glyph Posted January 14, 2007 Report Share Posted January 14, 2007 Hi All I'm new to this forum so first of all a big hello to everyone and thanks to everybody that has posted in this forum, I've found some really useful information. Secondly, I've just baught my first bike, a Beta Rev 3 270cc 2000 model. When I got it I didn't know much about it, and thought the gearbox oil was the engine oil, not knowing the oil needed to be mixed with the petrol I filled it up with pure petrol You can imagine my horror when I realized that 1/3 of the way down the manual from the beta website changes to English and says that the oil needs mixing with the petrol. So, Foolishly, without any precision, I poured a little oil into the tank. Anyway, I took the bike out today and after trying to hammer it up a really steep, slippy hill it started back firing, flames coming out of the exhaust and turning the throttle has little to no effect. Could it be the mixture that has caused this, perhaps the wrong oil, or does anybody think it might be something more serious and if so, what? it doesn't seem to be smoking anymore than what I would consider normal if it makes any difference. thanks Glyph Quote Link to comment Share on other sites More sharing options...
lineaway Posted January 14, 2007 Report Share Posted January 14, 2007 Drain the fuel tank and the carb. Mix up a fresh batch of fuel, also try a brand new plug. If that does not cure it, remove the flywheel and check to see if the woodruf key is sheared or not. Also do a search on this forum for Beta stators and the like. Hopefully you just fouled a plug. Good Luck. Quote Link to comment Share on other sites More sharing options...
useless Posted January 14, 2007 Report Share Posted January 14, 2007 you say you added oil to the tank, am i right in thinking you added two stroke oil and not engine oil!!!!! Quote Link to comment Share on other sites More sharing options...
glyph Posted January 14, 2007 Author Report Share Posted January 14, 2007 Hi, thanks for the advice. Yeh, it was 2-stroke that I added lol, it's just that I didn't add a specific quantity. I hope it's just the mixture that caused it. I'm thinking that the petrol in the bottom of the tank, fuel lines and carb, i.e. before I added my own concoction, would have been fine which allowed it to run for a short time. Then, when my own brew got through, it gave up the will to live. I don't know how quickly the old and new petrol would have mixed together in the tank so whether or not this is possible is debatable. Also, is it feasible that the flames could have been caused by the mixture being too lean? Looking at the manual, a lean mixture could be the cause of the other symptom; the engine loosing power. As for the woodruff and stator, to be honest I have no idea what they are, but reading through the posts on here it would seem that they are a common problem with Betas. Can I ask what the purposes of the Woodruff and the Stator are? They don Quote Link to comment Share on other sites More sharing options...
bob Posted January 14, 2007 Report Share Posted January 14, 2007 The oil is mixed in with the fuel to stop the engine siezing, it lubricates the main bearings, big and little end and the piston. Hopefully your bike hasn't siezed, or done any permanent engine damage, how long did you run it for without any oil in the fuel? The fuel and oil should be mixed at around 70:1 or so, that being seventy parts fuel to one part oil, or 70cc of oil in 5 litres of petrol. The symptoms are charachteristic of a stator damaged by corrosion which causes erratic ignition patterns, or a sheared woodruff key. The woodruff key slots onto the end of the crankshaft to use as a guide when you place the flywheel, if this shears the the flywheel may slip round on the crankshaft and mess up the ignition timing, so it could be this also. With the beta it is a good idea, in fact you must remove that plastic flywheel cover after you've been riding the bike to let any condensation or water out. Bob Quote Link to comment Share on other sites More sharing options...
the addict Posted January 14, 2007 Report Share Posted January 14, 2007 Glyph, I would be amazed if you haven't nipped it up mate, the fuel probably did nt mix very well in the tank and has leaned out the motor. The flames may be from burning all the ***** in the exhaust system plus setting fire to the silencer packing. The loss in power does sound like its nipped up though, take the plug out and see what it looks like. If its white or looks like its been corroded (missing metal) it has been running way to hot. Repack the silencer, stick new fuel/oil mix in, change the plug and see what happens. Try 75-80mil of good 2 stroke oil (Repsol,TTS etc) with 5 litres of super unleaded. Hope it hasnt done any damage and it runs ok next time Quote Link to comment Share on other sites More sharing options...
paul w Posted January 14, 2007 Report Share Posted January 14, 2007 it sounds like a "top off" to me, just for peace of mind i would want to check the piston to make sure it has'nt nipped. there is a fine line with the lubrication on two strokes, jet rich and you can get away with a slightly leaner oil ratio. jet spot on or slightly leaner, then the oil mix has to be spot on , with a good quality oil. i have recently re-built a 200 ktm , good fuel mix but very low on gearbox oil, it nipped the mains but the barrel was ok, as i say its a fine line. Quote Link to comment Share on other sites More sharing options...
glyph Posted January 14, 2007 Author Report Share Posted January 14, 2007 (edited) Sorry, I don't know what you mean by nipped? It's my first bike so don't know much about bike engines. Are you suggesting that a valve has hit the piston? Incidentally, it's just had an oil (gearbox) change Edited January 14, 2007 by Glyph Quote Link to comment Share on other sites More sharing options...
