95-96 yzf stock air/fuel screw settings? turnout how much?

[matador0310]

hey, I took apart the carbs, and I was looking at the tutorial for it, it stops at hte air fuel mixture screws. I need to know what the stock settings are for them so i can turn them in and outy to make sure there set proper as that may very well be the reason my bike is running funny at idle. Any help would be apprieciated, and i didnt see it in the manual so i assume your not even supposed to touch them, but they were already drilled so im going on the afct that this will slove and is the problem with my idleing being all screwy.

[noshoes]

2 1/2 turns out from a light seat.....What is this "funny" idle you speak of?

[matador0310]

well the bike wont stay at an idle of 1300 rpms...i have to choke it and crank the idle up to 3000,, after 15 minutes of running, it starts randomly jumping to like 4000-5000 range for 15 seconds and then comes back down, i thourouly cleaned the carbs and am going to reconnect them right now and see what it does now. Ill let you know wat happens after this carb cleaning......tbc

[matador0310]

K. i checked the air/fuel scres, i hear everyone saying 2 1/2 turns out from all the way in is where you want them heres where mine was out, cylider 1 (left to right) was at 9 oclock, turned in to 6 of same hour, which means it was 5/8 turn out from fully in,,,,way off!
Cylinder2 - was at 9 pm, turned in to 4 p of same hour, so it to was 5/8 out from fully in.

cylinder 3- was turned in completely!!!! Wow no wonder prolly my bike was running like shit huh...
Cylinder 4 was 2 1/2 turns out from fully in.

My question i guess is ...do all the cylinders be the same turn out at 2 1/2 or do the middle go a little different? Iver heard that throw around a little bit and id like to know what you do for the stock bike? Thanks for any help everyone.

[haunter]

K. i checked the air/fuel scres, i hear everyone saying 2 1/2 turns out from all the way in is where you want them heres where mine was out, cylider 1 (left to right) was at 9 oclock, turned in to 6 of same hour, which means it was 5/8 turn out from fully in,,,,way off!
Cylinder2 - was at 9 pm, turned in to 4 p of same hour, so it to was 5/8 out from fully in.

cylinder 3- was turned in completely!!!! Wow no wonder prolly my bike was running like shit huh...
Cylinder 4 was 2 1/2 turns out from fully in.

My question i guess is ...do all the cylinders be the same turn out at 2 1/2 or do the middle go a little different? Iver heard that throw around a little bit and id like to know what you do for the stock bike? Thanks for any help everyone.

AFAIK all should be set to teh same turns out....but none of them will be in the same 'position' according to the head when they are turned out

[dragracer1951]

I have told a number of folks on this forum that the number is 2 1/2 turns out. That is the number that works for MY bike. The actual number will vary from bike to bike but that is a basic starting point. I bench cync the carbs, adjust the valves, warm the bike and sync the carbs with a vacuum gage. Then I set the idle at the lowest it will run at and starting with #1, turn the air screw in or out to get the highst idle. Turn the idle screw back down till it is at the lowest idle it will run at and do the same for #2 and so on. That will net a VERY close approximation of the "Proper" pilot air screw setting. That will also net you a nice running FZR.
Don't forget or neglect to set the valves first. This is important.

[matador0310]

I wish I could understand what all that meant really it sounds helpful...what is bench syncing the carbs? Right now my carbs are 2 turns out from benig tighted all the way.. and its not running right, I did clean them out thoroughly, but i didnt sync them, im trying to find a cheap enough car sync tool that works properly with meteres or guages. So I was thinking about it, and if I set the idle at the LOWEST it will run at, that would be like 1800-2500 rpms right now id say, if i started at #1 carb and turned the air screw to get a highest idle, when i get to carb #2 the idle knob will be already almost bottomed out wont it? if it made it through 2, if im only backing the screw out how will it now bottom out all the way and become ineffective? Or am I miss reading into it? I guess Ill try it and see what happens, but if you synce the carbs with a vacumm sync i would tend to think that it wouldnt need to be done as everyone has saidonce its carbs are cleaned, and synced usually there good to go.....im going to try it friday anyways i gues...if possible could you go a littel more into detail for a me so I dont screw it up,,,maybe explination if it all as well..if yo uhave time

[FZRDude]

When you cleaned the carbs, how did you do it? Did you disassemble each carb? Replace any o-rings? Get each carb reassembled correctly?

