Help! Pitbike throttle issue!

[Mr. Spindle]

Hey guys, I know it’s been a minute, glad to be here again.
So I’ve got a problem with my (either) 1986 or 2006 Yamaha pw80 (yea, it’s a dirt bike)
I cleaned the carburetor out real good tonite and now when I kick (start) it it will immediately bust out on full throttle. Help please, this thing is a pain in the ***.
(Pics to come)

 

[mckutzy]

No/broken return spring, there is still dirt in there, throttle cable needs cleaning/greasing or is rusted....
Start with the carb and work back to the grip... that also might need some work/repair/replacement....

 

[mrbeggs432]

Maybe Check/clean your throttle grip cable assemby

 

[itsid]

obvious things first:
since you cleaned the carb, maybe you haven't adjusted the idle speed screw correctly?
close the air/fuel mix needle (clockwise until it bottoms out.. fingertight!!)
now open it back up 1.5 full revolutions (counterclockwise of course )

check the throttle cable end play (you should be able to rotate the throttle grip 3-5mm [~1/8-1/4"] )
the long metal hex part on the backside of the throttle grip
If you stand in front of your bike losen the locknut and rotate the adjuster upwards to increase the play, downwards to decrease the cable play.. retighten the locking nut aftwerwards.

and if that's all okay, check the plunger and the spring.

'sid

 

[landuse]

Return spring...throttle stuck in open. Throttle cable binding somewhere in open position....Basically what everyone has said

 

[Mr. Spindle]

Thanks for suggestions, again it is an old bike. Pic upload page is not working for my iPhone 6 right now, so I found the oem carb (the one on it) link:
Carb:

https://www.ebay.com/i/263057682517...3D711-117182-37290-0%26rvr_id%3D1482708623400

---------- Post added at 09:19 AM ---------- Previous post was at 09:10 AM ----------

As you can see, it is a nice Mikuni carburetor, which is nice... but do you think maybe I should replace the whole throttle system for like 50 bucks?
https://www.ebay.com/i/252322827548...3D711-117182-37290-0%26rvr_id%3D1482700325916

Some main problems in winter are the rusty bars (original) and the fact that I don’t have a muffler pipe.
Do you think the bars would interfere with the twist throttle?
I’ve gotta be honest, after cleaning that carb, the throttle is SMOOTH.
This is everything I did to it yesterday:
1: took everything apart so I could get to the carb
2: cleaned EVERYTHING
3: did not take any part of the carb apart except for the bottom of the float bowl
4: put it back together (slowly) as to not mess something up (did mess something up before i had to take it apart this time)
5:started it
6: turned it off due to extremely high rpms
And also, I have the original manual if that helps

 

[itsid]

Well, something you did.. otherwise it wouldn't act that way..

if you removed the carb from the engine, it's possibly just "side air"
from a busted, incorrectly installed or just not properly tensioned gasket (well untensioned manifold bolt that is of course)

So, to trace down the issue, trace back every step of your procedure (kneeling in front of your bike) and put your finger on every part and bolt you touched, then ask "could this be the issueß" and if in doubt check it, if confident it cannot be the cause.. check it and if you think it might.. check it
(you get the idea... check every single bit again!)

At one point you'll hear a dim clicking noise in your head.. that's when you found the cause

'sid

 

[Mr. Spindle]

Pics:
https://imgflip.com/i/27djjr
https://imgflip.com/i/27djls
https://imgflip.com/i/27djnd
https://imgflip.com/i/27djpi
(Please excuse the fact that I had to use a meme site to show these)
(Attachment button would not work because my dad messed with my phone)

 

[Randy H]

Did you take the slide out?

 

[Mr. Spindle]

Did you take the slide out?

Yessir

 

[Randy H]

I'd investigate the slide and it's operation carefully.

Open the throttle and let it shut hard. You should hear the slide.

Make sure the jet needle is going into the needle jet properly.

That's probably what itsid was talking about..plunger=slide?

 

[Mr. Spindle]

Okay, I can hear it plink inside the carb.... if it’s not that, what is it?.....




If only things were easily achieved..........

This just in: I decided to take the bike apart again and realized that the carb was a little wiggly.
I did not screw the right end of the carb onto the reed valve cover at all.
Could this be the issue?

 

[itsid]

...

if you removed the carb from the engine, it's possibly just "side air"
from a busted, incorrectly installed or just not properly tensioned gasket (well untensioned manifold bolt that is of course)
....

.... I decided to take the bike apart again and realized that the carb was a little wiggly.
I did not screw the right end of the carb onto the reed valve cover at all.
Could this be the issue?

You mean if side air could cause the issue... hmmmm let me think about that...

'sid

 

[bob58o]

What is "Side Air"?
Is this some 2 stroke thing I don't know about?

Or some sort of translation for "leak"?

 

[itsid]

I think technically correct you'd call it "false air"

and not only a two stroke thing no... but yeah a bigger issue with them (too lean, not lubricated, too hot, engine destruction)

'sid

PS sorry.. lingual issue.. Falschluft (technically correct) [false air] we call Nebenluft colloquially...
and well... translare humanum est

 

[Mr. Spindle]

Still doin it. Took a video this time. I can’t keep it running for long enough to get a good look at the carb during run...

 

[Mr. Spindle]

Maybe the float is stuck?

 

[Randy H]

Gee it looks like you've got everything clean as a whistle.

 

[Mr. Spindle]

Thanks for your support in this guys. I got it to work and then it blew up, but oh well.
Again. Thanks so much

 

[landuse]

Thanks for your support in this guys. I got it to work and then it blew up, but oh well.
Again. Thanks so much

I think we all need to hear what you did to blow the engine up!