stuessenhigh Posted March 16, 2008 Report Share Posted March 16, 2008 Hi all, Well..I've just taken the barrel off my 02 Beta Rev3 250. Mostly because last time I rode it, it was making a strange rubbing noise from the top of the engine. I thought one of the rings might have broken or something and also assumed it was time I changed the piston rings anyway. SO..the barrel is off, and all looks well on the inside, but just wondered if any of you had any tips for cleaning the top of piston..(whats the best thing too clean it with). Also, ..should the arm? that holds the piston be a brown colour. Its almost a rusty kind of colour...not what I expected. Sorry if any of this is vague. First time I've taken the head of ANY bike!! Thanks for any advice you might be able to give. Quote Link to comment Share on other sites More sharing options...
dan williams Posted March 17, 2008 Report Share Posted March 17, 2008 It's not uncommon for the hot internals like the connecting rod to collect a kind of varnish from the unburned but well cooked oil that accumulates on them. It won't hurt anything, just ignore it. I assume you've taken the piston off of the connecting rod. I use a Dremel tool with the wire wheel to clean carbon from the top of the piston and head. A little degreasing hand cleaner added is a bit messy but will polish it up nice. Use light pressure as you're trying to degunk and knock off carbon not score the aluminum. Be patient and take your time. Once done flush it off with water after to make sure there are no residual carbon bits or pieces of the wire wheel in the nooks and crannies. You also want there to be no residual degreaser. Remember safety glasses. Especially with the little wire wheels since they are prone to flinging off pieces of wire. You shouldn't need to go near the sealing surface of the head with the Dremel. Let me re-phrase that. Don't go near the sealing surface of the head with the Dremel. Use a broken ring to chase any debris in the ring grooves. Don't take the Dremel to the ring grooves either because if you change the shape of the bottom of the groove you might as well not put a ring in. My experiance with Betas is that after 4 years of use the rings get a bit tired and the first symptom is it's a little harder getting the bike to fire up in the morning. The fall off in power is so gradual you really never notice it until you replace the rings. Once you do you'll think you have a new bike. Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted March 17, 2008 Author Report Share Posted March 17, 2008 Thanks Dan, Thats all really usefull stuff, and thanks for taking the time to type it all out. I'm looking forward to that new feeling which I hope to get when I've finished it all and have the new rings in. Just ordered a new base gasket today as well. Didnt order the top gasket (metal one) since it seemed absolutely fine. If anyone thinks that was a mistake please say and I'll order one ! Cheers. Quote Link to comment Share on other sites More sharing options...
gez Posted March 18, 2008 Report Share Posted March 18, 2008 A safer way stew is just to use wd40 and a saucepan cleaner (scouring pad) you can,t damage the piston this way Quote Link to comment Share on other sites More sharing options...
jezza Posted March 18, 2008 Report Share Posted March 18, 2008 Get a new metal gasket you cheap skate. Even though it looks ok it will have compressed slightly when it was used before. That is why it is there. Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted March 19, 2008 Author Report Share Posted March 19, 2008 Cheers again all.. Heath..yeah, sorry I may have forgotten to tell you. No I havent sold the 05 but I bought back my 02..(first trials bike I had)..purely for sentimental reasons. Pleased I did too coz on the ride I had before starting to strip it down it was great, apart from the engine noise, which is why I decided to take a look. More soon. STU Piston is all clean now, but still trying to get remnants of old base gasket off that are stuck on the base...(any tips for that??) Quote Link to comment Share on other sites More sharing options...
gasgasthermo Posted March 19, 2008 Report Share Posted March 19, 2008 you might as well pop a new little end bearing in whilst you have the top end off. Quote Link to comment Share on other sites More sharing options...
andy m Posted March 19, 2008 Report Share Posted March 19, 2008 Hi Stu, stuff the crankcase mouth with kitchen towel / similar and carefully using a stanley blade peel the bits of base gasket away being careful not to gouge the alloy of the casings. May be an idea to use a used blade if it is not too stubborn. When it's all spotless carefully remove the towel with any bits of gasket you have managed to catch. Oh and always use a new head gasket you tight a***. Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted March 20, 2008 Author Report Share Posted March 20, 2008 Well...you know us Herefordians...we're tighter than the Scots and Yorkshiremen put together, but I better not get saying that on here eh! Thanks for the advice though Andy. I had wondered about the bearing, so thanks for that advice too gasgasthermo. OK..better get back to the garage. Hope I might see you in Apperley (Cheltenham Spa comp) on Monday morning Andy...its just before Tewkesbury, so not too far for us. Quote Link to comment Share on other sites More sharing options...
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