peterb

Pretty sure they were 12v, Have a look at the headlamp bulb for the voltage info. bye Peter B.

I always found my Ossa's to be very fuel efficient when properly set up, far better than any of my GG's. Perhaps your bike is running rich. If someone has adjusted the TPS, even if just loosening the clamping screw and re-tightening again, this disturbs the programmed relationship between the fuel/air ratio and the throttle butterfly position. Have a look at the spark plug colour, with normal trials riding and a few hill climbs, there should be a chocolate brown colour on the plug electrodes, if black and sooty then the set up is too rich. Best plug for everyday use is an Iridium electrode heat range 4. Bye, Peter B.

The Honda P/Ns are different for the two manifolds: TLM220 = 16210 KR8 020, the TLM240 = 16210 F8F 000. Here is a link for the TLM240 parts list: https://www.cmsnl.com/honda-tlm240r-1987-hrc_model35474/partslist/#.XAyGiHozbaZ Bye, Peter B.

Looking at your photo, the first gear on the left is 1st gear. On the early bikes, this can cause a problem as there was insufficient oil feed to the bearing surface that only became a problem when belting along in 6th gear. The 1st gear is being rotated on the shaft when 6th is engaged, or driving, so you can understand that it is rotating pretty fast when you are in 6th and getting a move on. Due to a lack of oil, heat would build up and ultimately the 1st gear could seize. While there is a small oil hole on the shaft bearing surface, there is only the clearance between the gear and shaft to allow oil to access this area. We modified this by machining a spiral type groove across the shaft bearing surface to allow for an oil feed path, which worked. Later models, had a spiral machined into the first gear which did the trick, and had a larger oil hole in the shaft. Bye, Peter B.

You need to remove number 2 by sliding it along a bit at a time (poco a poco) which allows the secondary shaft to wriggle out as you fiddle with the primary shaft, moving the primary shaft gears to allow the secondary shaft to be removed. With the secondary shaft removed, you then have access to the kickstart idler gear stub shaft, held in by a circlip and a shim behind that. With careful manipulation of the primary shaft (you don't need to remove it to get the stub shaft off) you can gain enough clearance to remove the stub shaft. Even when new, the primary shaft clutch basket was pretty sloppy. Bye, Peter B.

You probably removed the plug on the lower right side of the motor. This should have a copper washer fitted. The plug houses the gear selector index plunger: a spring and 12mm diameter ball bearing that pushes up against the shift cam plate. You may have lost the spring while undoing the plug. The old P/N is 8403155, not sure what the latest number would be. I can't remember if the bearing is captive or not, it not then you may have lost this also. Bye, Peter B.

The JT35 was only made as a 1995 year model. The blue model in 1996 was called a JT370. Bye, Peter B.

Hi Matt, When the idler gear stub shaft bush wears considerably, this creates a whining noise, most noticeable when in 2nd gear. The neutral notch indent shape was changed on later drums to provide a more positive location. The wear on your shift drum is not bad, it's hard to escape the wear as the spring tension on the cam follower wheel is really strong and the wheel width is quite narrow. I would not machine the neutral position on the drum, the wall thickness there is really thin and you would machine through the hard surfacing, I can't remember if these were ENC plated or plain hard anodised. The wear shown on the drum would be insufficient to allow the gearbox to drop into gear. It is likely that either the cam follower return spring has weakened or the selector shaft position spring has failed or is not in the correct position. The selector shaft position spring is set up using an eccentric adjuster to allow the shift rotation to move the selector forks the correct distance in both directions, up and down the gears. It's not easy to set up either. In essence, there should be a lot of tension on both the cam follower spring and the selector spring. Yes, drill a 4.5mm oil hole in the gearbox plate, at it's lowest point, you can see it, right in the corner. When the gearbox is in place, there is radial play on both shafts, more so on the primary (clutch) shaft, excessive play on the secondary shaft is due to the idler gear stub shaft bush wearing, these can be replaced. We modified the gearbox plate idler gear bearing housing, drilling a 2.5 diameter hole through the top of the housing, counterbored half way down with a 4mm diameter drill to provide an oil well and feed system for the bush, also ground grooves into the shaft bearing areas to allow oil to enter and leave the bearing areas, probably a few more things to make the gearbox last that I would have to think about. With the gearbox out of the case, the shafts flop around like you would think they were never going to work. Have a look at the end of the primary shaft, the left side where it fits into the bearing, the shaft was modded by machining about 6 little dimples to provide an irregular surface for keying in the loctite. If there are non there now, they are easy to grind in with a small die grinder or Dremmel type tool You are not able to install the later model clutch fixing bolt, there is insufficient metal behind the LHS bearing to do this. From 2012 onwards, the crank case was changed in this area to provide clearance for the bolt. Bye, Peter B.

