dt175david Posted November 12, 2009 Share Posted November 12, 2009 Hello all, I am new to this forum and the info on hear has been great but now i have my own problem i have been cleaning up my old 1988 dt175 the starter coil was shot so i got one off ebay and installed it the bike ran great only one problem the thing ran backward when i put it in gear it went in reverse i worked out my timing was out by 180 and the coils where from an other model so i swapped the coils to my old backing plate and the lighting and starter coils where in opposite spots but the pulse coil was in the same spot i put it all back and the thing will not start it has still got spark and the plug is wet have i done damage running backward or i have just not got the timing right if it is timing then what is the proper way to set it. thanks all any help would be great... Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 12, 2009 Moderator Share Posted November 12, 2009 1988? got a picture? what is the engine number? dont think they were around in the uk then but still exporting a similar bike elsewhere Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 12, 2009 Moderator Share Posted November 12, 2009 Hello all, I am new to this forum and the info on hear has been great but now i have my own problem i have been cleaning up my old 1988 dt175 the starter coil was shot so i got one off ebay and installed it the bike ran great only one problem the thing ran backward when i put it in gear it went in reverse i worked out my timing was out by 180 and the coils where from an other model so i swapped the coils to my old backing plate and the lighting and starter coils where in opposite spots but the pulse coil was in the same spot i put it all back and the thing will not start it has still got spark and the plug is wet have i done damage running backward or i have just not got the timing right if it is timing then what is the proper way to set it. thanks all any help would be great... You cannot get the timing out by 180 degrees on a stroker, that would be at the bottom of the piston stroke. Your engine's timing can be varied by about 10 degrees, max And no if you have actually managed to get it running backwards it won't actually do it any harm, aside from the fact that the kicker would have jammed or the transmission if you were bumping it. Link to comment Share on other sites More sharing options...
dt175david Posted November 13, 2009 Author Share Posted November 13, 2009 OK i have got it running in the rite direction now the pick up coils where different but only with the way the wires came out of the coil itself on the new one i got the earth wire came out the top and the power wire came out the bottom but the one i had the wires where opposite what the prob i have now is that when it is hot i can only rev it quick once after a start if i try to rev it quick after that is goes to die when i get off the throttle it returns to norm idle and when i ride it is very sergie it takes off then slows down and then takes off a bit more what could this be??? also thanks for the quick replys guys been a good help, i will post some pics in the bar when she is up and running good Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 13, 2009 Moderator Share Posted November 13, 2009 OK i have got it running in the rite direction now the pick up coils where different but only with the way the wires came out of the coil itself on the new one i got the earth wire came out the top and the power wire came out the bottom but the one i had the wires where opposite what the prob i have now is that when it is hot i can only rev it quick once after a start if i try to rev it quick after that is goes to die when i get off the throttle it returns to norm idle and when i ride it is very sergie it takes off then slows down and then takes off a bit more what could this be??? also thanks for the quick replys guys been a good help, i will post some pics in the bar when she is up and running good Float height is set wrong, or your fuel feed is blocked or restricted. Either way you are burning up the fuel in the carb then having to wait while it refills. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 13, 2009 Moderator Share Posted November 13, 2009 Float height is set wrong, or your fuel feed is blocked or restricted. Either way you are burning up the fuel in the carb then having to wait while it refills. Pull the fuel pipe from the carb spigot and check for a good flow of fuel in both the 'ON' and 'RES' positions, if flow is bad then there is a screen inside the fuel tap. Be careful because the hexagon on the fuel tap bowl is soft and will round off if you get heavy with it. I am assuming it is not a vacuum operated one but not sure because you stated the year as 1988? Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 13, 2009 Moderator Share Posted November 13, 2009 Pull the fuel pipe from the carb spigot and check for a good flow of fuel in both the 'ON' and 'RES' positions, if flow is bad then there is a scteen inside the fuel tap. Be careful because the hexagon on the fuel tap bown is soft and will round off if you get heavy with it. I am assuming it is not a vacuum operated one but not sure because you stated the year as 1988? He's one of the convicts OG, they obviously dont have the emmisions claptrap that we have to suffer down under. As a result they could and did keep the old DT175 motor(much stronger and more reliable than the LC) going right up to around 2006 (I think), so he basically has a DT LC with the LC bit missing Link to comment Share on other sites More sharing options...
