[not2brekinwit]

Ok heres the deal. I just installed the head, piston, carb, aftermarket filter and cylinder off a 06 crf70 on my 07 crf 50. All went well with the install but the throttle cable was way too short so i had to get one custom made for longer length.



Now the problem i'm having is that the throttle is way too twitchy. When i'm wheeling in 2nd it seems like theres a ton of bricks on the front end as it doest even want to come up. The idle after i let off the throttle still goes for a split second ( like you can still hear it rev for 1 second after i let off)



IT seems like the gears run out way too fast so that may be the problem. I have +1 in the front and + 3 in the rear which pretty much evens it out so i'm pretty much at stock gearing. Could this be the problem? Should i go down a few like 2 teeth in the rear?



It seems like the bike is just not running like a crf70 should as it is a bit faster but it doest go through the gears that long and its way too twitchy compared to my fiddy.



Anyone can give me some insight to whats going on? I'm already considering the rear sprocket going -2 in the rear back down to 38 but i was looking for some answers to see if anyone could give me more insight on maybe some tuning or maybe if the answer to if the motor is suppose to run that way?

 

[not2brekinwit]

clutch primary gearing is different from the 50 to 70...just put a 15T counter sprocket on your hybrid

i already have a 15 tooth front sprocket on my bike. Is that what you meant?

 

[not2brekinwit]

well go to a 16

16 wont fit i dont think....unless i am wrong? also that will be three teeth up just like. Will i loose all of my low end?

 

[not2brekinwit]

also is that why my bikes idling funny and running funny?

 

[not2brekinwit]

probably have to adjust the air screw

i dont have one since my carb is a crf70 or is it somewhere else?

 

[not2brekinwit]

the screw thats next to the idle screw doest have a groove to turn it with anything.

 

[not2brekinwit]

well u have more with the bigger displacement...the clutch primary drive is inside the cases

what cases??

 

[not2brekinwit]

what carb are you using

stock crf70 carb

 

[not2brekinwit]

yeah mine didn't either at first. Just dremmel a groove in that thing. And my was an 06 too...

so whats the adjustment setting like? all the way shut then how many turns?

 

[not2brekinwit]

that is odd should be a air screw adjustment

there is one but its just not grooved. How do i set that?

 

[not2brekinwit]

put the clip on the needle in the middle spot b4 ya do it

what do you mean by this?

 

[not2brekinwit]

post a pic of that carb plz

heres the picture of the carb

 

[not2brekinwit]

your main jet needle on your carb slide

is that mandatory to do this? Can i just turn the air fuel ratio screw an adust it that way?

 

[not2brekinwit]

well it should be fine being that u took everything off a running bike...idk about those carbs tho...never tuned that style

but does this sound like the problem? or is it the sprockets?

 

[not2brekinwit]

you do have some type of carb issue,,,,,air leak or sumn...running out of gear is final drive ratio...you say you have a 15 front what is the rear

the front is 15 one above stock, and the rear is 40 3 above stock

 

[not2brekinwit]

I am running 15/37 on my daughters bike it has a 88 kit and ported head and that thing has mucho torque and does not run out of gear

but remember that its a 70 NOt a 88. What do you think if i run a 38 in the rear?

 

[not2brekinwit]

well ya need to get the engine running correctly first

do i start going right with the fuel screw or left? i mean to close it all the way. Is that all the way right or left?

 

[not2brekinwit]

right is in

so i start all the way right then go 1/4 turn lefts?

 

[not2brekinwit]

to start anyway...turn ur idle up so it will idle cuz it will probably run like poo...turn the air adjust screw out till it idles the fastest and then back in just a bit...if it never changes then ya have jetting issues or the pilot is dirty

i just turned it right all the way and turned it 1/4 turn so far and it seems like it runs way better

 

[not2brekinwit]

well then ya may be on track

ok well after adjusting it and stuff now my bike has no power at all. It revs out in first half way and theres no pull. Every gear is dead. No power.



What do i do?