barfy Posted January 20, 2015 Report Share Posted January 20, 2015 Three weeks ago my boys Evo 80 had a touch of water in the carb, probably from splashing because he's not dropped it in any water. I cleaned it out at the trial with no problems and stripped it down to blow it out when we got home. Since then it doesn't seem like its revving out cleanly. I didn't note where the mixture screw should be, but it seems to pickup and run best at about 3 1/4 turns out. I've also changed the plug. Someone suggested it might be the rings and seals, but it's only just short of 2 years old and less than 80 hours of schoolboy novice route usage. Any ideas why it might note be revving out cleanly? Quote Link to comment Share on other sites More sharing options...
dadof2 Posted January 20, 2015 Report Share Posted January 20, 2015 (edited) Check the air filter is clean / free of water. Check there is not water in your fuel, you can get condensation problems at this time of year. The cold causes water droplets to form inside the tank, they then get splashed down under the petrol, can't evaporate out again. This causes gradual water build up. Once you have done the above warm the bike up then turn the fuel off, keep the bike running and if it revs cleanly as the carb runs out of fuel it means there is something amiss in the carb, possibly float height, dirt in float valve or a jet in loose. Slow running screw is very unlikely to affect revving out. Rings and seals very unlkely Edited January 20, 2015 by dadof2 Quote Link to comment Share on other sites More sharing options...
barfy Posted January 20, 2015 Author Report Share Posted January 20, 2015 Thanks for the reply dadof2. I cleaned and blew it out again tonight. The air filter also went through the washing machine with the riding kit. I'll drain the fuel out of the tank and put in fresh just in case it's got water contamination. Then see how it goes this weekend. If there is still a problem I'll try as you say with switching off the fuel. Glad that you think rings and seals are unlikely as well. Quote Link to comment Share on other sites More sharing options...
barfy Posted March 8, 2015 Author Report Share Posted March 8, 2015 It's taken hell of a while fiddling to get my lads Beta 80 running well and in the end it was such a simple fix that I needed to update this thread. I'd seem to get it fixed, then it'd struggle on one section during a trial, so back to the drawing board. However, I changed the air filter during the week from a Twin Air to original Beta. Now it seems to be running well again. So I can only conclude that the Twin Air filter was a bit thicker than the Beta one and restricting air flow!! Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted March 8, 2015 Report Share Posted March 8, 2015 I don't know what heat you do the washing at but it is conceivable that, if too hot, then the foam could be damaged such that the pores close up? I've discovered No Toil which makes cleaning and oiling dead easy with no chemicals etc required for cleaning. 1 Quote Link to comment Share on other sites More sharing options...
barfy Posted March 8, 2015 Author Report Share Posted March 8, 2015 Spoke to the person who drives the washing machine and she said she washes the trials stuff at 40 degrees. Means nothing to me :-) I've been on tin-ter-net and ordered some No Toil for cleaning the filter in future. Cheers. Quote Link to comment Share on other sites More sharing options...
dan williams Posted March 9, 2015 Report Share Posted March 9, 2015 I've never heard of putting an air filter through the wash. I'd be afraid of four things; Detergent affecting the filter foam. Heat affecting the filter foam. Especially if it goes through the dryer. Other things in the machine mechanically tearing the filter apart. Coating everything washed in the same machine from then on in a fine coating of air filter oil. I always hand wash, some times with a mechanics hand soap to break up the oil. Rinse thoroughly to make sure none of the soap remains. Rinse again and hand wring in a paper towel. Re-oil and reinstall. Quote Link to comment Share on other sites More sharing options...
lineaway Posted March 9, 2015 Report Share Posted March 9, 2015 It also could be the condition of the exhaust. But I have seen bikes that a change of the filter does do this, especially on such a small engine. Quote Link to comment Share on other sites More sharing options...
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