Stuckagain Posted February 19, 2021 Report Share Posted February 19, 2021 Just getting to know my 1993 Gara, my first trials bike. Doesn't seem to take much to provoke the carb to start weeing fuel. Seller said they all do that if left with fuel tap on ... or idling ... or just after it's switched off ... or just after I turn the fuel tap on ... or until I turn the fuel tap off... Bike starts, idles and runs fine. This fuel dumping something I just get used to, or is it time for a carb service....? Quote Link to comment Share on other sites More sharing options...
arthritic Posted February 19, 2021 Report Share Posted February 19, 2021 Simple answer, no, unless they are upside down. Check float and float needle. However, if budget allows, a new carb. eliminates a lot of problem searching on older bikes, at least you then know that area is right. Quote Link to comment Share on other sites More sharing options...
reggie Posted February 19, 2021 Report Share Posted February 19, 2021 The stock float needle was a metal to metal type. There is a viton rubber one available that works much better. There are also some set up tips on this forum. Quote Link to comment Share on other sites More sharing options...
lineaway Posted February 19, 2021 Report Share Posted February 19, 2021 http://trialsport.com.au/beta/Manuals/mikuni/ 1 Quote Link to comment Share on other sites More sharing options...
Creepytheclutchmaster Posted February 19, 2021 Report Share Posted February 19, 2021 It probably won't fix your problem because of the age of the carb, you probably have a worn out fuel valve. But my new brand new mikuni vm 26 started permanently p****** fuel the other day. a little trick that found out trawling the Web was to blast compressed air up the overflow pipe clearing out grit or silt stopping the fuel valve closing. I used a can of compressed air as I don't have an air line it worked and my carb has been fine since. Quote Link to comment Share on other sites More sharing options...
Stuckagain Posted February 20, 2021 Author Report Share Posted February 20, 2021 I've cleaned a rebuilt the carb on my 1972 Yamaha DT250 about 500 times. I can't imagine the Gara carb can be any more complicated...? Or can it...? Quote Link to comment Share on other sites More sharing options...
lineaway Posted February 20, 2021 Report Share Posted February 20, 2021 No its not, but ut needs to be set up NOT to leak. Beta used that same carb from 1990 to 2007. Quote Link to comment Share on other sites More sharing options...
misscrabstick Posted February 20, 2021 Report Share Posted February 20, 2021 4 things, dirty tank dumping particles that jam the needle valve open and make it leak, worn float needle and/or seating (common), damaged float (leaking fuel into itself and making it heavy) and finally, incorrectly set float height. Quote Link to comment Share on other sites More sharing options...
Stuckagain Posted February 21, 2021 Author Report Share Posted February 21, 2021 Right, it looks like the leak is from the joint between float bowl and carb body. Gasket I presume. Of course, I can't get hold of any parts people at this time on a Sunday, so does anybody know if the VM26-208 float bowl gasket is the same as other VM26 gaskets? Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 21, 2021 Report Share Posted February 21, 2021 5 hours ago, Stuckagain said: Right, it looks like the leak is from the joint between float bowl and carb body. Gasket I presume. Of course, I can't get hold of any parts people at this time on a Sunday, so does anybody know if the VM26-208 float bowl gasket is the same as other VM26 gaskets? Yes the -208 is just the OEM designation for jets and screws but the float bowl should be the same. As for Mikuni piddling fuel see the pinned thread at the top of the forum. Quote Link to comment Share on other sites More sharing options...
Stuckagain Posted February 21, 2021 Author Report Share Posted February 21, 2021 OK, two big wins today. I'm only an occasional mechanic - and the Beta certainly doesn't have the sort of no-nonsense accessibility my old Yamahas have - but I now have a bike which doesn't have clutch drag from start up after I drained and refilled it with Putoline Nano tech transmission oil, and the carb is no longer leaking. After eventually wrestling the Mikuni out I discovered one of the float bowl screws was finger tight. There was a teeny bit of gunk in the bowl and around the carb which I blasted away with compressed air, but now it doesn't even leak after ten minutes standing with the fuel tap left off. All I need to do now is build up my left leg muscle: it's like trying to kick start a 1958 BSA. 2 Quote Link to comment Share on other sites More sharing options...
Goudrons2 Posted February 24, 2021 Report Share Posted February 24, 2021 (edited) i started my relationship with Beta in 1991 with a Zero (which ended in 2016 with an Evo) and I loved the Zero, though they do have some flaws. I made some posts a while ago on the Zero/Gara but somehow lost my login. As already stated, the carb and engine is quite fussy to fuel level in the carbs float bowl. This needs setting quite precisely otherwise it'll dribble out or flood the engine (too high) or lean the engine out (too low) especially when the bike is inclinded one way or the other. Probably not worth it now but they run miles better on a Dellorto. It's common practice to drain the float bowl after use as modern fuels tend to gum up if left in there for too long and Beta's tend to like the higher octane fuel (98), they can predetonate and make a racket on regular that some might confuse with serious engine trouble. The clutch is typical Beta, though I seem to remember it being cable rather than hydraulic. They all tend to drag at some point even after years of Beta fiddling they still do it, it's all part of the charm! There was a spate of owners back in the day that cooked their engines, trouble was with the drive to the waterpump. It picks up drive from one end of a shaft on one side of the engine, through a couple of small bearings and a load of small seals, right through all the cases and turns the pump on the other side of the engine. Once the seals go, coolant disappears into the cases pretty quickly. Another weak point is the swinging arm. It can facture across the voids, where the bearings and bushes fit (to the frame). I snapped one clean off and another cracked across the top of both bearings/bushes, the alloy appeared pretty brittle. One final design flaw, the "nut cracker" tank/frame. Just thinking about some of the old hard come downs I had on that makes my eyes water! There are still some parts about for these, though they are getting thin on the ground now. I found a parts diagram a while ago here http://trialsport.com.au/beta/Parts/Zero 93.pdf Edited February 24, 2021 by Goudrons2 Quote Link to comment Share on other sites More sharing options...
Stuckagain Posted February 24, 2021 Author Report Share Posted February 24, 2021 Hi, thanks for that: useful. I'm building an understanding from all this that simply doesn't seem to be available in one place online. After checking and air blasting the innards, then tightening up the fourth screw on the float bowl, there's no leakage at all. Not even if I leave it with the tap turned on. Seems to run the same now as before, but without the petrol smell. I'm not likely to give it a hard time: it's my first trials bike since the 1970s (a TL150) and I'll probably be doing mainly pay & play stuff. I'll be running it on super-unleaded, as I do with a couple of my other old (non-trials) bikes. No signs of overheating. I've been trundling it mainly around the far reaches of my garden. I've not noticed the fan kicking in at any point, but previous owner swears it works. Changed transmission fluid and the old stuff didn't look that old. Putoline Nano went in, and it hasn't so far dragged at any point, although the test will be when I get it fired up tomorrow after three days sitting in the garage. The bike, not me. I saved three days sitting in the garage for my 71 Honda 250. Input much appreciated. Cheers. Quote Link to comment Share on other sites More sharing options...
Vagakai Posted March 27, 2021 Report Share Posted March 27, 2021 Hi! I am rebuilding a Beta Rev3 together with my son, and I need a new float valve assembly for the VM26-208. Can anybody recommend a serious supplier of these parts? Thanks for any help! Quote Link to comment Share on other sites More sharing options...
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