yamafun Posted December 30, 2006 Share Posted December 30, 2006 MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING: IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES. Link to comment Share on other sites More sharing options...
woody_dt175 Posted December 17, 2007 Share Posted December 17, 2007 MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING: IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES. i have a 1992 dt175, can i modify my bike as you have on yours? Link to comment Share on other sites More sharing options...
woody_dt175 Posted December 17, 2007 Share Posted December 17, 2007 MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING: IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES. i have a 1992 dt175, can i modify my bike as you have on yours? Link to comment Share on other sites More sharing options...
blackhat250 Posted February 10, 2008 Share Posted February 10, 2008 MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING: IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES. hi there / noticed u had DT400 1975 . wot colour [black white] or comp yellow. just bought one usa. imported it to uk . rare over here. Link to comment Share on other sites More sharing options...
How2 Posted August 11, 2008 Share Posted August 11, 2008 Greetings: Is there any way to get ALL the specific parts and part numbers for all said items? thanks H2 Link to comment Share on other sites More sharing options...
racerd Posted September 22, 2008 Share Posted September 22, 2008 MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING: IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES. 12000 RPM. MAX RPM IS 13000RPM. this is for the race track on the road 11,000/11,500 spot on, STOCK CYLINDERHEAD BORED TO FIRST OVER = IT175 CYLINDERHEAD MODIFIED ON A LATHE. at what angle was the squish re cut to and did you measure the squish also this lines up the edge to the cylinder bore, CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. what size is the carb now, REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; are both the same meaning, wot = wide open throttle, K&N AIR FILTER. have you oiled the filter also you need the reed block porting and flowing and finishing off in 80 grit production hone marks this aids the mixing of the fuel and oil into the engine taper port the front of the carb open out reed stops inlet port open 360 degree reed block stops and starts flow exhaust port 22mm from top of cylinder liner and make the exhaust port wider as well guide inlet flow towards boost port line up transfer entrances on the barrel to crank cases the ports need a 2mm chamfer at a 10 /12 degree angle flat and polish piston crown and combustion chamber in cylinder head and the exhaust port bigger carb if not using a boost bottle then connect one set squish to 1.00mm Link to comment Share on other sites More sharing options...
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