muppet Posted April 21, 2011 Posted April 21, 2011 Ok, i'm a fairly happy bunny in that i have the bike MOT'd, insured and taxed and its goes but ....... its now driving me mad. It keeps cutting out at junctions which is embarassing me now and knocking my confidence. Ive adjusted the throttle stop screw and i can get the bike to idle at 1500-2000 revs but then when you pull the throttle its stutters and dies. I then adjust it to 2000-3000 revs and its fine so i take it out for a blast round the roads and its cuts out when you come to pull away from a junction. It mainly happens or 99.9% happens when the choke is off even when the engine is warm. I havent adjusted the pilot screw as I would rather ask before adjusting something I dont fully understand and i could create more problems by adjusting it. Apart from that I DO LOVE IT and ive had 1 offer to buy it on my first ride out - NOT A CHANCE its MINE!
Moderator Airhead Posted April 21, 2011 Moderator Posted April 21, 2011 Hi muppet, I would guess the pilot screw should be around 1.5 turns out from gently closed (all the way in), failing that I would be having a look at clearing the pilot jet. Hey I was kinda hoping to see some pics now you have finished it
muppet Posted April 21, 2011 Author Posted April 21, 2011 cheers - ill have a look tomorow as its 10.30pm. Dont think the neighbours would like me much if i started the bike up! I'll take some proper pics tomorow and post them on photobucket.
muppet Posted April 22, 2011 Author Posted April 22, 2011 ok, i adjusted the screw 1.5 turns and no difference. stripped the carb out and cleaned with contact cleaner and compressed air. Got the bike to idle at 2000 revs without cutting out, took the bike out and it ran better but the engine still stays to high at idle. Adjusted and adjusted some more and gave up at 1pm. Now its not the original carb that came with the bike cause i errrr damaged it so i got a replacement off fleebay which was very very very near identical. How do i know what type of mikuni I have on now? The needle is on ring 2(middle position), cleaned the float bowl, jetting needle etc (got the yamaha workshop manual) I can only think its the set up that causing this problem but its killing me with this hot weather and not being able to use properly oh and the fact everytime im done off come the handlebars and put inside the house for security. right, now to relax and watch quadrophenia on dvd.
Moderator Airhead Posted April 22, 2011 Moderator Posted April 22, 2011 ok, i adjusted the screw 1.5 turns and no difference. stripped the carb out and cleaned with contact cleaner and compressed air. Got the bike to idle at 2000 revs without cutting out, took the bike out and it ran better but the engine still stays to high at idle. Adjusted and adjusted some more and gave up at 1pm. Now its not the original carb that came with the bike cause i errrr damaged it so i got a replacement off fleebay which was very very very near identical. How do i know what type of mikuni I have on now? The needle is on ring 2(middle position), cleaned the float bowl, jetting needle etc (got the yamaha workshop manual) I can only think its the set up that causing this problem but its killing me with this hot weather and not being able to use properly oh and the fact everytime im done off come the handlebars and put inside the house for security. right, now to relax and watch quadrophenia on dvd. what is the year and model of your bike?... you havent filled in any of your profile and I cant remember What are the id letters-numbers on the original carb body...what are the id letters-numbers on the replacement?
muppet Posted April 22, 2011 Author Posted April 22, 2011 Just updated the details. Its a 1991 (H reg) but a 1990 model. 3md model (frame and engine number). Where is the id number for the carb then cause all i see is mikuni?
Moderator Airhead Posted April 22, 2011 Moderator Posted April 22, 2011 Just updated the details. Its a 1991 (H reg) but a 1990 model. 3md model (frame and engine number). Where is the id number for the carb then cause all i see is mikuni? Can you see anything like this, this is a DT175MX carb, I take it yours is similar but possibly has water pipes also?
muppet Posted April 23, 2011 Author Posted April 23, 2011 I cant find any markings on the carb except the manufacturer. I've got a week to get it running as its booked in for the local yam dealers because ive had enough of it. I'll play about with it some more but i doubt i'll get it working correctly in that time. I'll keep you posted but any more help and i'll try that before it goes in. cheers
Moderator Airhead Posted April 23, 2011 Moderator Posted April 23, 2011 I cant find any markings on the carb except the manufacturer. I've got a week to get it running as its booked in for the local yam dealers because ive had enough of it. I'll play about with it some more but i doubt i'll get it working correctly in that time. I'll keep you posted but any more help and i'll try that before it goes in. cheers OK then did you compare everything between the two carbs at the point of swapping them, ie Jet needle Needle jet Clip position Main jet Pilot jet Throttle valve cutaway number ????? According to Haynes manual 1991 is a 3RN4 Dates of import Jan 91 to Feb 93 Frame / Eng no 3MD-000101 Main Jet 210 Air jet 0.7 Jet needle 5J25 Clip 4th from top Needle jet Q-2 Throttle valve cutaway 2.5 Pilot jet 22.5 Power jet 60 Air screw turns out 1 1/2 Float height 21mm
muppet Posted April 23, 2011 Author Posted April 23, 2011 Ok, i think you may have solved some of the mystery here on what carb i have. Thanks to you I came across the 1999 model onwards in the haynes manual and im pretty certain thats what i have. It looks identical as with p141 pic 6.1 plastic insert across main and pilot jets as i definetly have that on my carb, pic 6.2 spring seat (luminous green) again on mine. When i brought the carb off fleebay it didnt list the year (came off a field bike) but it looked the same. On p85 pic 3.4 i am thinking thats what mine should be but im now convinced its 99 onwards. Which now leads me to the next question will this carb work ok on my bike if its set up ok. I'll take the carb off on tuesday when im back and take some pics of the float bowl removed so you can see. cheers
Moderator Airhead Posted April 23, 2011 Moderator Posted April 23, 2011 Ok, i think you may have solved some of the mystery here on what carb i have. Thanks to you I came across the 1999 model onwards in the haynes manual and im pretty certain thats what i have. It looks identical as with p141 pic 6.1 plastic insert across main and pilot jets as i definetly have that on my carb, pic 6.2 spring seat (luminous green) again on mine. When i brought the carb off fleebay it didnt list the year (came off a field bike) but it looked the same. On p85 pic 3.4 i am thinking thats what mine should be but im now convinced its 99 onwards. Which now leads me to the next question will this carb work ok on my bike if its set up ok. I'll take the carb off on tuesday when im back and take some pics of the float bowl removed so you can see. cheers First things first I cant reference your pictures or info with regard to page numbers, obviously we have different manuals mine is ISBN 978 1 84425 626 6 The later models had a completely different carb (mine has one) a flat slide TM type rather than the round slide predecessor, you must have noticed they looked completely different? yet you say it was near identical...thats confusing, I wonder if someone before you changed the carb also. Can you post pics of them both?
muppet Posted April 26, 2011 Author Posted April 26, 2011 Got the old carb back today, and the only marking i can find on that are 3m?00 t052. Havent had time to strip the carb off the bike yet to fully check it. Pics uploaded on bucket of old carb.
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