movingtarget Posted July 7, 2006 Report Share Posted July 7, 2006 I seem to be going through a plug a day at the moment. It always happens after about an hour and when accelerating away in 4th or 5th gear. I'd spend most the time in 2nd or 3rd then go onto a road or track in 4th or 5th, accelerate away, at which point it dies. The plugs always look black and slightly suity. I can't figure out what it could be... Anybody know what could be the problem? The engine always seems fine up until the point it dies. Quote Link to comment Share on other sites More sharing options...
fellonmelug Posted July 7, 2006 Report Share Posted July 7, 2006 Sounds like its running a bit rich, check air filter give the carb a good clean out , what oil are you running on ? make sure ratio is ok Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 7, 2006 Author Report Share Posted July 7, 2006 I'm using 75ml of Putoline trial tt pro to 5 litres petrol. I'll give the carb a clean and check the air filter though. Do you reckon there is not enough air getting through? I know adding oil to the air filter wouldnt help the situation if thats the case but last time I checked it was pretty dry, whats the best way to oil it up? cheers Quote Link to comment Share on other sites More sharing options...
phb Posted July 7, 2006 Report Share Posted July 7, 2006 (edited) i run a beta 250 o5 model and have been told not to use oil on the air filter but WD40 and have always done this and it runs really good, when i used proper filter oil i found it run very rich Edited July 7, 2006 by PHB Quote Link to comment Share on other sites More sharing options...
billyt Posted July 8, 2006 Report Share Posted July 8, 2006 (edited) Movingtarget You are not fouling the plugs but Poping them. Basically the plug is getting to hot breaking down its insulation causing it to lose spark power. Nothing to do with oil ratios or filter. The bike is too lean in the carburation. What pilot and main jet are you running? Have you set up the carb per my specs? As you may be going in to a lean condition due to low fuel levels at higher RPM's..... Trust me on this as I have seen it many times that people do not understand the difference between a "fouled plug" and a "Popped plug". Fouled is due to rich carburation or too more filter oil. A popped plug is mainly due to the carb jets beeing to lean or fuel levels dropping at higher RPM's or even to much oil in the gas which can believe it or not cause a lean condition. Let me know how you get on. BillyT Edited July 8, 2006 by BillyT Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 8, 2006 Author Report Share Posted July 8, 2006 Many thanks for the responses. BillyT I've tried looking for the size of the jets but couldnt find any numbers. Other than thoroughly cleaning the carb what else could I do? Quote Link to comment Share on other sites More sharing options...
the addict Posted July 8, 2006 Report Share Posted July 8, 2006 Moving Target The 06 - 270 has 30 pilot and 150 main as standard, the numbers are very very small but should be on them, cant be sure if the 04 runs the same jets though Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 8, 2006 Author Report Share Posted July 8, 2006 Betarev3 - Thanks will have another look later. BillyT - I adjusted the tangs so that they point to the top of the pilot jet when upside down, although your second adjustment i did not understand how far to adjust the tab, 1/16th? how far is this and from which point? The vent hose on the back of the carb had been pressed against the exhaust, and had actually melted shut, so I cut it off about an inch from the carb. This shouldnt affect it too much should it? I also still need to cut them at a sharp angle. One other thing I noticed is that the colour of the petrol in the carb looks a stronger blue than when it is just mixed, plus there is traces of this stronger blue underneith the carb where it has leaked. At least I think its more blue than it should be, it never looks that blue when i'm pouring it in. Could this mean the oil is seperating from the petrol? I always give the can a good shake before filling the bike, but I cant exactly give the bike a good shake if its been sitting put for a couple days! Quote Link to comment Share on other sites More sharing options...
billyt Posted July 8, 2006 Report Share Posted July 8, 2006 (edited) Are you sure it is a Mikuni carb and not something else that some one has switched out? The jets have to be taken out to read the numbers. As for the colour of the petrol I pressume that you are in the UK since you are calling it petrol and not gas? The colour may be fine if the petrol is always that colour. The oil should not be seperating if you are using a good quality pre mix oil. When I say a 1/16 movement I am stating that one should not be able to move the tang more than a 1/16 when lifting and dropping it. You are tying your self in knots here for no reason. Tell us the sizes of jets you have in the carb first and we can help. Keep in mind that the air fuel ratio gets leaner when the bike climbs in rpm's so it can pop a plug if the jets are to lean. Because a plug is black and sooty it does not mean that the bike is too rich. The bike can be running rich at the bottom rpm's placing excess oil on the plug but at higher rpm's in may be way to lean causing the insulation to go. You pull out the plug look at it and beacuse there is oil on it one assumes that it was fouled but in actual fact the oil from the rich condtion has nothing to do with the lean at the higher rpm's, very missleading to a novice weekend mechanic. BillyT Edited July 8, 2006 by BillyT Quote Link to comment Share on other sites More sharing options...
dale Posted July 8, 2006 Report Share Posted July 8, 2006 The dark blue colour you mention under the carb/leaks is only the 2 stroke oil after the petrol has evaporated away Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 8, 2006 Author Report Share Posted July 8, 2006 (edited) It is definetly a mikuni carb, and looks identical to the photos on the r2w website where you're setup is. I've set the higher and lower travel of the tangs and the hoses have been cut as you suggest, except the one at the back is still short. At the top of the highest tower, which I'm assuming it the main jet, is written 150. Is the pilot jet sunken a cm or two inside the hole next to it, and extracted with a screwdriver? If so I dont have a screwdriver to fit it and will have to wait a day or two till I can borrow one that fits... About the weekend mechanic thing, I have no choice. I live in the middle of nowhere, and my only transport is by bike so I cant get the bike to somebody that knows what they're doing without help Edited July 8, 2006 by MovingTarget Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 8, 2006 Author Report Share Posted July 8, 2006 (edited) Ok will check those, although what exactly are the reed valves? One thing I also did today was change the clip on the needle(that sits inside the very top of the carb) back to the middle setting. Couple months ago when some mechanics were sorting my bike out they moved the clip up one place, moving it back down will increase the flow of petrol? Could that possibly be one of the causes? One other thing I should mention, I might have said it before some place, the fan only comes on very briefly after a lot of revs, it doesnt seem to work unless the engine is very very hot. Many thanks for the help Edited July 8, 2006 by MovingTarget Quote Link to comment Share on other sites More sharing options...
jonty Posted July 8, 2006 Report Share Posted July 8, 2006 Moving Target, unless I've missed it somewhere you don't seem to have mentioned which make and model of spark plug you're using. This information could help identify the problem. Regarding the cooling fan situation Betas definitely seem to take longer for the fan to cut in than other makes and this is'nt necassarily a problem. Quote Link to comment Share on other sites More sharing options...
movingtarget Posted July 9, 2006 Author Report Share Posted July 9, 2006 The last 5 spark plugs I've used have been either NGK BP5ES or NGKR BR6ES. Will check all the things mentioned in the next couple days, wont be able to try it out until I get more plugs which will be at least 2 days. This next week is my holiday and all I wanna do is ride! Patience is not my strong point Quote Link to comment Share on other sites More sharing options...
jonty Posted July 9, 2006 Report Share Posted July 9, 2006 Moving Target, Unfortunately patience is what you you need most right now as it's down to a process of elimination! Quote Link to comment Share on other sites More sharing options...
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