dt175david Posted November 14, 2009 Author Share Posted November 14, 2009 the fuel tap has two tubes coming off it one fuel witch flows good and the other is vacuum the bike never had a fuel filter on it until i put one on in this fix-up so i will pull the carb off and give the jets a clean hope this works... should i check the fuel/air mix first ??? i will post some pics soon... also i seen some sparks from the mag so i rediped the coils and put new cables on but that did not fix the prob. could it be because i have the timeing off? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 14, 2009 Moderator Share Posted November 14, 2009 the fuel tap has two tubes coming off it one fuel witch flows good and the other is vacuum the bike never had a fuel filter on it until i put one on in this fix-up so i will pull the carb off and give the jets a clean hope this works... should i check the fuel/air mix first ??? i will post some pics soon... also i seen some sparks from the mag so i rediped the coils and put new cables on but that did not fix the prob. could it be because i have the timeing off? Yes sort the carb out good and proper and set the float height to 21mm. I expect you havent got a dial gauge and stand so wont be ablle to set your timing by the book....But if you get a Xenon strobe lamp you will be able to check it, just connect the strobe lamp to a 12v car battery and then to the bikes HT lead and away you go, there may be three inscribed lines in the mag rotor; you are looking to align the centre on with the mark on the crankcase, i'll try to find a picture. Link to comment Share on other sites More sharing options...
dt175david Posted November 14, 2009 Author Share Posted November 14, 2009 when i has it running backwards it was reving fine but i gess i bit of crap may of found its way in.. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 14, 2009 Moderator Share Posted November 14, 2009 when i has it running backwards it was reving fine but i gess i bit of crap may of found its way in.. But you really DO need to check the timing, when it ran backwards the timing would be retarded and yes it would rev freely Link to comment Share on other sites More sharing options...
dt175david Posted November 16, 2009 Author Share Posted November 16, 2009 got it to rev good when i was cleaning the carb i found that the circlip that holds the needle in was broken os got a new one and away it went will check the timeing with a timeing light next... Link to comment Share on other sites More sharing options...
dt175david Posted November 16, 2009 Author Share Posted November 16, 2009 also what do you think about running with out a muffler mine had a broken mount and my brother used a ark welder to try and fix and blew holes in it what i was going to do is make up a piece of pipe to exit the gasses away from my leg and go for it, i run with 4 strokes so noise is not really an issue.. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 16, 2009 Moderator Share Posted November 16, 2009 also what do you think about running with out a muffler mine had a broken mount and my brother used a ark welder to try and fix and blew holes in it what i was going to do is make up a piece of pipe to exit the gasses away from my leg and go for it, i run with 4 strokes so noise is not really an issue.. If you mean running without a muffler meaning the tailpipe at the back then that doesent make all that much difference, run without an expansion chamber the engine wont last 10 minutes before it destroys itsself. Link to comment Share on other sites More sharing options...
dt175david Posted November 17, 2009 Author Share Posted November 17, 2009 yes the tail pipe/muffler i am going to make my own just to exit the gasses out past my leg do you have any suggestions on the pipe , just a straight pipe , a pipe with holes at the end of the pipe ??? any ideas would help , all the info has been great thanks.. Link to comment Share on other sites More sharing options...
KirriePete Posted November 17, 2009 Share Posted November 17, 2009 2 stroke exhaust construction is a combination of fine art and brain-melting physics. Basically, they need a certain level of back pressure to assist in scavenging the gases from the combustion chamber and allowing the cleanest fresh charge of fuel/air for the next cycle. A straight pipe will make it run like a donkey and may well end up damaging the mill. Look up Walter Kaaden and MZ development - yes, he/they were waaaaay ahead of the game, so much so that Suzuki had to steal the designs to get their strokers running well. Click here for more info on 2-stroke exhausts than you ever thought you'd need. Then take apart the remains of the pipe you've got and have a look at how the curves and various holey pipes work..... Then go and spend money on a replacement. Link to comment Share on other sites More sharing options...
dt175david Posted November 18, 2009 Author Share Posted November 18, 2009 2 stroke exhaust construction is a combination of fine art and brain-melting physics. Basically, they need a certain level of back pressure to assist in scavenging the gases from the combustion chamber and allowing the cleanest fresh charge of fuel/air for the next cycle. A straight pipe will make it run like a donkey and may well end up damaging the mill. Look up Walter Kaaden and MZ development - yes, he/they were waaaaay ahead of the game, so much so that Suzuki had to steal the designs to get their strokers running well. Click here for more info on 2-stroke exhausts than you ever thought you'd need. Then take apart the remains of the pipe you've got and have a look at how the curves and various holey pipes work..... Then go and spend money on a replacement. i am keeping my old expansion chamber section all a want to do is extend the end so it exits in a better spot Link to comment Share on other sites More sharing options...
Moderator Cynic Posted November 19, 2009 Moderator Share Posted November 19, 2009 i am keeping my old expansion chamber section all a want to do is extend the end so it exits in a better spot Its not technically ideal, but it wont make all that much difference. Probably be a little down on pure performance and a good bit noisier but thats about it. The expansion pipe is the really critical part. Link to comment Share on other sites More sharing options...
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