Moderator DirtyDT Posted May 16, 2009 Moderator Share Posted May 16, 2009 Hi All, I have been stripping more off the bike today and am going to refurb the carb. Searching through earlier threads I understand that the carb on these is a VM24ss. Are there any refurb kits available for this? There are some specs in earlier threads re the jets, float height and needle position but could someone please confirm what the UK specs are for this year. I have not got as far as taking the carb apart yet as the needle is bent. I can't read the writing on it as it is worn but it looks like mj6. The circlip is in the 4th notch from the bottom. I obviously need one of these. Any advise on where I can order the parts for this. I have looked at cmsnl but am not sure which model I should be looking at and if the European specs are the same. Cheers Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 16, 2009 Moderator Share Posted May 16, 2009 Try siriusconinc thats where I got mine from. Link to comment Share on other sites More sharing options...
JimR Posted May 16, 2009 Share Posted May 16, 2009 Hi All, I have been stripping more off the bike today and am going to refurb the carb. Searching through earlier threads I understand that the carb on these is a VM24ss. Are there any refurb kits available for this? There are some specs in earlier threads re the jets, float height and needle position but could someone please confirm what the UK specs are for this year. I have not got as far as taking the carb apart yet as the needle is bent. I can't read the writing on it as it is worn but it looks like mj6. The circlip is in the 4th notch from the bottom. I obviously need one of these. Any advise on where I can order the parts for this. I have looked at cmsnl but am not sure which model I should be looking at and if the European specs are the same. Cheers Hi, 1981 was an odd time for bikes above 125cc and less than 350cc as the 125cc limit was looming up and the government add a 10% tax to imported vehicles (to safe guard BL .. & look what happend !) So some bikes registered in 1981 may be 1980 models (they weren't selling too well) registered before the 1 Mar 1981 in order to avoid the 10% tax. I guess there is little difference between the two but I would guess your bike is an 1980. by late 1983 Yamaha had loads of 1981 DT175's in stock and were offered to the trade as 'buy on get one free' as long as you bought an XJ750 in the same order these bikes were 1981 manufacture ! Regards Jim Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 16, 2009 Author Moderator Share Posted May 16, 2009 Thanks OG. I did not know that JimR. Mine is registered in March 81 but not the first. I do remember the times when the law changed. I had a Suzuki250 GT on L plates around then. NRP seem to be the supplier of Keyster in the UK but there site is not too good. I have emailed them but if not I guess that I will have to buy from abroad. Cheers Link to comment Share on other sites More sharing options...
JimR Posted May 16, 2009 Share Posted May 16, 2009 Thanks OG. I did not know that JimR. Mine is registered in March 81 but not the first. I do remember the times when the law changed. I had a Suzuki250 GT on L plates around then. NRP seem to be the supplier of Keyster in the UK but there site is not too good. I have emailed them but if not I guess that I will have to buy from abroad. Cheers What I was getting at is the bike maybe a 1980 model registered later so check that the 1980 & 1981 specs are close (I cannot remember too long ago !) .... thinking about it ... it way have been the end of March ... I'll research it and get back to you Regards Jim Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 16, 2009 Author Moderator Share Posted May 16, 2009 What I was getting at is the bike maybe a 1980 model registered later so check that the 1980 & 1981 specs are close (I cannot remember too long ago !) .... thinking about it ... it way have been the end of March ... I'll research it and get back to you Regards Jim It does seem so. the benefit of the buy one get one free is there are still plenty about. I emailed siriusconinc and they came straight back $19 plus $7.5 for postage. That is about £17.50 still a bargain but damn the weak pound Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 16, 2009 Moderator Share Posted May 16, 2009 It does seem so. the benefit of the buy one get one free is there are still plenty about. I emailed siriusconinc and they came straight back $19 plus $7.5 for postage. That is about £17.50 still a bargain but damn the weak pound If you get one from siriusconinc and its a DT175E one, there will be some difference, ie the main jet will be 140, the american bikes had a different carb for some reason, I cant remember which one I bought now, ask if they have DT175MX...It will have a 130 Jet., do you know the carb specs? Link to comment Share on other sites More sharing options...
Moderator Cynic Posted May 16, 2009 Moderator Share Posted May 16, 2009 Ok mate, there is only one spec for the 4J4 modle and the 2K4 and the 2X2 shared the same settings. DT175 (2X2/2K4) DT175 (4J4) Manufacturer Mikuni Type VM24SS IDno 2h500 3U500 Main Jet 130 160 Main air jet 0.5 Jet needle 4J13 4J6 Clip position (groves fr top) 3rd Needle jet 0-4 0-8 Throttle slide cutaway 2.0 1.5 Pilot jet 25 20 Pilot air screw (turns out) 1.5 Float valve seat 2.5 Starter jet 20 Float height 21mm+/-1.5mm (0.83+/-0.04 in) Idle speed (rpm) 1300-1400 1500+/- 50 Where the gaps are on the 4J4 the earlier model carries over. The VM24ss seems to be a carb that Yamaha used extensively through the life of its 125/175 trail bikes so you really need to be sure of which one you have before you get carried away with overhall kits. The manual i'm looking at at the moment has 15 different specs listed for the VM24SS, if you include the VM20 and VM22 which look identical thats over 20 possible variations. You need to be sure of what you have thats why i have listed the 2 most likely combinations. But you cannot discount someone fitting a carb from a different bike as a quick fix. Imagine you have a carb on your bike from a 2X2 for example (which will work fine pretty much) and you then think the jettings all wrong and fit the 160. You see my point. Hope this helps. Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 16, 2009 Author Moderator Share Posted May 16, 2009 Cheers OG & Cynic, It is a 4J4. The ID No is 3U500. What I thought said MJ6 on the Jet needle is 4J6 The Siriusconinc site is down at the moment but they did not have a huge selection. 4 types and one of those was sold out so I could not see the specs. I think cms have some individual parts but not the Jet needle. I found one here Here Addition If C$ then about £4.50 plus postage I would still prefer a set though Link to comment Share on other sites More sharing options...
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