major problem ????

[epic]

Hi all , i think i have a major problem with my 125 i started it today with the choke on and it revved so much i thought it was going to blow up i quickly killed it as i was scared it would damage the newly rebuilt engine..

facts - newly rebuilt engine ,allspeed exhaust with about half the right amount of packing in it ,12a carb with std airbox and premixed fuel in the tank.
I'm not what you'd call mechanically minded so ive done some reading on the net but all i can find out is that the throttle cable could be stuck or there could be an airleak somewhere ,not really much to go on

Any ideas as to what the hell is wrong with it ill be much appreciated

cheers
Paul

[blue2smoke]

check you have put your carb slide in the right way around,

Back off your tickover screw

Check your throttle cable is moveing freely and not snagged,

You could remove the carb whilst kept intact to see if your gold slide is sitting on the bottom of the slide base, looking through the airbox intake

[epic]

Feb 28, 2011 13:12:33 GMT 1 blue2smoke said:

check you have put your carb slide in the right way around,

Back off your tickover screw

Check your throttle cable is moveing freely and not snagged,

You could remove the carb whilst kept intact to see if your gold slide is sitting on the bottom of the slide base, looking through the airbox intake

I'm pretty sure the slide seated right but i'll check it out as you suggest, the cable is free and has some slack as it supposed to i've not tried the idle screw yet but i'll try anything if it means avoiding taking the carb off again my knuckles haven't healed from the previous time

cheers blue

[epic]

Feb 28, 2011 21:17:08 GMT 1 garyrdrobbo said:

Feb 28, 2011 13:23:58 GMT 1 epic said:

I'm pretty sure the slide seated right but i'll check it out as you suggest, the cable is free and has some slack as it supposed to i've not tried the idle screw yet but i'll try anything if it means avoiding taking the carb off again my knuckles haven't healed from the previous time

cheers blue

easy......just remove the airbox rubber and poke ya finger in to feel if slide can be felt at bottom. ;D

To do that i'd have to push the rubber into the airbox then somehow put it back , which is a pain in the arse as the rubber is old and brittle I've got a ram-air comming in a couple of days so i'll be able to do away with the whole airbox and the carb will come out without the ho ha.
I get the impression that people in the know don't like a different airfilter is there a reason for this? Is it wise to run a bike in with a ramair on ?

[blue2smoke]

nowt up with pod filters , each to there own but you may need to do some fine tuning on jets/needle, sometimes you gain a little othewise you'll lose , each motors different .
Cannot hurt to try, just check your plug & jetting.

An easy way for the moment, pull your carb off and check all is seated correctly, whilst doing that put the airbox rubber on a radiator to warm it up and make it soft.

should be a doddle then to put back on then......

[epic]

Feb 28, 2011 21:46:33 GMT 1 blue2smoke said:

nowt up with pod filters , each to there own but you may need to do some fine tuning on jets/needle, sometimes you gain a little othewise you'll lose , each motors different .
Cannot hurt to try, just check your plug & jetting.

An easy way for the moment, pull your carb off and check all is seated correctly, whilst doing that put the airbox rubber on a radiator to warm it up and make it soft.

should be a doddle then to put back on then......

The only way i could get the carb on in the first place was to put the rubber in warm water for a while so i'll do that again ..

I pressed down on the slide quite firmly and it seemed to go down a little bit further than before , i'll try to start it tomorrow
as for the pod can i do a plug chop when i'll be having to run the bike in when i finally get it going? I thought you have to give it a bit of a thrash through all the gears to do a chop..

[blue2smoke]

Try to get it running right 1st with the airbox , then thats one problem out of the way.

Then run it in for a while , you can then go for whatever you want..

i like to sort little problems out 1st before i create anymore ,,lol

btw , your slide will fit bothways on your carb But ONLY reach the bottom with the cut out fitted correctly
if you get me drift............

[lc king]

the best thing you can do is rip off the standard air box and stamp on it, you dont need to be messin around with hot water and radiators!!!! buy a proper air filter and jet up your carb. have you checked that where the throttle cable splits for the oil pump it might have jumped out of the plastic joiner, making the cable shorter! also pull back the throttle and let it snap shut and you should hear the slide hit the bottom of the carb, if not, adjust it!!

