ive just about had it with this stupid thing... desperately need help

88 yamaha 570

88 yamaha 570

New member
Joined
Jan 3, 2010
Messages
343
Age
33
Location
Bridgeport, NY
ok guys i think its done for this sled, im about to try and cross open water and dump it. i have been trying to get things going good with this thing and today was trying to adjust the air/fuel mixture screw and i set it at 5/8s out, 1 turn out, 1 1/4, and so on, i think im at like 2 right now and i still cant get it to run right it seems like its running too much gas, it seems perfect at about 20mph till 50, then when it hits 50 it just drops rpms and runs like crap, and its also no good in bottom end as well, i need someone close to Bridgeport, NY who might have a flow meeter or might be able to help me to get this to run cheaply, i have no money at the moment, and need help were having a poker run on Saturday and id like to show up to it...
 
Don't know what you have done to it previously. Have you taken the carbs and cleaned? Chokes sticking? I have an 89 and it is finicky as hell. If your needle and seat is dirty could be flooding?
 
Have you checked out the tech section How to clean carbs ?I have had problems with my 90 exciter with the choke sticking do to water getting into the cables from the switch on the dash.

Remove both choke holders on the carbs and lube up the cables so they work freely.

If they stick ay all it will do what you are saying.
 
First thing you need to do is get your self a service manual,it'll have all the specs and adjustments there for you,them round side carbs can be tricky and a book will have pics and procedures showing you how to do it vs. us telling you without pics.

check ebay..
 
well first of all theo, and blue, i removed the chokes, one cable was sticking and the other wasn't, switched to a primer and plugged the choke ports, and have also pulled the carbs off and had all needles and everything cleaned out on them, maybe it still needs to be cleaned more but im not sure, and daman, im glad you posted on here ive heard your a legend to TY, but i do not have 30 dollars to spend on a service manual, i actually ran out of gas about a mile from home testing and tuning, i might pull carbs apart and reset them to stock specs and check the forum for proper cleaning procedures. my sled was supposed to be bored, clutched and piped, its got an aftermarket pipe on it but is stock bore when i rebuilt it, and i don't think its clutched its all stock but im going to look into cleaning the carbs again.
 
Well if you actually ran out of gas, then maybe you were sucking air and that is the reson it was running bad.
 
no its been like this for a while, no top end, when i put full throttle it just bogs out, is there a screw inside the carb that needs to be set a certain way? or are they all snug inside?
 
you said your sled has a pipe...... where was it ridden before you baught it???

If the weather is much different than it is near you say altitude or average temp you might have a jetting issue!!!

what pipe do you have???

what jets are in the carb???

call the pipe manufacturer and find out what jets you should be running....

if you cant get the carbs adjusted, you know the choke isnt sticking, and youve cleaned them properly....... Jets are next in line for me......
 
dont let the little things pass. i had a old excel 540 do the same thing and it was the kill switch,the switch would half assed ground it self out at higher rpm i by bassed the switch to find out then bought a new one and its worked fine ever sence
 
i don't know how to find out what kind of pipe it has, my friend is the previous owner and ran it a mil away from me on same trails and he said it ran fine, but he also didn't go very fast either, the guy who had it before him i have no clue where he ran it, and how do i tell what jets i have?
 
Manuals yamaha 570 can be had for cheap off ebay or post a wanted ad here, i cant stress enough how important one is to someone thats is under experienced with sleds or experienced because of the valuable information,and specs,try to find one.

first off adjusting screw ain't going to help with the issues your having,first thing you need to do is pull carbs tear them down and see whats going on in there, what kind of jetting you have in there,check float hight to spec,sync carbs,clean carbs,clean choke circuit,then after all is clean and set re install and take it for a rip and check jetting/plug color,etc,etc you gota start some where.

also a compression check should be done to make sure alls well there,they are good little sleds my BL had one and it ripped pretty good the round side carbs are a PITA tho not like the flat sides takes more of an effort to tune em in but can be done.

wish you were closer id lend you a hand,your issues sound simple just need to find it.

i may know where to get a manual i'll let you know
 
i cleaned them out about 3 weeks ago and i dont have tools to check float height, but they moved nicely,checking the plug color is difficult for me ive been able to do it a little bit but not getting much variety from the adjustments ive been doing. and i also dont know how to tell what kind of jettign i have.
 
88 yamaha 570 said:
i dont have tools to check float height, and i also dont know how to tell what kind of jettign i have.
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That's going to make fixing this problem really tuff.....

maybe there's a member that lives by you than can drop in and help.
 
88 yamaha 570 said:
well first of all theo, and blue, i removed the chokes, one cable was sticking and the other wasn't, switched to a primer and plugged the choke ports,
Click to expand...

