rejet gone wrong, help?

nightrider011... · L Plate Warrior Joined: 21 Apr 2016 Karma :

so basically i own a sinnis apache 125 15 plate and i wanted a little more top end because i do a lot of dual carriage riding.

my bike topped out at exactly 60 so i heard a few people have gone 1 tooth up on the front sprocket from the stock 15t to a 16t for longer gearing and a sport exhaust with a rejet(main jet) from the stock 97.5 to the 105 so i did all of this.

before the upgrades my bike hit 60 no struggle now there is no power in 5th it actually looses power and screams when it gets to 60 eventually. A friend did the same and got 70 out of his no problem, my bike makes a bang when its first started on a morning and feels more sluggish than before, what have i done wrong??

thanks

P.addy · *Formerly known as* P. Joined: 14 Feb 2008 Karma :

No bikes are identical.

Put it back to how it was and do 1 thing at a time and work with that.

nightrider011... · L Plate Warrior Joined: 21 Apr 2016 Karma :

i did but i have the same problem, there was a screw on the bottom of the carb on the cylinder side that i thought was my idle screw but then when i found out it wasnt i couldnt remember how many turns id turned it, what does it do what could that be it?

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Why do people mess around with perfectly working bikes? Rolling Eyes

____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

nightrider011... · L Plate Warrior Joined: 21 Apr 2016 Karma :

um dont want to be rude in any way but i need help and suggestions not criticism because i am learning like many experienced mechanics did before they became experienced. you have to start somewhere.

The Shaggy D.A. · Super Spammer Joined: 12 Sep 2008 Karma :

Rogerborg · nimbA Joined: 26 Oct 2010 Karma :

Going back to stock is always a good idea. Whatever you do, don't just start throwing more "performance" bits at it in the hope that it'll get faster. In particular, a cone air filter is as likely to harm as to help.

Suntan Sid · World Chat Champion Joined: 07 May 2009 Karma :

Rogerborg · nimbA Joined: 26 Oct 2010 Karma :

stevo as b4 · World Chat Champion Joined: 17 Jul 2003 Karma :

OP changing gearing by +1tooth on the front sprocket is a reasonable experiment and easy to change back if it makes the bike worse to ride.

A straight through noisy silencer, not a great mod, but dem kids all do it anyway so join in or feel left out I guess.

But a relative noob having a go at re-jetting a carb that they know nothing about, are not familiar with all its parts and settings as std, and worse going on what a possible clueless mate told them, well that's just full of fail!

I might play around with jetting on s four stroke if I had modded a bike and thought it wasn't running right after or had flat spots etc. But I'd need to know the carb, how it all works and what the Base settings are too. And after all that you don't know slightly rich from slightly lean, by sound or how it rides. If you want perfect Carburation you need to know the fuel ratio your running, and also what that particular engine likes best.

The dyno is your friend generally, not a twatty mate.

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

Remember, top speed claims for 125s are generally lies.
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nightrider011... · L Plate Warrior Joined: 21 Apr 2016 Karma :

right so ive been on my friends bike and the speedo does indicate 70, so i had another look at m bike and maybe its getting too much fuel 105 may be too big so im going to put the stock 97.5 back in and see what happens i dont want my bike fast i want it to keep up to the max speed limit for the uk.