neonsurge

We'd been riding for a good couple of hours when events started to take what would eventually turn out to be a worrying and dangerous turn: Steve: "Ian, your bike sounds funny mate." Ian: "Funny? In what way?" Steve: "Like it's overheating or summat." Terry: "It's not squirting steam or anything but summat's definitely up. Better head back to the van and take a look." 10 minutes later: Steve: "Ian, there's no bloody coolant in here! When did you last check it?" Ian: "Errrmmm..." Mocking and hilarity ensues (approx. 5 minutes). Steve: "So, anyone got any water?" Terry: "I've got some in the truck. Here we go, let's fill 'er up." One litre of fluid is now dumped into the ailing GasGas. Terry: "Hang on a sec. Does this water smell funny to you?" Ian: "Errmmmm..." Steve: "That's not water, it's bloody petrol you pillock!" More mocking and hilarity ensues. Eventually all of the petrol is drained out of the bike by simply removing the water pump cover (don't ask) and after briefly debating the cooling properties of warm urine, some water is eventually located in Terry's truck. He'd been carrying around 2 liters of petrol and 2 litres of water in identical containers. Since the petrol container wasn't full when originally located, we wondered what Terry had been drinking all afternoon Anyway, several flushes later, the GasGas is once again operational and despite it's less-than-recommended cooling (hey, anything's better than nothing, right?) unsurprisingly sounds happier than it has done for weeks! Maybe you had to be there, but I've since wondered what the consequences of petrol in the cooling system would be if we hadn't noticed. Thoughts?

Perhaps you should ask Adam Raga. He must have some truly awesome excuses because he always seems to be able argue his score down at the end of WTC events

Got the new issue of TBM this morning, complete with "YOU HAVE USED WORDS OR A PHRASE WHICH ARE NOT PERMITTED ON THIS WEBSITE. PLEASE DELETE YOUR POST/TOPIC. DO NOT TRY TO CIRCUMVENT THE FILTERS IN PLACE ON THIS WEBSITE" supplement (this is the stuff that they were planning to produce as a seperate mag before TMX suddenly jumped into the market - in fact, editor Si Melber has a dig at TMX in his editorial column.) Anyway, I haven't read all the way through yet but it certainly seems to be true to the TBM ethos, as promised: "Say what you think and bugger the consequences." Considering the main feature is a 5-bike head to head test using Melber, Mike Rapley and John Sunter as test riders, there's no doubt that at least one of the trials importers isn't going to be happy but in many ways I think that's the right approach. If a magazine has the respect of the public, it doesn't matter what the importers think because they need the magazines more than the magazines need them. And the TBM boys have nothing to lose at this point... Looking good so far - check it out, but be warned that the mag is 80% trail and enduro so

It's a little piece of metal that sits in a slot in the shaft that the flywheel is on and locates into a corresponding slot on the flywheel to prevent it from rotating on the shaft.

I mentioned this in another recent thread regarding carb problems, but I've always found the nice people at Allen's Performance to be exceptionally helpful whenever I've phoned with daft questions about the VM26. Next day delivery on parts as well! Nope, I don't work for and am not related to anyone at Allen's!

If you do a search on this forum, you'll find that engine knocking both during hard acceleration and when rolling off from full throttle is a fairly common problem on '02 and '03 Rev-3s (it doesn't seem to affect earlier or later bikes as much...no idea why.) Try a higher octane fuel - Shell Optimax or other super unleaded if you can get it. That usually improves things but in some cases (like mine!), doesn't cure it completely. What finally sorted it for me was going up a size on the pilot jet from 30 to 32.5 and setting the carb up properly according to the procedure outlined in the Mikuni VM-series tuning manual (which can be downloaded from Mikuni's web site or drop me a PM and I'll email you a copy). If you need to buy jets, I recommend Mikuni/Keihin specialists Allen's Performance. If you're still having problems after that and you're unsure of the history of the bike, take a look at the timing. Remove the flywheel (good opportunity to check the woodruff key at the same time) and look at the stator plate. If the adjuster screws are right in the middle of their slots, the timing's pretty much where it should be and probably doesn't need adjusting. If the timing's obviously advanced or retarded, it's probably worth getting it set properly using a guage or strobe. Good luck!

I believe the rule book doesn't say that you MUST have covered arms, it says "strongly recommended" (or something like that).

definitely agree with JTT, mixture screw should always be the first thing to check. The mixture screw and pilot jet are not the same thing

Gotta disagree with you on that one. OK, it's not a Gasser but I had a very bad knock on my Rev-3. Setting up the carb according to Mikuni's own tuning manual made absolutely no difference. Switching to super unleaded improved things a little bit but didn't cure it completely. What finally sorted it was going up one size on the pilot jet. Simple as that. Factory carb setup will only ever be a compromise. To say that the factory settings should work for everyone, anywhere, regardless of altitude and pervasive relative humidity etc. is simply wrong. It's exactly the same with the suspension settings: What works for a skinny 10 stone rock-hopping Spanish test rider is unlikely to work for a 17 stone mudplugging Yorkshireman!

