shntat Posted December 12, 2011 Share Posted December 12, 2011 is it posible to fit a dt400 engine on a dt175 frame if so how much work needs to be done? Link to comment Share on other sites More sharing options...
littlej Posted December 12, 2011 Share Posted December 12, 2011 I think it was Drewpy who said it in a previous thread. "You can make any engine fit into any frame if you have the cash" Link to comment Share on other sites More sharing options...
blackhat250 Posted December 12, 2011 Share Posted December 12, 2011 Why would you ? be better wth a Yz 250 engine out of a motoX er, lighter and more poke.. Dt 400, - is only 32 bhp. ,, CDI needed as well, Link to comment Share on other sites More sharing options...
Paulwhite Posted December 13, 2011 Share Posted December 13, 2011 plus you need to consider that ur putting a 400cc engine with so many torque into a 175 frame designed to only take so much stress. id have to agree and say ur best bet for safety and wheight (plus power ect) would be to go to a 250cc motor. you can put any engine into any frame but its allot of work, you need to be able to make or get hold of custom mounts, make a new loom following a diagram, then there is a space issue, will the exhaust fit? where is the carb/ airbox going to go? is there room for the battery and electronics? then there is the "what if?" factor.....e.g. what if i want to get to the carb to re-jet it, or what if i want a new after,market exhaust. can i get to the air filter and sparkplugs for a service without taking the engine out? all this needs to be considerd, plus you will need to check up and see if you need to do a vosa check by the dvla. then see if you can get insured. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted December 13, 2011 Moderator Share Posted December 13, 2011 I have often thought of an early powervalve motor in my DT, that would be a very easy exercise, just the rad complicating things. The brakes are the biggest issue as they struggle to stop the 175, that is whats always stopped me. By the time you have swapped the motor then the brakes you may as well get something else.. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 13, 2011 Moderator Share Posted December 13, 2011 All valid points, the brakes, the fitting of a physically bigger engine, the bigger carb etc...no room to connect to the airbox, making a new exhaust..blah blah! just not worth the headache Link to comment Share on other sites More sharing options...
shntat Posted December 15, 2011 Author Share Posted December 15, 2011 so it looks like the hard part is fitting it to the frame. i can get the dt400 motor and swap cylinders to make it a 250 the other issue is connecting to the dt175 air box and heat shielding to save oil tank from becoming mush. Link to comment Share on other sites More sharing options...
shntat Posted December 15, 2011 Author Share Posted December 15, 2011 wiring the cdi is also easy most of wires go to the magneto and lighting coil just need to change wire ends between them and connect to 6v system i also noticed the 400 has 8 fins on cylinder and 175 has 6 the exhaust on the 400 is on the left the 400 has a smaller airbox i found a 400 motor on ebay http://www.ebay.com/itm/130611112019?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 motor http://www.ebay.com/itm/140654878295?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 cdi box http://www.ebay.com/itm/330647195999?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 reed box and boot its cheaper than getting a new cylinder,studs,nuts and gaskets Link to comment Share on other sites More sharing options...
shntat Posted December 15, 2011 Author Share Posted December 15, 2011 plus you need to consider that ur putting a 400cc engine with so many torque into a 175 frame designed to only take so much stress. id have to agree and say ur best bet for safety and wheight (plus power ect) would be to go to a 250cc motor. you can put any engine into any frame but its allot of work, you need to be able to make or get hold of custom mounts, make a new loom following a diagram, then there is a space issue, will the exhaust fit? where is the carb/ airbox going to go? is there room for the battery and electronics? then there is the "what if?" factor.....e.g. what if i want to get to the carb to re-jet it, or what if i want a new after,market exhaust. can i get to the air filter and sparkplugs for a service without taking the engine out? all this needs to be considerd, plus you will need to check up and see if you need to do a vosa check by the dvla. then see if you can get insured. battery , electronics and airbox will be in the same spot if i install dt400 engine wiring loom will be the same just one less ground wire and red wire is not used dt175 is 7wire cdi and dt400 is 6 wire the red wire of the 175 is not used the wire ends may need to be changed to acomodate the wire keying i do also have to change the the rear sprocket Link to comment Share on other sites More sharing options...
nayruf Posted December 15, 2011 Share Posted December 15, 2011 All valid points, the brakes, the fitting of a physically bigger engine, the bigger carb etc...no room to connect to the airbox, making a new exhaust..blah blah! just not worth the headache Hi I agree, If better performance is what needed, I have often pondered about getting a spare barrel and boring my 175 to 200 cc, I have heard that has been done on TY 175's, have you thought about this option, My 175 will just touch 70 on the speedo with a nice cruise of 50 to 55 mph, if it were 200 cc iI figure it might just up this by 5mph and allow me to use 70 mph dual carriageways, all be it at 60 to 65 mph Link to comment Share on other sites More sharing options...
blackhat250 Posted December 15, 2011 Share Posted December 15, 2011 i do also have to change the the rear sprocket The line up of sprockets [ chain] could be a problem,, ,, & the 250 cylnder is 64 mm stroke... the DT400 is 70mm. port timing would not work Link to comment Share on other sites More sharing options...
Paulwhite Posted December 15, 2011 Share Posted December 15, 2011 Hi I agree, If better performance is what needed, I have often pondered about getting a spare barrel and boring my 175 to 200 cc, I have heard that has been done on TY 175's, have you thought about this option, My 175 will just touch 70 on the speedo with a nice cruise of 50 to 55 mph, if it were 200 cc iI figure it might just up this by 5mph and allow me to use 70 mph dual carriageways, all be it at 60 to 65 mph save ur money and just get a bigger engine/ bike........my xvs 125 bobber with a cbr 125 engine can reach 75mph. your best bet would be to try either a bigger sprocket on the front or a smaller one on the back to get more top end speed. works out about 300 quid cheeper Link to comment Share on other sites More sharing options...
shntat Posted December 16, 2011 Author Share Posted December 16, 2011 oh by the way anyone have a dt175e wire diagram? Link to comment Share on other sites More sharing options...
blackhat250 Posted December 16, 2011 Share Posted December 16, 2011 here you go,,, http://www.cmsnl.com/yamaha-dt175e-1978_model8652/partslist/ Link to comment Share on other sites More sharing options...
shntat Posted December 16, 2011 Author Share Posted December 16, 2011 here you go,,, http://www.cmsnl.com...8652/partslist/ this website has only parts fisch nothing with a wiring diagram like in the clymer manual Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 16, 2011 Moderator Share Posted December 16, 2011 pretty sure I have one Link to comment Share on other sites More sharing options...
shntat Posted December 17, 2011 Author Share Posted December 17, 2011 pretty sure I have one 1978 dt175 service manual with wire diagram? Link to comment Share on other sites More sharing options...
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