IMO:

Sounds to me like when you removed the chokes, you probably removed the brass plungers.

I would think it would be very hard to plug the internal choke fuel passages with no plungers as they are normally held in their seats with a spring to close off their fuel circuit.

If the choke circuit is moving any fuel at all it would run "PIG RICH" no matter what else you did and definately would not pull any RPM or make any kind of power...sound familiar? I would suggest you ensure the choke plungers are installed with the springs in place, even if you are not using the the chokes and have the cables removed.

Another thing to check is the float level and the fuel inlet needles + seats to ensure they are set and functioning properly.

An item that can cause fuel mixture issues is the actual mechanical fuel primer...they can sometimes bypass fuel while the engine is running, but usually if this is happening they just run fat not as bad as yours is running.

JM.02c
 
ok time to clear up more information, im sorry i didn't give enough info, sideshow, i have the plungers in, im smart with mechanics but im not smart enough just yet to get this problem fixed, daman, im looking for people that live near me to help but i haven't even seen anyone on here that lives in New York at all and i also lost power a few weeks ago suddenly and checked compression and had 125 in each cylinder and found out my carb fell out of the boot because i didn't tighten it all the way, how do you check the float level without a tool, and how do i check the fuel inlet needles and seats? im going to pull the carbs off tonight and check it out, anyone know of a link where someone is doing a cleaning with my same carbs? ive seen carb rebuilds but i don't have some of the stuff in my carbs so its confusing, i still don't know if there is a screw inside the bowl or something for fuel that needs to be adjusted or are they all supposed to be snug? my carbs are the Mikuni VM38 by the way.
 
Just a bit of advice, "Dont get so offensive when people are trying to help you"

Anyways, I would see if any of your friends have a stock pipe and stuff laying around to see if it runs then, if its not clutched right for the pipe, they will sometimes perform poorly (My vmax had that problem).
 
STEERJOCK said:
Just a bit of advice, "Dont get so offensive when people are trying to help you"

Anyways, I would see if any of your friends have a stock pipe and stuff laying around to see if it runs then, if its not clutched right for the pipe, they will sometimes perform poorly (My vmax had that problem).
Click to expand...


X2, i dont know if you relize it but your comming off a little harsh!!. Go to babbitts.com. Follow the oem parts look up for your year and model of sled. It will give you a complete breakdown of the carbs. Then use the carb specs from the tech sheet to adjust your fuel screws and bowls ect... Take out all your mains and piolt screws. Their will be little numbers on them. Write them down and post back. I wont be sure it they are right with your pipes and such but someone will. Dont mix them up either. Post them as such. Carb by the clutch is PTO side, carb by exhaust is MAG side. My buddy has a 91 exciter and its stock but the carbs are a PITA. If i were you i would put the choke back to stock weather you use it or not. Keep at it youll figure it out. You dont need special tools for the floats. Just get a MM ruler and youll come out close if not exact. I stole one of my wifes sewing rulers with the little adjuster on it. works perfect for all my MM work. Cost $2 at a sewing shop. (had to buy her a new one)
 
On this site and many others there are carb cleaning how toos pinned. Do a google search. A lot of people have put together photos and how to do it. I think if you completly disassemble the carbs and clean everything you will be suprised. I think your problem is under the float arm. As someone has said all you need is a mm ruler(although I have flipped the carb over and looked at it and if it was level with the body-went with it) I would suggest getting the ruler though.
Mine would not run-bog out barely keep running(flooding out). Cleaned completely the float arm comes out with a prick punch(or a finishing nail in a jam). Don't hit too hard it can bend. Took out the needle and seat below and cleaned the rest. I set the screws where someone on line recommended. It ran beautiful after that. Well I am still a tad rich, but I am happy with it.
Now if I could only find a new skid for it!
 
ok 88 first did you put the springs and the brass plungers in for the choke? then seeing you have round slides with the floats attached to the bowl, you will have to get some clear fuel line about 8in. connect the line to the bowl drain and hold the other end up, with the drain open the fuel will fill the clear hose up to the level its set, then you measure from the fuel line in the tube to the base of the carb body and adjust from there. this can be done on a bench with a small fuel tank set higher than the carbs so they gravity feed. i dont know the spec but some one on here should, also depending on how you did your primer it may be giveing you fuel when you dont want it to, a primer inlet is usually smaller than a pilot jet, personally i would go back to the inricheners but thats me. and check to see that carbs are synced (move together,start and stop the same) and all the parts are in the carbs,main jets,washers,orings. your mains are in the bottom of the bowl i believe.
 
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