peterb

Hi Dan, what year is the bike and roughly how many hours has the motor done? Vertigos are not unduly noisey from the clutch area, like say on a GG clutch, if the noise has become worse over time then either something has worn or come loose. Two areas to look at, the clutch centre bolt is an M5 like the GG, check this has not come loose. Behind the bolt is a machined washer, check the washer has not fractured from overtightening and "let go" The other possibility is the kickstart idle gear, this has a stub shaft that runs in a narrow needle roller, check this for play. Bye, Peter B.

Or 2 stroke?

There were many problems with the Ducati systems on the GG trials bikes, and like petert above, we replaced quite a number with Kokusan and never looked back. Most of the problems I have seen were with the regulator, the aluminium cased unit, which if you look at the green potting underneath, you may find a brown discoloured over heated area which invariably is a sign of a component that has cooked. The regulator would need replacing. There were two types, identifiable by having a black or a blue connector. I think one was for the 300, I don't know which colour though. Are you able to borrow another regulator to try out? If you are in the UK, then GG UK should be able to help with this part. Good luck. Bye, Peter B.

Buongiorno Guido, most, if not all of the current 2T trial motors use this type of fixing screw to hold a plastic plug in place, to the inner side of each crankshaft flywheel. The flywheels are machined opposite the crank pin to reduce weight there, in order to provide a balancing effect. As the steel is machined away, the volume removed is replaced with the lighter weight plastic so as to maintain maximum primary compression. Bye, Peter B.

Hi Dan, the bike must be a 2016 model, later bikes have the steel sleeve drilled and pinned with a 3mm roll pin. With the rear wheel out, you should be able to gain access to the crankcase housing part, where the sleeve resides, to carefully drill into the aluminium and stop drilling when you reach the steel sleeve, mark the depth with tape on the drill bit. We have used an M5 grub screw to lock in the sleeve for a similar job, use a 4.2 diameter drill bit for this, then tap the hole to M5, again, mark the depth on the final plug tap. You need to bear in maind that you need space to turn the tap wrench, a Tee wrench works well here. You may be able to get a pair of pliers on the sleeve end, which is worth a try first though there is little there to get a hold of. The red anodised sleeve under the swinging arm bolt is a close fit into the frame, they need to be removed if you want to take the motor out, they have a large internal thread to help removal, think it is M20 x 2 but would need to confirm. Bye, Peter B.

Hi ric, you can drill a 4mm diameter hole in the "gearbox plate" the aluminium RHS plate, at the lowest point on the bottom right corner, without this hole, the oil tends to mostly stay in the right side of the gearbox. The factory adopted this mod on either the 2014 or the 2015 bikes. Bye, Peter B.

Using Loctite works well. I don't think the 2011 and 2012 models were machined deeper behind the bearing to accept the through bolt. Have a look at your crankcase when you do the loctite mod to see if there is sufficient room, the through bolt has a wide flat head approx 4mm thick. Use a de-greaser before loctiting. Bye, Peter B.

The problem is likely to be the primary gear shaft moving out from it's LHS ball race. I am not sure if the 2012 bike has a bolt with left hand thread to keep the shaft in it's correct place in the bearing, think this was introduced for 2013. You would know if your motor has this bolt, it exits through the clutch centre hub. If there was no bolt, then the clicking problem is caused by the shaft moving away from the LHS bearing. The problem would show up some time after the gearbox was working perfectly well and then get worse. Previous to the through bolt, there is nothing to prevent the shaft from moving out of it's LHS bearing, which can cause random gears to mesh with dire consequences. To fix this problem, strip out the gear cluster leaving it in gear to do so, not neutral. Clean the oil away from the primary shaft crankcase side bearing, on the primary shaft end, use a small die grinder to grind in about 6 dimples into the radial surface of the shaft where it fits into the bearing. This is to provide a "key" to allow loctite to bond to. Use a blue loctite 243 on this surface (after de-greasing first) when re-assembling the gear cluster. Alternatively, if your motor has a through bolt, then the problem may simply be the adjustment for the gear selector, which requires the cluster to be removed to get at. Where the selector drum sits on the gearbox plate, the RHS, there is an eccentric pin on a 10mm hex with a lock nut behind. Moving this adjusts the throw of the gear selector one way to another to obtain sufficient rotation of the drum to select gears going up and down the ratios. Hope this helps, bye, Peter B.