As canada280i said, it is very likely that the primary shaft has been loctited in place, to prevent the shaft from working out of it's LHS bearing. They do come out ok even with loctite, you should be able to tap the cluster out by tapping on the output shaft and the gear selector shaft, lightly with a hard rubber mallet. With it dropping into gear, it's possible that the selector shaft spring has failed, or one of the end arms of the selector shaft has broken. If light tapping doesn't work, you will need to make a plate that is drilled to the BCD (Bolt circle diameter) of the clutch centre bolts, use the 18 bolts to fix this to the clutch centre, and use your favourite slide hammer to extract the primary shaft as you tap the output shaft (not at the same time though!) Bye, Peter B.

The usual reason for the rectifier getting fried is either the voltage regulator has failed (the box under the headstock) or the voltage regulator has a bad ground connection. I'm not 100% sure about the wiring. Check the voltage reg for having a good ground before hooking up and starting the bike, or install a new voltage regulator.. Bye, Peter B.

Been a long time now, but I think there is a press fit annular strip of sheet steel that covers the spoke ends, it should just prise off, have a close look in the hub, the rear sprocket is likely holding it in place. Bye, Peter B.

From your description it seems that you stalled the motor before the piston nipped up, so likely then that there is no piston/bore damage that usually happens when the bikes land upside down and the throttle sticks wide open till engine seizure. Have a look at the throttle needle clip, and see if there is a plate on top of the needle that holds it in place, it's possible that the needle is allowed to float without any top plate, or is perhaps installed incorrectly. I have had a throttle slide with a nick on the slide surface caused by something getting through the air filter in the past, that would occasionally stick open. Bye, Peter B.

I wouldn't drill out the back of the piston as that would weaken it. I have a new slave kit that I would need to locate first, that I could take a photo of the bearing height, measure it and let you know. I tried running 4 clutch springs on a 330 GG years back, was much easier on your finger, but would slip with a handful of revs in 4th, probably fine on a 160. Bye, Peter B.

A good friend of mine, who rides trials regularly all through the year, went 10 years on a GG 330 without taking the head and cylinder off, and it still did not rattle and still performed as good as the day he bought it. There would have been many more hours than 400 on that bike. If you haven't drowned your bike in water and the motor doesn't have a piston rattle and it is still going well, then I'd be inclined to leave it alone, the top end is rather hard wearing with a nikasil bore, as mentioned earlier and rings which I am pretty sure are nitrided. Bye, Peter B.

Looking at the photo of the slave cylinder, there is a 5 or 6mm diameter ball bearing that, from memory, sits flush with the top surface of the hole in the slave piston. These ball bearings have been known to become pushed further in over the course of time, eventually going in so far as to give the symptoms of what you are experiencing. The slave piston, when actuated would come to a mechanical stop on the crank case before the clutch was fully disengaged and the clutch lever would feel as though it has reached it's actuating limits. A replacement slave cylinder kit is needed, if this is the case. You may be able to try inserting an extra ball bearing, that can be removed, just to try this out to make sure that this is the problem. With regards to the gearbox oil, for over 25 years we have run ATF rated to Dexron III in all models of Gas Gas trials bikes without problems. For your model, the gearbox is stated taking 700ml, you are absolutely fine to run with 600ml, from the factory. Bye, Peter B.

