enduro76 Posted February 23, 2009 Share Posted February 23, 2009 Hello all, I'm new to this forum. I purchased a 1976 dt125 with only 4600 miles and in excellent condition. I enjoy driving it around town. I get a lot of compliments and it's much cooler than a scooter. Is there anything I can do to get a little more power out of the engine? Top speed is currently 55mph if I'm not driving into the wind. With the wind in my face I have to down shift to maintain 40mph. Link to comment Share on other sites More sharing options...
kobascle Posted February 23, 2009 Share Posted February 23, 2009 Hello all, I'm new to this forum. I purchased a 1976 dt125 with only 4600 miles and in excellent condition. I enjoy driving it around town. I get a lot of compliments and it's much cooler than a scooter. Is there anything I can do to get a little more power out of the engine? Top speed is currently 55mph if I'm not driving into the wind. With the wind in my face I have to down shift to maintain 40mph. Get it bored out two sizes over and put in a new piston and rings Link to comment Share on other sites More sharing options...
Twin Shock Posted February 23, 2009 Share Posted February 23, 2009 Hello all, I'm new to this forum. I purchased a 1976 dt125 with only 4600 miles and in excellent condition. I enjoy driving it around town. I get a lot of compliments and it's much cooler than a scooter. Is there anything I can do to get a little more power out of the engine? Top speed is currently 55mph if I'm not driving into the wind. With the wind in my face I have to down shift to maintain 40mph. You could put a 175 top end on it. Link to comment Share on other sites More sharing options...
sezian Posted February 23, 2009 Share Posted February 23, 2009 Why not get the files out and port it !!! Link to comment Share on other sites More sharing options...
enduro76 Posted February 24, 2009 Author Share Posted February 24, 2009 Get it bored out two sizes over and put in a new piston and rings Thanks for the quick response. Any idea how much I would gain by doing this? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted February 24, 2009 Moderator Share Posted February 24, 2009 Not much really and in my view it would be a shame to bore your vintage cylinder to its max if it doesnt need it. Link to comment Share on other sites More sharing options...
Mo®ten Posted February 25, 2009 Share Posted February 25, 2009 Check your intake, exhaust and transfer timing. A skilled tuner can do magic to your engine without killing it. I`ve never checked the timing on a Yamaha engine from the 70`s before so i dont know if they are far away from perfect. Others like my Gilera have totaly wrong timing. Link to comment Share on other sites More sharing options...
little dave Posted February 25, 2009 Share Posted February 25, 2009 my 74 dt is a 2 stroke. the only timing possible is spark timing I think and i'm not quite sure how to do that other than adjusting the points. Link to comment Share on other sites More sharing options...
Mo®ten Posted February 25, 2009 Share Posted February 25, 2009 my 74 dt is a 2 stroke. the only timing possible is spark timing I think and i'm not quite sure how to do that other than adjusting the points. What I`m talking about here is to move the height of the ports where you want it. You could set up the engine to have more power in the middle range for sunday driving or you could set it up for maximum power at the top range for racing. On newer engines there is not mutch you can do, they are already tuned for best preformance from factory, but on older engines you could get a lot of "hidden" power by adjusting (read "grinding") your ports. If you dont know how to do it, DONT DO IT ! Its not that hard, but you could easily make the engine even worse. Link to comment Share on other sites More sharing options...
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