jimsshed Posted January 16, 2006 Author Report Share Posted January 16, 2006 Thanks KTMSprocket. We've been away for a long weekend, hence the slow reply, but I'll have to contact my Beta dealer again and get this sorted out. I will let the forum know what happens. Cheers, Jim Quote Link to comment Share on other sites More sharing options...
ktmsprocket Posted January 16, 2006 Report Share Posted January 16, 2006 Good luck.... Quote Link to comment Share on other sites More sharing options...
peterhindley Posted January 20, 2006 Report Share Posted January 20, 2006 Hi. I have EXACTLY the same problem. Engine idles high for about 20 seconds then dies. Mine has brand new piston, ring and crank seals, so it can't be compression or a crankcase air leak. It feels to me as if it is wanting more fuel right at the bottom, but with the crappy SHA carb, you have limited adjustment. I will try replaceing the "Jet" for a larger one this weekend and see what effect it has. Failing that, I have a TY50 carb somewhere which might go on and allow me to adjust the circuits individually. One thing I have learned is that the small drilling which feeds the base of the "emulsion tube" with air is easily blocked, and can't be blown out. As much as I hated to, I ended up poking a bit of wire into it to clear. Watch this space. Peter Quote Link to comment Share on other sites More sharing options...
jimsshed Posted January 20, 2006 Author Report Share Posted January 20, 2006 Peter, did the bike run okay before the new piston etc, or did you just acquire it? For my part, I have returned the bike to the dealer for a refund, and he will in turn return it to the importer. My last ditch debug effort before returning it was to remove the reed valve block. The reeds were seating perfectly. I did notice that the machined crancase facing which the reed block bolts into had a slight surface mismatch where the two crancase halves come together...maybe 0.25mm. There was no visual evidence of intake manifold gasket leaks though. This mismatch could also be felt by running my finger around inside the intake, although this is a bit moot because the internal surfaces aren't machined. On reassembly I chose not to seal the gaskets with a sealant (there was none applied at the factory) because by now I was now fed up with the whole thing and didn't want to tamper with it's original build. Just one more observation...the crancase halves had no gasket between them. This is normal, but I saw no evidence of sealant anywhere. Always when you reassemble two crankcase halves, you get at least SOME sealant being squeezed out. I could be wrong, but I can't remember seeing or feeling any when I was running my finger around checking the mismatch. We've now ordered a Gas Gas TXT 50 Boy. Consequently we may never know what the problem truely was. Regards, Jim Quote Link to comment Share on other sites More sharing options...
ktmsprocket Posted January 21, 2006 Report Share Posted January 21, 2006 The KTM 50cc engine uses a crankcase gasket. Part No. 45130039000 ENGINE CASE GASKET 50 LC 2001 If you go to say www.50ccparts.com and click on the link to get to KTM parts and follow your nose, you will find the part. As I don't have that bike and have not seen one I can't say 100% it is the same motor....but from photos....it looks the same. Can anybody confirm that this is the Beta AC or LC 50cc 3 shoes clutch motor??? If it is...that seal was not installed at the factory. All very odd... Quote Link to comment Share on other sites More sharing options...
neashfella Posted January 23, 2006 Report Share Posted January 23, 2006 Jim, I have a Beta Rev 50 2002 for my son and this does the same thing in that it revs like hell then eventually dies - most of the time anyway. I have had trouble when power washing the thing off and getting water into the filter and carb due to the fact of a pathetic air intake box having 2 dirty great breather holes in it, so this may be worth checking but I would think this was the first thing you looked at if your model is the same. I have tried most things to get a decent steady tickover including a topend decoke, cleaning carb and tank out etc but it hasn't happened. Quote Link to comment Share on other sites More sharing options...
ktmsprocket Posted January 23, 2006 Report Share Posted January 23, 2006 Some insights for you....may help in your thinking... The KTM Mini Adventure engine in stock configuration idles beautifully, but once you put a larger pipe on it, the idle goes haywire. By changing the pilot circuit jet and fiddling with the idle and air screws you can obtain a steady but high idle. By increasing the idle, the centrifugal clutch begins to take up everso slightly. If the bike is on the ground you may not notice this. What then happens is that more fuel poors in, and the engine loads up and causes a minor bog. The bog and high idle work against each other and this can contribute to poor running as the throttle rolls on. If you put the bike on the stand with the engine running, the rear whell will spin if the clutch is engaging at idle. If you add a shim to each spring of the clutch, you will be able to increae the clutch stall speed and this will get rid of the bog. However, the clurch take up may become very slightly more aggressive. The more shims you add, the more aggressive and snappy it becomes. (In the MX config we use spring washers in a stack rather than coil springs). +++++++++++++++ From all of the posts I am getting the impression that the carb fitted by Beta is just plain wrong for that engine/reed/exhaust combo. The other concern is that someone mentioned a missing gasket between the cases halves???!!! If I owned one (and because I have the stuff in the workshop), I'd fit the KTM MA carb, reeds etc and see how it went... Hmmmm Quote Link to comment Share on other sites More sharing options...
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