Some very useful information in this thread - definitely to be filed away under "for future reference"! After cleaning and stripping the bike yesterday, I think that it's very unlikely that an effective weld would be possible; the part that's broken off is very small and it looks like there are a couple of small fragments missing. A new part has been ordered. Thanks for everyone's advice (and sympathy!)

I spoke to Lampkins' yesterday and a Synt yoke definitely WON'T fit a Rev-3. And after disassembling the front end of the bike it looks like the broken piece is too small to be welded New part ordered.

Yeah, seen that Stu but unless I can get it for next to nothing, I can't really afford to take a flyer on it at the moment. I guess I could email some measurements to the seller, but it looks like there are a couple of people chasing it at the moment. Thanks for the heads-up though!

Thanks for everyone's advice. I'll drop into my local dealer at lunchtime to see if he's got a yoke from a scrapper and failing that, get a price on a replacement. If my credit card starts to melt, I'll ask around to see if anyone knows a good welder locally.

Due to incompetent spannering, I've broken the upper yoke on my Rev-3 (right down the middle of the pinch bolt hole). Is this repairable? Could it be welded and the hole retapped or am I looking at a forking over a huge pile of melvins for a replacement casting? My bike maintenance fund is somewhat depleted of late so I'm pursuing every alternative before making a call to John Lampkins... all advice appreciated!

I'll second the BVM recommendation. Extremely helpful and very quick (next day) delivery. You might also try LeisureTrail. I bought loads off stuff from them during my trailriding days and although I haven't used them for a while I understand that they're now a Beta trials dealer and their service was always very good.

Well, after joining and venting the air lines are described in the thread I linked to and setting the float height according to BillyT's specification (do a search for "float height"), I've never had a problem with fuel leaking from the carb. AFAIK all the factory modification does is increase the capacity of the float bowl to ensure a consistent supply of fuel when the bike's at extreme angles (when doing really big splats for example). Alternatively you could sell the Beta and buy a Sherco because they have absolutely no issues at all and never, ever go wrong

The leaky carb problem is easy to fix. See here.

I've just noticed a big crack in the upper yolk on my '02 Rev3 near the pinch bolt. Guess I overtightened it and hit something hard at an angle during the trial earlier this week. Anyway, having just spent quite a bit of wedge replacing seals, bearings, C&S etc., the bike maintenance fund is somewhat depleted so I'm trawling around looking for a cheap replacement. Are the yolks on all Rev3s the same? What about earlier models, would a part from one of those fit? There are a couple of complete assemblies on eBay, but the description says "from a Beta trials bike approx. '96/'97 - no further model information". Failing that, anyone got an upper yolk they'd like to sell me?

I used to know a bloke with an XR650R that he called "the big red pig" (BRP for short). It looks like you have a lovely BBC (big black cow)

I sure ain't no mechanical expert, but having spent many (un)happy hours fiddling with my Rev-3's ingition in an attempt to solve a persistent engine knock, I can point you in the right direction: Remove the right-side engine cover. You're now looking at the flywheel. To remove the flywheel you'll need a puller - these can be purchased from a dealer or alternatively, make your own as detailed by CharlieC elsewhere in this thread. Once you've got the flywheel off, look closely at the shaft on which it was installed. There's a slot with a small piece of metal sitting in it that locates in a corresponding slot in the flywheel. That's the key and it's fairly common for them to break, causing problems very similar to those described in this thread.

Exhaust packing Seriously, there seems to be 2 different types: The "blanket" stuff that looks like (thinner) loft insulation and the looser "fluff" type. They both do the same job but the fluffy stuff takes a bit more effort. A good tip that I was given a while ago was not to pack it in too tightly - fill all available space but don't ram it in at 60psi. You should be able to buy it from any dealer or try trialsbits.co.uk. Edit: bob, we must both have hit the submit button at the same time!

From the results, it looks more like the "Dougie factor" than a sudden improvement in the 4RT's competitiveness. Unless he had another off day, Fuji's usually a lot closer than that...

I totally agree. I think that now's the time for some forward-thinking production company to resurrect Kickstart for the 21st century - that'd bring trials back into the minds of the general public. What's the reaction of people when you show them a modern trials DVD (especially indoor events) for the first time? "Whoa... that's amazing... " and they're hooked. Isn't trials an exhibition sport at next year's X-Games?

I've been to a couple of enduros where at trials bike would've been the perfect choice! No idea how some of those guys got 'round on 525EXCs and the like. Hare and Hounds = long course motocross. Best description that I can think of!

The enduro bikes are the same, by all accounts. TBM recently reviewed the 2005 EC range and their conclusions can be summarised as "great bikes, crap build quality and attention to detail." I've owned a GasGas in the past (which I spent far more time spannering than riding) and having seen the problems that a couple of my Gasser-owning friends have had, I'd be very reluctant to buy another at this point. Are GasGas a victim of their own success? There doesn't seem to be a supply problem so I can't believe that they're having trouble building enough to keep up with demand and rushing them through QA...