I agree with ric h, that it could be the crank bearings. The left side has a caged needle roller bearing, the axial control of the crankshaft is only down to the right side ball race, a similar bearing to the ones used by GG. If this has worn, then you would tend to feel vibrations through the footrests, getting worse as the revs rise, you would be able to hear it too as a rumbling noise. The TPS would not cause this vibration. There is no other way to check that this right side bearing has failed, only from the motor vibration and the sound. It is not an easy bearing to replace, you would need an Ossa crank bearing, while it is the same type as a GG and JGAS, the Ossa bearing has a short slot machined in the outer casing to locate a 3mm allen screw. Ask for help locally to determine what the vibration is, if it is not that bad, it could be that something has come loose in the fuel tank, pump or filter. Bye, Peter B.

Ciao Gobig, I had the same problem with the front wheel spindle, the aluminium spindle had locked onto the bare steel spacer in between the wheel bearings. Make sure the fork slider lock bolts are loose, support the fork slider where the spindle would be removed from with a heavy piece of wood, then try tapping out the spindle with a hammer and brass or aluminium drift. Hopefully this will work. Ciao, Peter B.

Dobroe utro venickey, I have front wheel spokes for a 94 model, there are 2 lengths, 236mm and 238mm, 1 for each side of the hub. Part number R130000 and R140000. I think I can post you these for not much money, it is ok, when I am in Russia then you can buy me a beer! Can you use the "Messages" part of the forum to send me details of your address? I teach engineering in a high school, we have students from all around the world, one is called Iaroslav, he is from Russia and speaks good English, always good to learn a few words. Bye, Peter B.

Dobroe utro venickey, kak vwy? You must be close to Dzhaore, maybe there is a cycle or motorcycle repair shop there who could make a new spoke for you. The problem with your bike is that it is 24 years old and the spokes on these older bikes do tend to seize up in the nipples, best to leave the other spokes alone for the time being. You can remove the spoke and continue riding no problem. If you cannot find a new spoke/nipple, I probably have one at home you can have, but then there could be a post/delivery problem to where you are, I will check it out. Bye, Peter B.

Dobroe utro venickey, the bike is reasonably reliable. There is no manual for this. Although the recommended gearbox oil is 700ml, it is ok to use 600ml of ATF rated to Dexron III. The water pump seal and shaft wear, which allows coolant to enter the gearbox and mix with the oil. The water/coolant can create a problem with the glue used on the clutch fibres, allowing them to lift away from the steel. This makes the clutch action drag when pulled in. On your carburettor, the pilot adjusting screw should be set to around 3.5 turns out, from fully in as a starting point. The throttle needle in the second notch from the bottom. The suspension linkage, as most trials bikes, requires stripping, cleaning and greasing with a waterproof grease. Hope this helps. Bye, Peter B.

I agree with heffergm that Grattarola is not to blame. It is wrong for the observer to change his observed score due to outside interference, I hope that the FIM listen to reason and revert the score back to what was initially given, that would be the correct and just act to do. Bye, Peter B.

I don't think the heat is going to damage anything there, I am not sure if the bushes are steel or bronze, either way a bit of heat shouldn't hurt. Heat and a big hammer should get the spindle to move. There would likely be a seal there either side, best to remove these before heating, unless you already have. Good luck, Peter B.

If it were just a soft fall then it is possible that the shift fork has not bent. What can happen is that the cupped sleeve that the shift return spring sits on may have been damaged. This is usually referred to as the top hat, as it looks like a top hat. This is made in two parts, an inner piece that is pressed into a tube in a specific location relative to the spring tang, when the bike is dropped on the gear lever side, the force of the gear lever smacking the ground can rotate the inner piece inside the top hat. Visually it would look ok, only the inner is now out of alignment which does not allow the gears to be selected correctly. This could be what your problem is. The top hat used to be supplied with the return spring attached so it is easy to replace. Try this first before tearing the motor down. It is located behind the clutch basket. Bye, Peter B.

The corks are supposed to be there to fill in the machined holes in the flywheels. The early 270 GG had a 3 ring piston, later ones were supplied with a piston with 2 rings. Bye, Peter B.

Hi Ric, we machined out the hubs to fit ball races, 60042RS from memory, and made up a wheel spacer to suit, with the tyre off, the wheel can sit flat on a large milling machine table. Pretty sure the kit was just a sleeve and a smaller than 6004 ball race. Bye, Peter B.