borus Posted February 16, 2008 Report Share Posted February 16, 2008 has anyone bumped up their 2.5 to a 2.9 adding a cylinder/piston etc. i took a look at the parts book (1999/2000) but it's not that clear on separating them and seems to only mention the 2.5 with a part number. any input or thoughts apprciated. btw, i don't believe there was a 2.9 that year so i'd be looking at a later 2.9 year. just looking at upgrading over purchasing something newer. cheers Quote Link to comment Share on other sites More sharing options...
honda_tlr Posted February 17, 2008 Report Share Posted February 17, 2008 Yes it can be done. Quote Link to comment Share on other sites More sharing options...
dabdab Posted February 19, 2008 Report Share Posted February 19, 2008 Certainly can be done. I did it back when the first 290 came out but I was never happy with the result-the modified bike just didn`t seem the same as the new 290. More power, but somehow rougher in running. I think there a few minor mods between the basic engines that Sherco forgot to mention The bike is long gone, but I still have the 250 barrel, piston and cylinder head of the 250 ( Graeme Jarvis Special ) Current bike is an 03 Sherco with later model header pipe, thicker inlet spacer, changed pilot jet, Twin Air filter and modified timing. Smooth as a baby`s bum. ( I am an old school rider after all ) despite the softening of power, the 03 290 still packs a bite as I can certify after my efforts at the Australian Masters Games, when a bit too much oomph up a creek bank left me with a wrenched right thumb tendon and bruises to body and ego. Quote Link to comment Share on other sites More sharing options...
copemech Posted February 20, 2008 Report Share Posted February 20, 2008 Certainly can be done. I did it back when the first 290 came out but I was never happy with the result-the modified bike just didn`t seem the same as the new 290. More power, but somehow rougher in running. I think there a few minor mods between the basic engines that Sherco forgot to mentionThe bike is long gone, but I still have the 250 barrel, piston and cylinder head of the 250 ( Graeme Jarvis Special ) Current bike is an 03 Sherco with later model header pipe, thicker inlet spacer, changed pilot jet, Twin Air filter and modified timing. Smooth as a baby`s bum. ( I am an old school rider after all ) despite the softening of power, the 03 290 still packs a bite as I can certify after my efforts at the Australian Masters Games, when a bit too much oomph up a creek bank left me with a wrenched right thumb tendon and bruises to body and ego. Although my perception is muchly degraded over time, I seem to recall the older 2.5's to be some of the smoothest and best around. Specially the '00 model i think it was. Having done much the same things to the '03 2.9 and still finding it a handfull at times, I would be realy inclined to put that old 2.5 top on her as you may be surprised just how good it really is for the normal rider! Nobody will ever know! Quote Link to comment Share on other sites More sharing options...
neo Posted February 20, 2008 Report Share Posted February 20, 2008 I would be realy inclined to put that old 2.5 top on her as you may be surprised just how good it really is for the normal rider! Nobody will ever know! I second that motion!! borus, I think you'd be better spendig your money on a PWK 28 Carby. Or Leonnie ignition system, than messing around with the barrel. Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
borus Posted February 20, 2008 Author Report Share Posted February 20, 2008 I second that motion!!borus, I think you'd be better spendig your money on a PWK 28 Carby. Or Leonnie ignition system, than messing around with the barrel. Best of balance. Neo thanks all for your responses, when i did a search of the forum i couldn't find anything being discussed on this subject, it's something i may consider after tinkering with many other things as neo points out, being an older bike which happens to be the first model year and with 9 years of improvements/changes that have been done to the model it's interesting to imagine what i may do in the future to suit my riding. i'd still be interested on more thoughts, engine or otherwise on improvements to the original model. outside of a few cosmetic blemishes this bike is still fresh as it's seen about 12 trials and very little practice time and sat in the garage of it's original owner so there's definitely some potential here. cheers Quote Link to comment Share on other sites More sharing options...
dabdab Posted February 20, 2008 Report Share Posted February 20, 2008 Sorry Copemech but I must clarify something. Firstly my 1999 Graeme Jervis special was not as smooth as other 250s I rode. Period. Dont`t know why, but it was. Having ridden a lot of the 1999 250s, I can also say there seemed to be a lack of consistency in riding characteristics. Some of them could not be ridden old style ( sans lots of clutch action ) and did not seem to hold tuning The 03 290 is just fine, after the mods, and thanks for your concern. May I bore you with the real story-I ride the Masters Games in the Over 60 Twin Shock class on a M199A Sherpa. The Masters Games is every 2 years, and in the second of those 2 years I ride the Sherpa only in Club and Open to get used to the power characteristics. The Sherco stays in the shed for that year. A week before the Games this year, the Sherpa went into dry dock. I was forced to change class ( up against a younger class ) and bike, and ride different lines in the sections. To cap things off, the Sherco had a brand new tyre, lots of grip. No time to practice ( what is practice anyway-the first lap?) I was into only my seventh section at the time of disaster. It was just a lack of concentration and lack of relevant familarity. It was not the bike mate, just the idiot at the helm Quote Link to comment Share on other sites More sharing options...
copemech Posted February 21, 2008 Report Share Posted February 21, 2008 Sorry Copemech but I must clarify something.Firstly my 1999 Graeme Jervis special was not as smooth as other 250s I rode. Period. Dont`t know why, but it was. Having ridden a lot of the 1999 250s, I can also say there seemed to be a lack of consistency in riding characteristics. Some of them could not be ridden old style ( sans lots of clutch action ) and did not seem to hold tuning The 03 290 is just fine, after the mods, and thanks for your concern. May I bore you with the real story-I ride the Masters Games in the Over 60 Twin Shock class on a M199A Sherpa. The Masters Games is every 2 years, and in the second of those 2 years I ride the Sherpa only in Club and Open to get used to the power characteristics. The Sherco stays in the shed for that year. A week before the Games this year, the Sherpa went into dry dock. I was forced to change class ( up against a younger class ) and bike, and ride different lines in the sections. To cap things off, the Sherco had a brand new tyre, lots of grip. No time to practice ( what is practice anyway-the first lap?) I was into only my seventh section at the time of disaster. It was just a lack of concentration and lack of relevant familarity. It was not the bike mate, just the idiot at the helm Funny thing that story brings back a distinct memory of my '03 bike! There was a local practice area I went to before they closed it, had a nice little rocky creek crossing on the trail that had a good double step about 4ft high that I had crossed probably 100 times prior. But returning ond day after a good workout in the back sections the normal little blip up the steps left me sitting on my backside on the top before I knew what happened! Gave me a new respect for that bike! Quote Link to comment Share on other sites More sharing options...
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