGAS, When you look into the end of the silencer, where it fits onto the centre box, there should be an aluminium sleeve/tube with one or two grooves machined for fitting the O rings. If your bike has this piece loose, it needs welding back into place. This aluminium piece which holds the O rings, fits over the spigot on the centre box. Inside the silencer, there is a steel perforated tube that Jon explained about, this is removeable and has fibre packing wrapped around it. This perforated tube pushes into the aluminium sleeve/tube at the entry point of the silencer. Bye, PeterB.

Hello Mark, I'd agree with Jon. Do you say it is the 280 prior to the PRO? If so, these motors are pretty reliable and not prone to any selector fork problems. Have a look under the clutch cover, it could be that someone had recently worked on the clutch and forgot to install/look out for the push rod ball bearing. I know of two cases in this neck of the woods where owners have forgotten about this bearing and dramatically found it smashing chunks out of their clutch gears, really! Not much else to wrong with these motors. Good luck. PeterB.

If you mean the PRO range, then it was 2002 when they were released. Bye, PeterB.

Hi Jenkinsm, Had a similar problem with a friends bike, it was the clutch hose that was trapped under the headstock area behind one of the electronics boxes, the hose was squashed and created a constriction for the hydraulic fluid. A new hose solved this problem. Bye, PeterB.

Hello Jaan, I have successfully used a standard DellOrto PHBL 26 carb, jetted for a Gas Gas PRO 250/280/300 but fitted a 95 main jet for many older bikes. Bultaco 325, 250's and an Ossa MAR. They are easy to work on and easy to get a hold of jets, also not too dear. Performance is good. Bye, PeterB.

Hi Anton, I also have a 1989 250 GG aire in my collection, not a bad bike for the year. Forks are Marzocchi, seals are 35x47x7, same as a 70's Bultaco Sherpa. You should be able to free up the front caliper using the brake lever, squeezing out the pistons. I have a Brembo seal kit here but probably would like to keep a hold of it. There is no service manual for this bike, feel free to use the forum for any particular questions, or you can always PM me (personal message) and use my email address for help. Brake pads are the same as used on the 95 330's, should be easy to get hold of. Linkage bearings similar to later mid 90's bikes. Clutch plates differ slightly to the 330's, but you can easily fit these with a little filing of the tangs. The 89 internals are well made, quite sturdy, massive kickstart gears. I replaced my cylinder thinking the nickasil had gone porous (looked like surface pin holes all over) but the new one was identical! Pistons are still available but take an age to deliver, you can use piston rings from an earlier 250 Sherpa - can't remember now if one was a dykes and one plain, best to check first. Crank seals are same as 330, readily available hi temp viton. If you are really stuck, I have a new air filter here and maybe a transport method to the UK - one of our riders is off to the SSDT in 3 weeks. Footrests are terrible, best to weld on a set of Hebo pegs but mount these as low as possible and as far back as possible. Bye, PeterB.

Hi sheffieldtrials, The 93 330 has barrel induction and hydraulic clutch slave. The 91 250 (Delta) has the same RHS case as the 93 330, the LHS is the same except for not having the hydraulic clutch slave. I would say that the 93 330 cases would be interchangeable if you include for a clutch hydraulic slave. Bye, PeterB.

Hi OTH, I had one of those Benley's about 40 years ago (I were just a lad). I thought the tank was a superb shape, yours is a good example. I seized the big ends, not cleaned out enough during a strip down (well, I was pretty young then), put in another motor then swapped it for a YS 1 I think (Yamaha 100 twin) plus cash - seized that too! Bye, PeterB.

Hi Steve, The fan motor on the PRO models do seem to be on for longer periods than other makes and they seem to cut in quite early, it's all very normal though. Try not to aim a water jet at the fan motor Bye, PeterB.

Hi Neo, Yes, it is the same thing. The physical stops preventing the petals from opening any further out, measured from the tip of the stop to the reed casing at a perpendicular. Have a look through the USA GG site, there is very likely to be something there covering this. Sorry I can't help more, not had to look at one of these ever. Bye, PeterB.

I've ridden Gas Gas since 1992, in the expert grade down here and not quite as tall as Douggie (nor as skillful) but have always preferred the grunty power of a 330/300 motor over the smaller engines. I currently ride a 300 Raga, my second 300 and will be getting onto an 08 Raga 300 when available. I like the low end pull of the 300's, and with a flywheel weight fitted and 10T spkt, find the bike is perfect for me in all conditions. It has very controllable "rolly" power at low revs which is great up the creeks (becks) and has instant oomph for lofting the wheel up bigger rocks. I'd say a 250 is about the easiest bike to ride but qualify that with a mention that the motor is very lively and probably not a easy as my 300 when riding up slippy creeks. Like someone else mentioned earlier, when new, the 300 Raga has enormous power and a very quick response to throttle input - this does wear off a little with use though - it's perfect with a weight. Best thing really is to try them all, the 08 280 I rode in Sept felt very similar to the 300 but was new and not run in, previous 280's I've tried were quite sharp in power delivery and more suited to splatting onto big dry rocks. Bye, PeterB.

Hi Neo, Was wondering if you get responses like "My name is Morpheous" and other such stuff! Anyway, I don't have the specs on the 70 motor but you should be safe with 3.5mm at a start I tried wider settings on 250/270/280 GG motors without good results, just out of interest. Have you taken the poll under the general info? Bye, PeterB.

Hi Tom, I can't remember if your bike was Raga or std 300. If a Raga 300, then the factory settings are too lean with a Keihin carb, go with a 126 main jet and a GJH needle, bottom notch, also a smaller pilot jet, try a 40 as they were set up too rich on the low end. If a std bike with DellOrto, then, I don't know what jets are supplied for 2008 so can't really help. Usually the DellOrto carbs were always sent out a little on the rich side with a 118 main like Jon mentioned. Have a look at the needle clip position which should be at the second to bottom position. Also, it is likely (if it is a DellOrto) that the float height is not quite correct, take off the float bowl, tip up the carb and check to see if the brass float arms are parallel to the bowl mating face on the body - I think the measurement is 18.5mm but a visual will suffice. Bye, PeterB.

Hi Clive, I don't have a Beta but thought you maybe should try this posting in the Beta section to get a few responses. I have used ATF in all of my Gas Gas bikes for over 15 years, it works well and helps reduce drag. I'd stick with ATF. Bye, PeterB.