[epic]

Feb 28, 2011 22:06:03 GMT 1 garyrdrobbo said:

Feb 28, 2011 21:55:17 GMT 1 epic said:

The only way i could get the carb on in the first place was to put the rubber in warm water for a while so i'll do that again ..

I pressed down on the slide quite firmly and it seemed to go down a little bit further than before , i'll try to start it tomorrow
as for the pod can i do a plug chop when i'll be having to run the bike in when i finally get it going? I thought you have to give it a bit of a thrash through all the gears to do a chop..

pods are ok but i hate ther induction roar and the unrestricted 10w bike runs best with the airbox.....i have one and done the experiments.

as for the rubber norbo does them and not that dear to buy new tbh but agree they are a fooka to fit when old.

chop's can only be done best when bike is run in.....nail it in top full throttle openit wide open...clutch in and kill engine together and coast to a stop will be the only true test of mixture tbh....

Gary i bloody missed a 10w carb on ebay a few days ago , the misses wouldn't let me buy it as i'd recently got a new fairing and micron forkbrace at some expense ..In hindsight i should've forgot the brace and got the carb ::)I'll check norbo when funds allow as i'm gonna be needing a few things from him anyway..

cheers

[lc king]

i have road my bike with a k&n type filter for years in the rain and it still pulls a tonne!! the sound of an air filter and a micron go together well!!

[epic]

I've not stopped stroking the brace yet ;D so no you can't have it ..

When i can i'll part with cash for a 10w carb off ya though as i'm 14 plus stone and think i'll be needing one...

I've made up my mind about the filter as i've got the ramair on it's way but i won't get rid of the std box as yam were the ones to put em on ..

Just my luck that the pods are effected by the wet ,it's england after all

[epic]

Feb 28, 2011 22:11:14 GMT 1 lc king said:

the best thing you can do is rip off the standard air box and stamp on it, you dont need to be messin around with hot water and radiators!!!! buy a proper air filter and jet up your carb. have you checked that where the throttle cable splits for the oil pump it might have jumped out of the plastic joiner, making the cable shorter! also pull back the throttle and let it snap shut and you should hear the slide hit the bottom of the carb, if not, adjust it!!

I won't be stamping on it but they do piss me off ;DI think i can hear the slide hitting the bottom , i'll check it all out in the morning
Cheers

[epic]

Right , i've made sure the throttle slide is seated properly , checked the cable and she still just revvs like she wants to end it all ,she aint the only one .any ideas??

[lc king]

i had this problem when i tried to fit a 175 carb to mine, have you checked that the needle is going far enough into the main jet. you will have 3 slots ontop of the needle to adjust it.

[LC'Adam]

Does it only rev high on choke? Have you tried starting it without?

I had a yz that used to cold start on choke at 8000rpm, never had a problem with it though, would settle down after a few seconds.

Could be a circuit in the carb that is blocked.

Screw out the tick over screw as far as it can come, set air screw to 2 turns out. Start her up with no choke.

Report back.

Adam.

[epic]

Mar 6, 2011 14:51:02 GMT 1 LC'Adam said:

Does it only rev high on choke? Have you tried starting it without?

I had a yz that used to cold start on choke at 8000rpm, never had a problem with it though, would settle down after a few seconds.

Could be a circuit in the carb that is blocked.

Screw out the tick over screw as far as it can come, set air screw to 2 turns out. Start her up with no choke.

Report back.

Adam.

Just tried that adam and she wouldn't start without the choke on ,she never has .I'll take the carb out and get some carb cleaner in it and blow it with comp air then try again..It was fine when i left it a few months ago so it could be something from the fuel tank that has blocked the carb

[Deleted]

if yamaha spent 'millions' on r+d to get the perfect set up with the air box, how come leon moss (rip) spent a 'fiver(?)' developing the ledar kit which is 100% better.........

i do like pod filters, the 'roar' is great and if used correctly with the air filter oil, can be used in all but submarine weather......

each to there own..........

[JonW]

Well the theory is that Yamaha had all sorts of noise and other tests to pass and used the airbox as part of that, the other end is the exhaust. Changing them to those without restrictions often opens up bikes, but not in very case...