Hi jsp, I have not needed to remove the Vertigo's wheel bearings yet, we always re-pack the wheel bearings from new with waterproof grease but on other bikes like GG, Ossa and JGAS I turn up a drift to a slide fit inside the bearing ID which fits up against the stepped inner sleeve. After heating the bearing housing with boiling water, tap the drift which then knocks out the bearing, use boiling water on the housing to re-fit a new re-packed bearing. Some hubs have a loose sleeve which is not spigoted into the bearings, these can be a bit more problematic, especially if there is no available movement. Bye, Peter B.

If you can't lever the spacer off with two screwdrivers, opposite each other, then try a bearing separator, gripping the outer back edge and use this to tap out. We always assemble ours with grease. Bye, Peter B.

I'm not sure but they may be Alpina yokes. I fitted a pair to my 325 to move the bar position foreward, also tucked the fork angle in a little. Bye, Peter B.

When the oil seal was replaced, was the sleeve removed and a new O ring fitted behind there? After working many years on GG and Ossa bikes with the same sealing arrangement, the oil seal was never a leak path problem, always the O ring/s behind the sleeve. There is another possible leak area if oil is not passing from this area, have you checked the gear position sensor housing and the primary shaft cover, just above. Bye, Peter B.

It is difficult to diagnose when the motor is not running. If the clicking noise is there in any gear, or even in neutral with the motor running then it is very likely that the kickstart idler gear has a chipped/damaged tooth or teeth, which would be reasonably common on an older GG Pro motor. Other problems in this area are likely to be the kickstart quadrant, the 5 tooth gear that engages with the idler to turn the clutch gear when kicking over. Have a look on the clutch gear, the basket we call it, to see if any of the teeth are damaged too. Bye, Peter B.

I don't know what the actual compression ratio is on the 300, but imagine it would be around 9:1. Therefore if you used a compression tester screwed into the spark plug hole and kicked the motor over, you would expect to read 14.7 x 9 psi, or approx 130 psi from a healthy top end. Bye, Peter B.

There's nowt wrong with ATF, also used this for well over 20 years on lots of bikes. The probable reason why the fibres came away would be due to the glue used at the time was a water soluble glue for environmental reasons (I think the manufacturer at that time was Hoerbigger in Germany). When the water pump seal gives way and lets water in to the gearbox, the oil turns milky and if not changed soon enough, the fibre plates start to come apart. Sureflex can supply plates for these older bikes. Bye, Peter B.

Yes, the spacer/sleeve is a slide fit on the output shaft and will only be tight against the seal. The O ring is behind there. The sleeve should be able to be pulled off with pliers. It is P/N V-0309, output shaft sleeve. Sorry, I can't load the drawing, it's a PDF file. Bye, Peter B.

Behind the sprocket is a sleeve that rides in the oil seal. At the inner end of the sleevel is a 25 x 1.5 O ring. Similar arrangement to Ossa and GG. It may be that the O ring has been damaged during assembly, it is quite easy to do and also very easy to get at as the sleeve pulls out after the sprocket has been removed. Worth a look. Bye, Peter B.