the addict Posted January 14, 2007 Report Share Posted January 14, 2007 (edited) Glyph, you have nt got any valves to worry about on the Rev3 hitting the piston, nipping up is usually the term for seizing the bike up to varying degrees, sometimes it can be easily repaired depending on how bad the barrell has been damaged,piston rings,bearings etc. Try all the other changes first like new fuel mix,spark plug etc and if it is still not running or running badly you will have to take it to dealer to get sorted. The clutch oil will have had no effect to the running of the bike at all, new or old Edited January 14, 2007 by Betarev3 Quote Link to comment Share on other sites More sharing options...
glyph Posted January 15, 2007 Author Report Share Posted January 15, 2007 Went to the local dealer today to buy some oil. Told him the Make, Model etc and he recommended Castrol R2 Racing Synthetic 2-stroke oil, so at the mercy of the dealer i took his advice and bought that. About to go out and sort the bike, reading through the specs on the back of the oil, it says suitable for ratios up to 50:1, so I'm guessing this is no good and my local dealer doesn't know much about these bikes? He also suggested using 75w for the gearbox/clutch, but reading through the manual on the Beta website, they recommend 20w40 for the 2006 model. Is this the same for the 2000 model or should I listen to the dealer and go with the 75w? As this is a little off topic, I've started a new one: Click here: What oils and additives do you use? Cheers guys (and gals) Quote Link to comment Share on other sites More sharing options...
essex rider Posted January 15, 2007 Report Share Posted January 15, 2007 75w is fine for gearbox just change it a little more often, also the 2 stroke oil you have will be fine what ever mixture you decide to use. Quote Link to comment Share on other sites More sharing options...
bob Posted January 15, 2007 Report Share Posted January 15, 2007 No, if it says up to 50:1 then 70:1 will be fine because this is a weaker mix. Perhaps you should take a little time to understand the workings of a simple 2 stroke engine, it is completely different to the engine you would have on a car, and understanding what is going on may help you to understand what you have done to the engine. As far as oils go, on your bike there is gearbox oil, which you put in the gearbox, rather than just topping up every now and then, this oil should be replaced every four months or so completely, the oil drain bolt is underneath the engine, accessible through a bole in the bach plate. About 500cc of fresh oil is places through a filler hole on the top left of the gearbox just in front of the clutch. Note that slightly less oil than reccomended in the manual should be used because some oil clings to the gears and hangs about between clutch plates. You also have fork oil which needs changing very rarely, it goes in the fork legs and provides damping. Finally you must mix oil in with your fuel, two stroke ENGINE OIL, this lubricates the engine itself, such as main bearings on the crank shaft, the big and little end bearings on either end of the push rod, aswell as the piston/rings. Don't forget to give the bike a shake before starting to mix the oil into the petrol, and never run the bike without oil in the fuel. If you run the bike without engine oil, then nothing lubricates the engine, things wear much more quickly and will get hot more quickly. If the engine has nipped up it is because things have got so hot that expansion has caused it to get too tight to run. In this case you wil be very lucky if the bore (cylinder) has not been scratched, and if the piston rings have also not been damaged. Bob Quote Link to comment Share on other sites More sharing options...
sirhc Posted January 15, 2007 Report Share Posted January 15, 2007 When my Beta's started backfiring and losing power at full throttle it was time to change the plug. They would last three or four months and a new plug would fix it All three of my Betas did this, I thought it was what they all did when they wanted a new plug. Quote Link to comment Share on other sites More sharing options...
glyph Posted January 16, 2007 Author Report Share Posted January 16, 2007 No, if it says up to 50:1 then 70:1 will be fine because this is a weaker mix. Doh! Cheers for the info guys. Shouldn't be a big step from car engines to bike engines right? had a quick look over the externals of the engine, am i right in thinking that because there are no valves to hit the piston, that the piston itself does the same job as a valve would do in a car engine? i.e. when then piston moves down the cylinder, petrol/air enter the cylinder, then the hole is closed again by the piston as it returns to TDC. If that's the case, the same must be said for the exhaust; Now I'm confused, air in --> piston --> air out whilst the piston is down what's to stop the air coming in from the carb shooting straight out the exhaust, and how the hell does it get compression? Sounds like another good excuse to take the "top off" and see what's going on Incidentally, I took the plug out today and all seams to be O.K. Drained the tank, including reserve About to go and replace my unleaded for super unleaded. Will let you all know how it goes. Quote Link to comment Share on other sites More sharing options...
neonsurge Posted January 16, 2007 Report Share Posted January 16, 2007 (edited) had a quick look over the externals of the engine, am i right in thinking that because there are no valves to hit the piston, that the piston itself does the same job as a valve would do in a car engine? i.e. when then piston moves down the cylinder, petrol/air enter the cylinder, then the hole is closed again by the piston as it returns to TDC. Errm, I may be wrong (and please tell me to bugger off if I am) but it sounds to me that you're confusing 4-stroke and 2-stroke engine internals. Your Beta is a 2-stroke which means there are no valves, cams etc. in the head - intake (via a reed valve) and exhaust is taken care of by ports in the cylinder (like you said). Much simpler than a 4-stroke car/bike engine! HowStuffWorks.com has an excellent explaination. If you've been lucky enough not to seize anything with the incorrect fuel mix, I'm still betting on a sheared woodruff key - the symptoms you describe are almost exactly the same as when the key went on my old bike (twice - caused by worn main bearings although that's not necessarily the cause in your case). Either that or the stator plate has slipped somehow and the timing's gone way off. If the stator itself has failed, the bike wont start or run at all in 99% of cases. Edited January 16, 2007 by neonsurge Quote Link to comment Share on other sites More sharing options...
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