Yamahdan Posted March 11, 2013 Share Posted March 11, 2013 Hi all, DT was running majorly lean from when I bought it so after a month of riding it melted the exhaust side of the piston, grey/white deposits in the engine etc, needless to say the barrell took a beating, I want to keep the rebuild as cheap as poss so want to rebore. I have found a couple of companies but not sure of the quality of their work.. I have all the ability at work to machine the bore oversize but not to hone it ( don't have a hone big enough ), I also have the ability to measure it all to the Nth degree, which I intend to do after the job is done. I don't mean to sound anal about it but I want to get the job done right because I want the most out of the DT. So could anyone recommend a trusted service ( preferably in Kent ) who I could talk to about doing a re-bore on the DT? Thanks Danny Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 11, 2013 Moderator Share Posted March 11, 2013 If you can bore it yourself do it. The hone just roughs up the surface like sanding wood to apply paint. So long as you use a boring bar shouldn't be an issue. Are you sure the bottom end is ok. My dt ate its piston earlier in the year and the swarf got everywhere. Seals bearings all toast. Even splitting the cases caused the stuff to spread into the bloody gearbox. Link to comment Share on other sites More sharing options...
Preload Posted March 11, 2013 Share Posted March 11, 2013 Rob Pemberton at Skellerns M/C's a 2 stroke barrel boring expert. Link to comment Share on other sites More sharing options...
blackhat250 Posted March 11, 2013 Share Posted March 11, 2013 Grampian Engineering [ Liverpool] . remember and find the cause of the heat seizure, air leak or wrong jetting, Link to comment Share on other sites More sharing options...
Yamahdan Posted March 14, 2013 Author Share Posted March 14, 2013 Thanks for the replies, If you can bore it yourself do it. The hone just roughs up the surface like sanding wood to apply paint. So long as you use a boring bar shouldn't be an issue. Are you sure the bottom end is ok. My dt ate its piston earlier in the year and the swarf got everywhere. Seals bearings all toast. Even splitting the cases caused the stuff to spread into the bloody gearbox. You're right, It does have a massive affect on surface finish (rough it up) but it also gives the bore very good geometry, i.e. Roundness and straightness, which when boring will be crap, due to running an interrupted cut over the ports, and as I'm looking to use the bike to basically out-run all of my mates at enduro's I want it to be running spot on without coughing up for a new cylinder!! As far as the bottom end goes I haven't stripped it yet, I've literally whipped the head, barrell and piston off to see what the crack is... There is play on the conrod so its getting stripped down to nothing anyway to rebuild this, when it comes apart I'll see whats happening in the bottom. Grampian Engineering [ Liverpool] . remember and find the cause of the heat seizure, air leak or wrong jetting, I believe I know why it was running lean, I intend to replace all bearings and seals anyway so air leaks will be eliminated, I'm going to knock up a "crankcase vacuum tool" before I strip it to see if it was this. However I do know that it is seriously under-jetted, its "rockin" a full DEP system with a 210 jet not a good idea, grey deposits all over the top and underside of the piston (whats left of it) as well as the spark plug! Thanks again Danny Link to comment Share on other sites More sharing options...
jimmythemoonlight Posted March 15, 2013 Share Posted March 15, 2013 i am bored of this topic Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 16, 2013 Moderator Share Posted March 16, 2013 i am bored of this topic are you honing your jokes here? Link to comment Share on other sites More sharing options...
Moderator mervin Posted March 16, 2013 Moderator Share Posted March 16, 2013 Try contacting http://www.tsrvapourblasting.co.uk/ he know of a good shop for rebores in Kent, Stan Stephens would be good but it is just about impossible to get anything done by him nowadays cos he is so busy Link to comment Share on other sites More sharing options...
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