[matador0310]

I dissasemmbled each carb keeping parts seperated..cleaned all the parts other then the rubber ones, which I usedonly warm water to clean...after stirpped I cleaned all the carb body with carb cleaner,,went through a can of it blowing threw every carb....the assembly was simple...the only problem I had was the rubber where the big spring was in each carb,,,that was hell to get back in properlly and the spring as well, at first the springwas bending but I figured out a way to get the spring to stay on one part fully squished down and get the rubber sealer in the grooves and colse it up and it was fine.....three seem to have come out perfect, 1 was taking forever and I think its fine.....but they dont all make that perfect suction oice they did before that I remember.....

[dragracer1951]

The order in which you MUST do this is:
Adjust the valves while cold so that all valve clearances are within spec. This is critical as it will effect manifold vacuum and thus idle.
Then thouroughly clean the carbs and acertain that they are properly assembled. Do not proceed untill the carbs are PROPERLY assembled. This is critical.
Then bench sync the carbs with a drill rod or something of that nature. About 1/16th dia is about what you want. The actual diameter of the rod is not important but you adjust them so the rod just falls out of the butterfly.
Then screw in all pilot air screws untill they just LIGHTLY bottom. Do not overtighten!!!
Turn the screws out 2 1/2 turns on all of the pilot air screws. This will be a good starting point.
Warm the bike. Adjust the idle to the lowest speed that it will run at. This must be below 1000 rpm. All of the bikes I have done this to I could get the idle down to about 400 or 500 rpm. Lower is better.
Adjust the #1 pilot air screw in or out till the highest idle is achieved. Do this slowly and listen carefully for any speed changes. Make small changes to the screw, don't just turn it a half turn at a time and expect dramatic change, this is a VERY subtle adjustment!!! Lower the idle adjuster back to where it idles at the lowest that it will run at. Do the same for #'s 2,3, and 4
This will be VERY close to the proper pilot air screw setting as it came from the factory.
It is absolutely critical that these tasks be performed in the order I have set them out in. It is absolutely critical to not go on to the next step before the previous step is completed properly.
These are complex motors. There is a lot of cam overlap and thus there is not a lot of manifold vacuum to operate the slides. The slides are actuated by manifold vacuum and that is applied to the slides by opening the butterflies. The slide has NO connection to the throttle. None. Zero, Zip, Nada. You can not judge slide position by throttle position.
Now go have at it.

[matador0310]

Ok..i get it sorta heres my concerns and questions on this great naser so i can do this tomamrrow ....
How do I bench synce the carbs like you say before putting them back in? please explain in retard terms so i dont need to ask again , i have no idea what rod you were talking about at 1/16...thanks

Questions 2 is this: after the bench sync you were talking about adjusting the idle screws to 2 1/2 out for each right...then warming the bike, and then setting the IDLE to the lowest it will go and stil keep the bike running...ususally right now my bike is dying before this point could get below 200 rpms..but lets say warm it does get down around 500 rpms for ha has sake right...now if I do what you said and adjust the 1st cylider to its highest idle point, and then bring the idle knob down to the lowest point it will still run the bike, having the idle screw already low from initially being at 500 rpms, it wont back out any lower at it was at 500, then it was untouched as i was only using the 1 cylinder screw to go higher, when i go back to the idle screw it wont have anywhere to go further down will it>? If its like 1/2 turn from being fully out at 500 rpms and i go to back it out more to bring it down from the highest idle from 1st cylinder there wont be any more for it to turn out will there? Am i making this a clear question cause it seems confusing to write but easy to think about in my head lol anyways if you get my question could you explain it better for me please as i wanna do this tommarrow...>? Thanks

[dragracer1951]

Ok....
The rod you use ia a 1/16th " drill. You want to use the shank portion not the drill portion....If you set the butterflys so it JUST falls out with the sync screws, then you will have all of the butterflys roughly at the same opening. This is rough sync'd. Now...adjust the sync on the bike with a vacuum gage. Now the carbs are closely synced. Warm the bike to do this.
Now....you should have an idle that you can lower to 4 or 5 hundred revs and still have room on the adjuster to lower it. You "Should" be able to have the bike die by lowering the idle adjuster knob.
Then do the pilot air screws as sugested

[matador0310]

ok...ill try this on this weekend and see what ive got...ill keep you informed on how itturns out friday for me....I just dont think my bike will run that low of rpms ever until its synced, so its gonna be hard to sync it if it cant do it...lol anyways ill ltry and see what i can do

[dragracer1951]

Read my post again.....
Adjust the valves first.
Bench sync the carbs after you have cleaned the snot out of them. Three times. Completely taken apart. One at a time.
Sync them with a vacuum gage and THEN do the pilot air screws.
Do it in order.