JETTING??? help me please!!!

[djneu-trix]

Hi all

i just got my beast up and running at long last! done everything by the book and its all good! tons of copresion etc!

anyway it starts and idles revs too! but a soon as you get on it it judders and only goes about 5mph then it will cut out!

i got a ns125r-k and its now got the 170cc mallossi bb kit on it and bigger sprocket and all new jets/sliders and pin!

the kit came with 2 main jets! ive tryed both of them and the same happens with both i was wondering maybe it could be the small 1 or the giant 1 that goes down the middle???? i aint got a clue! im a complete novice!

i did a plug check after idle'ing it for 10 mins and the plug was just wet with a lil bit of black stuff on it! looked good to me! going by the hanes manual! so i dont think its oil bogging it down!
i thought it might be because i put quite a bit of oil on the piston when i rebuilt it but its been idle'ing for about 25 mins all together so i would have thought it would have burt that all off by now!??

im really suprised the bike started starght away after 3 kicks! (THANK GOD)

any help what so ever is really apreciated! i got to get it working by tomorrow night!


THANKYOU!!!!
____________________
pg

[Kickstart]

Hi

At idle the main jet is doing nothing. It doesn't come into play until about 3/4 throttle.

As you are just moving off and having it dieing I would suspect the needle jet needs playing with. Put the clip down a notch or 2 and try that (ie, nearer the pointy end).

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

right thanks i will try that tomoz!

if it aint that is there anything else you can think of as i can do it all in 1 hit then and dont have to wiat for some 1 to reply!!!

THANKYOU soooooo much for ya help!!!! if i could send beer over the internet i would be sending you 1 now
____________________
pg

[Kickstart]

Hi

If it is jetting related then essentially idle and tiny throttle openings is idle mixture, 1/4-3/4 is the needle and above 3/4 is the main jet.

There are other things it could be but start with the easy and likely ones first.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

cheers kickstart your a star!!!!
____________________
pg

[djneu-trix]

No luck

done the needle! and it was exactly the same!

then my m8 had a play with it! played with the idle screw and the other screw! (piolt)?

anyway! now it wont even start and the stupid twonk cant remeber how meny turns it was out! same for the idle screw!

i have read the hanes and it said to tune the (pilot) 2 and 1/8!
done that! no luck still wont start!

any idears on what i should do? (if not its going to the garage) but im getting fed up with relying on lifts and public transport! + i wana sell it and do me das!

cheers again for all help in advance!!!
____________________
pg

[djneu-trix]

forgot to say! when he was playing with it for sum reason when it sarted after he was playing with it it reved to about 5000rpm and then died!

dont know if that will help! it was allmost like the fuel was turned off! my old minimotos used to do it when the fuel was turned off!

thanks again
____________________
pg

[Kickstart]

Hi

Idle mixture screw either makes it ricjer or leaner, depending on which model of PHBH carb it is. For a start set it as specified in the manual (screw it fully in lightly, then back out that number of turns).

The idle speed adjuster is pretty much suck it and see. Has the same effect as holding the throttle open a tiny amount. Sounds like it is too far out if it instantly revved up to 5000.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

ok kool!
i was looking in the hanes and i cant find out about how meny turns idle mena be out! but the pilot turns are in there! i will keep looking and maybe if i cant find it i will screw it in all the way and just go out 1 turn!

anyway m8! before this screwing about with screw malarky started would they be anything to do with why it wasnt running propperly??

im gunna have 1 more go at it in the morning and if no luck im just gunna take it to the garage!

allso
would it be a good idear to put all the old jets back in and just change the main jet back? or is that a bad idear???

cheers again kickstart!
____________________
pg

[Kickstart]

Hi

DO NOT screw the idle speed screw all the way in and then out one turn. The further in it is the higher the idle speed. One turn out would put the idle revs through the roof.

Main jet only affects high throttle openings. Would doubt you had the throttle open enough for the main jet to be in play when you first had a problem.

Set the idle mixture screw to stock, and play with the needle jet.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

ok kool (glad i didnt )

so i should put it up 1 from the bottom (pointy end) now?
as it was 1 down from the top and now its right on the bottom 1!

thanks again!
____________________
pg

[Kickstart]

Hi

Yep, give that a try.