Later selector shafts were designed/built stronger, same for the selector drum which had more material around the indexing area. It would be unusual for the clutch outer drive ring to wear, do you mean the idler gear behind the clutch basket? This is the gear that is engaged by the kickstart pawl, the 5 tooth gear or quadrant. The idler does wear. There were 2 gearbox suppliers, best one was from Italy the other from Spain. The Spanish gears were machined on the OD plus a few more problem areas that were introduced. To determine which gear set that you have, measure the OD of the idler gear, if 50.80mm or less, it is Spanish, if 51.30mm then Italian. Lewisport would know of this. When you do re-assemble into the crankcase, seeing that you do not have the clutch through bolt system, the LHS of the primary shaft needs to be loctited in position inside the LHS bearing. Prepare the end of the primary shaft by grinding dimples around the outer shaft surface, to provide a keying surface for the loctite. If not loctited in position, there is a chance the shaft will move outwards, with resulting gear damage likely. Bye, Peter B.

Agree that it looks like a 1999 model. Although a heavy bike compared to the later 2002 onwards PRO Gas Gas models, the motor is well built with few problems. The water pump shaft/seal will wear allowing coolant to enter the gearbox. If this is the case, you would see the gearbox oil through the sight glass on the RHS looking a little milky white in colour as the mix emulsifies. If that has happened, it is very possible that the clutch fibre plates would swell creating a heavy action clutch which also drags. But, not a real problem, both the water pump shaft/seal kits and Sureflex clutch packs should be readily available from GG in the UK. Linkage bearings wear quickly and are easily available as a replacement kit set. The rest of the bike is fine wear wise. Bye, Peter B.

Just a bit more to add to the above. The Torx cut/pressed/stamped into the end of the clutch securing bolt was never very well performed and you may find that a T10 or T15 Torx key is needed to hold the bolt. The LH threaded nut needs a 12mm socket to undo. It was never intended to be very tightly nipped up as the bolt is hollow and easily sheared off. Use a dab of blue loctite on this thread when re-fitting. Don't over tighten. If it's stuck in first gear, the selector shaft is likely to be broken at the "pawl" end, bit weak there in the early bikes. And/or, at the worst case - the selector drum has been cracked, maybe not so easy to find a new one. Have a good look, it can be just a hairline crack. When re-assembling the gearbox, it must be in a gear, not neutral as it won't go back in the case. The cluster usually fits back no problem, needing a few light taps on the clutch to ensure it is home. Clean the oil off the 5 shouldered 3mm hex allen bolts, only use a dab of blue loctite on the ends of the thread. Best allen key I found was made by Beta Tools, Italy, no relation to the bikes, these are what the factory used to use. Get the all steel Tee handled 3mm wrench. Look out for the 2 x 25 OD O rings fitted to the outfut shaft sleeve, if only one fitted, there is a good chance of leakage from here. Bye, Peter B.

Message for bashplate in Christchurch, HPC coatings in Auckland have been working with engine parts coatings for many years, I know they have coated piston crowns but have not heard of coating the piston skirt, perhaps they do this also. Here is their site www.hpcoatings.co.nz/ Bye, Peter B

1) What has been reworked on the clutch? Dragging can be from a number of areas, leaking slave seals, passing master cylinder seal (most likely, even from new), oil too viscous or warped clutch plates. I'd first check the oil, which should be fine coming from the factory, then try a new kit in the master cylinder. 2) Can you better explain "flighty" Are they a bit sharp in pick up, are they a bit lean in the mixture? Some years back GG sent out bikes with a homologated set of jets in the carb, then supplied a "race" set for proper trials use, pilot and main jet from memory. If a DellOrto carb, should be around 33 pilot and 115 main. 3) Hard starting may be the carb float arms are not parallel with the main body, they could be allowing the floats to close the fuel valve too soon if set wrongly. There is a height measurement too, approx 18.5mm from the body when upside down, more or less. Just look for being parallel. Bye, Peter B.

The bearings have O ring seals fitted as standard, we add an extra O ring onto each of the 6 bushes that ride in the bearings to provide more sealing which has worked well. No need to remove the swinging arm to get to these. Bye, Peter B.

Lotus54, you are correct, the cap squeezes over an O ring on the injector, which you can hold together in your hand. I have done this before as a functional check to see if the injector was delivering fuel. You can see the fuel spray exiting the injector. Bye, Peter B.

Nothing on the Combat or Ice models.