A forum for owners of Yamaha TTR250 trail and enduro bikes!

Members Login
Username 
 
Password 
    Remember Me  
The TTR250 FAQ web pages -> TTR250 -> Carb stuff -> carb needle adjustment
Post Info TOPIC: carb needle adjustment
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
carb needle adjustment
Permalink  
 

hi just wondering how hard it will be to adjust the main jet needle to 30mm as per staintune exhaust recommendation for installing slip on?



__________________

Prison, if you build it, they will come.
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
Permalink  
 

Regarding moving the needle up a clip or two, is this hard? apparently it should be at 29-30mm. any idea what it would be now at stock?

 



__________________

Prison, if you build it, they will come.
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
float needle adjustment
Permalink  
 

if you type TTR 250 staintune into google, its the second link down. i would have linked it but its a document. the instructions are there. if someone can read the part about moving it to 29-30mm and let me know which part they are talking about that would be great.



-- Edited by davecambo on Friday 3rd of February 2012 11:09:57 AM

__________________

Prison, if you build it, they will come.
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
raising / lowering needle clip
Permalink  
 

is it possible to raise/lower the clip on the jet with the carb on the bike or is it a complete disassembe deal.

can this be done on the fly by removing the top of the carb? if you remove the tank or loosen the screws on the rubbers can you rotate the carb to have access to the needle?



-- Edited by davecambo on Monday 27th of February 2012 12:57:06 AM



-- Edited by davecambo on Monday 27th of February 2012 08:36:16 AM

__________________

Prison, if you build it, they will come.
truslack


Veteran Member

Status: Offline
Posts: 75
Date:
Permalink  
 

I can't think of ANY bike where you could move the needle circlip by removing the float bowl. It IS possible to remove the needle with the carb slackened and tilted to the L/H side - though I find it more annoying and time consuming that removing the carb, changing it then refitting the carb.

Mark

__________________

Current: Suzuki RG 125 Gamma, Armstrong MT500, MZ ETZ300, Triumph Tiger 885i, Kawasaki GTR1000, Kawasaki GPZ750, CZ175 Trial, Yamaha TTR250 Raid
Tomorrow's just another day.
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
quick way to adjust needle clip
Permalink  
 

I just thought id let you all know that i was able to lower the clip on the carb needle in under half hour.

I removed the tank, and loosened the screws holding the rubber manifolds to the carb, so it was able to be turned 45 degress. I was then able to access the top of the carb easily with a screwdriver and needle nose pliers.

i had the clip adjusted and the whole thing back together under half hour, rode up to 120km/h and it was very nice. there was no searching at low revs like i noticed before.

going to take it up a few mountains on friday and will go from 1200m above sea level down to 0, so ill see how it goes in that elevation range.

i recommend this way to access the needle, as this was my first time inside a carb and found it very simple.



__________________

Prison, if you build it, they will come.
LRJ


Senior Member

Status: Offline
Posts: 158
Date:
Permalink  
 

Very nice, Dave. When you say "searching" at low revs, what exactly do you mean. In which direction did you adjust the needle?

Thanks,

Larry

__________________

Take time to play.

Central California, U.S.
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
Permalink  
 

i just noticed mine was sort of wanting more at low revs. not exactly a flat spot, dont know how else to describe it. sorry.
i adjusted my clip down one on the needle, hence making the mixture richer. i noticed it very much.

__________________

Prison, if you build it, they will come.
rhughes43


Newbie

Status: Offline
Posts: 3
Date:
Permalink  
 

So I pulled my carb and pulled off the top.  MY question is how do you get the slide to come up so that you can change the clip position?   I didn't want to completely disassemble everything so I stopped and thought I would ask someone who's done it before.  I've included a picture of the slide at the highest position with me holding the trottle open.  

 Thanks for your help.

photo (100).jpg



__________________
brindabella


Senior Member

Status: Offline
Posts: 168
Date:
Permalink  
 

re: getting the slide out..

the manual says you should first loosen a lock screw on the spindle at the top left in your photo, but this is tight and easy to strip. instead (if you can't loosen it easily), make sure all the throttle stop screw are set so you can turn it by hand to raise the slide as far as possible, and then the slide can come out (but only, of course, after you remove a couple of very small slot head screws that have to be taken out to disconnect the slide from the lever mechanism at the top, and then the little crank arm can be folded up out of the way and the slide lifted).

careful with the c-clip, it is delicate.

are you making it leaner (like me, on stock standard new bike, used well above sea level) or are you making it rich (like most other people, especially those with hacked air boxes and mufflers). rich = clip lowered, so needle raised)? tell us the results please.

see also posts at http://ttr250.activeboard.com/t47697675/more-carb-information/

 



__________________
rhughes43


Newbie

Status: Offline
Posts: 3
Date:
Permalink  
 

I got it out, lowered the clip to the next position (it was already in the middle) to make it richer and it ran like crap.  I then raised the clip to the next to highest position and it runs great.  The hesitation under part throttle is gone.  Everything I read said that the mixture would need to be richer to improve performance,  but it was just the opposite in my case.  