However, also check the reed valves are sealing.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

sealing??? whats that when its at home??? lol sorry!

im just reading this!

https://www.thisoldtractor.com/gtbender/dellorto_tuning_instructions.htm

im starting to understand a lil bit now!

fingers crossed i can get it going!

cheers i will keep you updated!
____________________
pg

[Odie]

[djneu-trix]

After taking the tank of 14 times and messing about with it loads its now up and running ! did a plug chop after a 5 mile ride and its a nice tan colour!

i found out it was just the main jet and that the circlip on the pin needed to be right at the top!

thank god its moving i really cant belive i did a whole engine rebuild with just a hanes and you lot!!!!!

thanks for every ones help that helped me with jetting and the rebuild on my cylinder! i couldnt have done it with out you!!!!


Pat on the back!!!
____________________
pg

[bish777]

IF the clip needs to be right at the top, maybe you should get a slightly smaller main jet?
____________________
GSXR1100J

[djneu-trix]

o right!

why you say that????

cheers
____________________
pg

[djneu-trix]

more help needed!

i got it running now! goes ok! but at about 5500 rpm it splutters and allmost sonds like its going to back fire! i done a propper plug chop and its looking really good! its a light brown!

i have been told it could be my reeds now! maybe i need carbon fiber ones that are stiffer!?!?!?

any more advice would be really apreaciated! as i have too do it myself!

i would take it to a garage for them to look at but theres only two down my way and as soon as i told them what bike it was and that it was a 2 stroke they said the couldnt be doing with the hassel! which is sooooooo wrong!!! bang out of order if u ask me! (They both said it)

Thanks again!
____________________
pg

[Kickstart]

Hi

Forget changing the reeds to carbon ones. Might make a tiny difference to performance / throttle response compared to normal fibre ones, but barely enough to notice and is not likely to help this problem unless the reeds in there are damaged. If they fail to seal then you will get all sorts of problems. Easy enough to take out and check them.

On a slide carb mixture pretty much depends totally on throttle position. For a plug chop you need to be at high revs / full throttle for a while. Normally best to find a steep hill so you can do this in a lower gear without going silly speeds. Once you have held full throttle / high revs for a while pull the clutch and hit the kill switch, coasting to a halt (DO NOT let the clutch out / start the engine until you come to a halt and have checked the plug).

So, basically also try to go past 5500rpm with different amounts of throttle.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

ive tryed different amounts of throttle and it makes no difference! still makes the funky noises!

i dont want to go to fast as ive only just built it and im running it in!

i wont bother with the reeds then! they wernt damaged when i put them back in! they looked top notch!

i was wondering if it was doing this because it hasnt warn the piston rings in yet! ive only done 30 miles so far!

cheers once again kickstart!
____________________
pg

[Kickstart]

Hi

Is the bike standard? What has been done to it? Has the ignition timing been checked?

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

[djneu-trix]

PLEASE HELP ME SOMEBODY!!!!!! AAAAAAaaaaaaRRRRRRggggggGGGGGGHHHHhhhhh!!!!!
____________________
pg

[Kickstart]

Hi

Which jets are you using now?

Cannot remember the main jet size on the NS as standard. Suspect it is around a 110. What main jets have you got with the kit? Is there a replacement needle jet?

To be honest, if it is running safely now (and rich is safer than lean) then I would be tempted to leave it as is for now until it is run in a bit.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[djneu-trix]

original is 110

kit came with 112 (tryed this 1 and no difference)

And 125 (ive got this 1 in as i thought it would be more resonalble)

yer it came with the needle and slider and needle jet and power jet!

the new needle has a thicker point than the old 1!

ive put everything all in!

ive takent them all out and put the old ones in 1 by 1 and ive tryed all the old ones! and then i put them all in 1 by 1 again! there all in again and its running best as is at the min.

ive had the circlip on every level possible and its second from the top and that it!

i think maybe your right! just keep running it for a lil while!

not unless you have any more idears?????????

cheers
____________________
pg