rich running on front two cylinders

[yamahaha]

hello just wondering if anyone can tell me why the front two cylinders on my girlfriends nc 30 run way richer than the rear two also hers has 36 000k on the tacho i have it all in bits at the moment and am just about to take the rocker covers off to measure the shims i'm guessing the exhaust valves will be all tight any comments would be much appreciated

ian

[eamer1989]

main reason people use bigger jets in the front as the front cyclinders are cooled down more than the rears so lets you able to run bigger jet size in the front thats why its proberley rich as hasent been done properly

[yamahaha]

ah right gonna pull the carbs off tommorow just found a great guide to standard jet sizes and tuned much appreciated thanks for the reply

[Neosophist]

Yep.

Front / Rear jets and emulsion tubes are different.

it's not uncommon for somebody to strip the carbs and mix them up.

More holes in the rear with regards to emulsion tubes.

Cam (Dataracers) written a superb guide up on the forum :)

[yamahaha]

aye i got the carbs off tonight they have definately never been off ever before and what a bastard of a job my hands now have cramp off trying to get the front right inlet stub loosened managed to loosen the lower one on that carb and got a block of wood and prised off the little blighters
cause for the rich running on the front cylinders was the choke was siezed on just the front two
newe problem is the carbs look slightly twisted eg out of square with each other is this normal

[eamer1989]

there are 2 pinch bolts on the side on the carbs do you have a haynes manuel if not i have one somewhere which i will sell ya, basicly undone them slightly and twist carbs back to looking straight and choke stuck thats new but yea well done its getting them back on trust me lol

[yamahaha]

just fucking realised i didnt need to take ally top plate off the carbs this would of held them square but on doing that i noticed there are two pipes connected to the air box and the tops of the carbs ?????????????/? idont know what they do but go into the tops of both pairs of carbs an have perished what a horible bike to work on i used to work on buells and they were easy gonna burnn it grrrrrr .....................any ideas what these pipes do????????????????

[eamer1989]

if its the ones im thinking of there breathers hope this helps, i have a set of carbs for sale also if thats any more help lol, should be an easy fix if the rubbers just split and yea that was silly taking the top plate off :D

and buells are so much more rubbish with there imperial allen keys D:

[Neosophist]

Yep you should leave the top plate on, you can get some leverage with a block of wood quite easily if its still on.... Ah well, least there off :-)

[yamahaha]

fitted top plate back on hmm that was fun ha ha haha i noticed there was a little bracket holding the two pairs of carbs together took that off went together easy why anyone would want to fix these bikes is beyond me unless you had ridden one first took one float bowl off never ever been off still as it left the factory no muck in any of the carbs just need bigger jets for two of them and washers who would you reccomend (loud exhaust)