__________________
brindabella


Senior Member

Status: Offline
Posts: 168
Date:
Permalink  
 

Welcome to the "mean and lean" club!

out of interest, is your bike a standard US model (therefore presumably manufactured 2006 or earlier) with standard jets, and standard muffler and unmodified air box? and roughly what altitude are you riding it at?

__________________
Clutha


Veteran Member

Status: Offline
Posts: 79
Date:
Permalink  
 

Sounds like the same problem I've got. We used to call it 'hunting'

Out a couple of nights ago and it was bad at the start of my run when I was climbing in 1st or 2nd gear but on <25% throttle.

On my way home on flat roads the bike was performing really well on 50%+ throttle. I suspected some dirt in jets but maybe I'll try this trick 1stsmile



__________________
Haggis Hunter


Veteran Member

Status: Offline
Posts: 66
Date:
Permalink  
 

Hi Clutha. My TTR does the same on a light throttle and I would also describe it as hunting. I suspect that the idle jet may have a bit of muck in it. When I get a chance I will get it off and drop it in the ultrasonic bath, if there is any muck in there that should clear it. The bike is a 2005 with just over 1500 miles on it. When I picked it up a couple of weeks ago it had 1488 on the clock. It had only done 34 miles since the MOT in September last year!

I suspect the lack of use is the cause of the problem so I will go for cleaning the carb first and see if that makes a difference before I do anything else.

BTY I have a 1993 Raid with over 53,000 Miles/Km's on it. It is best described as 'well used' but it runs a treat on low revs, probably down to a worn carb that is running rich!

 

Peter



__________________
Clutha


Veteran Member

Status: Offline
Posts: 79
Date:
Permalink  
 

My brand spanking new one ran like a dream as you'd expect, but it had sat at the dealers for 3 yearsno

There must have been zero muck in the carb and I was surprised it hadn't gummed up. Sadly after it was stolen it was recovered but with a wrecked engine. Polis thought it been used for shifting drugs over waste ground in the north of Glasgow.

Anyway, the one I have now had a CRD exhaust fitted that would waken the dead, all for 1-2 more hp. The seller gave me the original which I quickly fitted to stay pally with my new 'mature' neighbours. Now we're good pals I might try the CRD again in case the carb was rejetted to suit



__________________
davecambo


Senior Member

Status: Offline
Posts: 236
Date:
Permalink  
 

it really depends on where abouts you live and the altitude. for me, at 700m where i live, and where i ride at 1200m, making my bike a bit richer made it perfect. NO ONE should tell you there is a specific place for the clip, as your bike will run completely different to the next persons.

__________________

Prison, if you build it, they will come.
mud


Veteran Member

Status: Offline
Posts: 34
Date:
Help changing carb needle clip please?
Permalink  
 

Hi, can anyone point me towards a guide or tell me how to change the carb needle clip height please? I've re-jetted the carb and fitted a twin air filter, but now I'm getting a bit of a stuttter on part throttle. Any help would be gratefully received!

Cheers Mud



__________________
texasT


Senior Member

Status: Offline
Posts: 227
Date:
carb needle adjustment
Permalink  
 

http://ttr250.activeboard.com/t55374798/rebuilding-a-ttr250-teikei-y30p-carburettor/

above.gif have you read this thread. It may help.



__________________

'04 TT-R250sc Blue model U.S.A.
mud


Veteran Member

Status: Offline
Posts: 34
Date:
RE: Help changing carb needle clip please?
Permalink  
 

Thanks very much Texas, job done yesterday and was not half as bad as I thought. I do love the simplicity of the TTR, is just like it's owner! Hopefully I'll get to ride it this evening.

Cheers Mud

__________________
texasT


Senior Member

Status: Offline
Posts: 227
Date:
Permalink  
 

Glad to hear you are back in the saddle mud.

 I was a bit timid myself the first time I tore into mine, as I have had issues with carb rebuilds in the past (General Motors "Rochester") but the stock TTR carb is pretty easy to work on and I made it through the task pretty easy with the help of these guys on this site.

greg



__________________

'04 TT-R250sc Blue model U.S.A.
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
The TTR250 FAQ web pages -> TTR250 -> Carb stuff -> carb needle adjustment


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard