Moderator Airhead Posted October 21, 2011 Moderator Share Posted October 21, 2011 blocked exhaust silencer? Try the vacuum cleaner test on it or clean up the small tube end and try blowing down it...should be no back pressure Link to comment Share on other sites More sharing options...
clivew1965 Posted October 21, 2011 Author Share Posted October 21, 2011 hey you may be right, perhaps thats why he changed the exaust. will have a look in the morning ) Link to comment Share on other sites More sharing options...
clivew1965 Posted October 21, 2011 Author Share Posted October 21, 2011 I can blow through it but you dont get a massive blow through. Have put some tiolet cleaner in it and will power wash it through in the morning. Will also put original carb back on tomos. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 21, 2011 Moderator Share Posted October 21, 2011 I can blow through it but you dont get a massive blow through. Have put some tiolet cleaner in it and will power wash it through in the morning. Will also put original carb back on tomos. well the toilet cleaner may have some effect by virtue of the detergent in it, however if anything that stuff may be mildly acidic to clear limescale from hard water areas caustic is a better thing to clear carbon build up...I would think a better solution (literally) would be a caustic based solution such as sink unblocker, get yourself round to aldi for a couple of bottles of 'Buster bathroom plughole unblocker' bung up the small end and fill it up with this stuff overnight, top up with hot water as necessary...follow this with the power washer and it should shift loads of crap. Link to comment Share on other sites More sharing options...
clivew1965 Posted October 23, 2011 Author Share Posted October 23, 2011 cheers oldgit, ;o). Doing what you said. Have taken a loan out now so may keep it. But also managed to pick up a dt250 so will have something to mess with. Can you tell me standard settings for the carb dt250 mx 1978. Runs ok but feels like its missing around 3000 to 4500 revs. Hit it all the bloody time. Link to comment Share on other sites More sharing options...
clivew1965 Posted October 25, 2011 Author Share Posted October 25, 2011 DT175mx runs much better now ), very crisp but i am struggling to get it to idle? air screw set 1 1/2 to 1 3/4. It either dies or its above 2000rpm. adjusting the idle screw Still need advice on the 250mx. Feels like its missing heavily around 3 to 5 thous. Not very crisp either. bit sluggish. Any advice would be great. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 25, 2011 Moderator Share Posted October 25, 2011 DT175mx runs much better now ), very crisp but i am struggling to get it to idle? air screw set 1 1/2 to 1 3/4. It either dies or its above 2000rpm. adjusting the idle screw Could still be carb issues Clive, with a 2.5 slide cutaway it may well be very lean, theres more to it than just the 160 main jet, keep an eye on ebay you will find a carb before too long, when you do ask the seller if it is id 3U500, thats the one you want. Link to comment Share on other sites More sharing options...
clivew1965 Posted October 26, 2011 Author Share Posted October 26, 2011 Could still be carb issues Clive, with a 2.5 slide cutaway it may well be very lean, theres more to it than just the 160 main jet, keep an eye on ebay you will find a carb before too long, when you do ask the seller if it is id 3U500, thats the one you want. 160 main jet, its a 130 standard on the 175 ) Thats the carb now fitted m8. with new internals Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 26, 2011 Moderator Share Posted October 26, 2011 160 main jet, its a 130 standard on the 175 ) Thats the carb now fitted m8. with new internals we seem to be going round in circles here? early bike 130, late bike 160 i'm sure you have seen me say this in other posts? not just that though there are all knids of other differences, with the exception of the pilot jet the later carb is richer on all fronts, if your bike has a later airbox then a 3u500 carb should be fitted ok then for the earlier version Mikuni VM24SS, Number 2H500 Standard Set up with factory porting, standard exhaust and air filter Throttle Slide cutaway, 2.0 Needle, 4j13 Clip position 3 from top Needle Jet, 249 0-2 Main Jet, 130 Pilot Jet, 25 Reed side diameter, 35mm Filter side diameter, 43mm Length, 85mm Float Height, 21mm Later version for bike with airbox on left Mikuni VM24SS, Number 3U500 Standard Set up with factory porting, standard exhaust and air filter Throttle Slide cutaway 1.5 Needle, 4j6 Clip position 3 from top Needle Jet, 267 0-8 Main Jet, 160 Pilot Jet, 20 Reed side diameter, 35mm Filter side diameter, 43mm Length, 85mm Float Height, 21mm so you see for example that your 125 carb with its 2.5 slide cutaway is leaner than the early 175 with its 2.0 cutaway, and even further away (leaner still) that the 1.5 cutaway of the later model 175 carb perhaps this is why you have idle issues and also its risky for overheating and seizure if you run too lean as well you know! Link to comment Share on other sites More sharing options...
clivew1965 Posted October 26, 2011 Author Share Posted October 26, 2011 Mines the first version m8 Mikuni VM24SS, Number 2H500 Standard Set up with factory porting, standard exhaust and air filter Throttle Slide cutaway, 2.0 Needle, 4j13 Clip position 3 from top Needle Jet, 249 0-2 Main Jet, 130 Pilot Jet, 25 Reed side diameter, 35mm Filter side diameter, 43mm Length, 85mm Float Height, 21mm Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 26, 2011 Moderator Share Posted October 26, 2011 yeah sorry clive i'm getting mixed up with another poster, too much going on at the moment m8 Link to comment Share on other sites More sharing options...
clivew1965 Posted October 26, 2011 Author Share Posted October 26, 2011 Well i can only look for air leaks. Not sure what else it can be. I take it ylu judt let the needle slide cut away bit hit the bottom and then ajust throttle bable to suit. Then idle screw? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 27, 2011 Moderator Share Posted October 27, 2011 sounds good, and have a spray around the inlet and left crank seal with WD40 Link to comment Share on other sites More sharing options...
clivew1965 Posted October 27, 2011 Author Share Posted October 27, 2011 sounds good, and have a spray around the inlet and left crank seal with WD40 Its had new bearing and seals but will re check. cant look until tomos Link to comment Share on other sites More sharing options...
Recommended Posts