Custom Fighters - Custom Streetfighter Motorcycle Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1
just picked up my first bike (78' cb400) which i plan to customize much like the "wtf bike" that's listed somewhere in this forum. They guy I bought from took good care of it - but since I've been riding it my buddy and I both notice some serious hesitation in the lower RPM range. I am completely new to bikes, but am willing to try some easy to moderate mechanical stuff. Where should I begin?

will post pics soon
 

·
Where's the keg at?
Joined
·
145 Posts
Welcome to CF. I have heard of guys doing there own chemical bath by using straight Pine-Sol and letting their carbs sit for a day or two submerged. I think theres a thread somewhere on here about it.
 
  • Like
Reactions: thaOrleanyte

·
watches you sleep.
Joined
·
9,116 Posts
Welcome to CF. I have heard of guys doing there own chemical bath by using straight Pine-Sol and letting their carbs sit for a day or two submerged. I think theres a thread somewhere on here about it.
I've heard of this too, but the last thing you wanna do is think your carbs are cleaned because they sat in a vat of pinesol, and your bike still wont run properly but you overlook the carbs thinking you already took them out the the equation...by the way, welcome to Custom Fighters.
 

·
ShamanFighter
Joined
·
22,340 Posts
sounds like a partial clog. try some seafoam.
 

·
ShamanFighter
Joined
·
22,340 Posts
if not

ur best friends in Carb Country are

Compressed air.

Guitar string G or B.

Carb cleaner. a carb solution vat if possible but pinsol should work.

grease for the boots.

carb part names: Jet, Pilot Jet, Jet Needle, Float , Float valve. diaphragm, Float bowl, Float Bowl Drain Screw. as well there are o-rings and and gaskets (which are all RUBBER) and springs. im sure im missing things
take note of how the parts come out where they came out from. hoses included.
when u pull the pilot screws take note of how many turns they turn in and then go all the way out with them.

take the mother fuckers apart down to the bones, remove all rubber i repeat all rubber.
do not separate the carb banks EVER.
theyre a bitch to take apart and put back together right.
soak all needles jets jet needles, floats carb bank in cleaner for 1 hour to 24 hours depending on how bad they are.
( this chemical will Fuck up the rubber so be sure its all removed.)
then pull all the parts out.
spray dry them with compressed air, then take all the jets and run the guitar string thru them even the holes in the emulsion tubes.
then spray all parts with Spray Carb cleaner and let it set in.
then air dry yet again.

now reassemble the badboys taking note along the way of how they came out where they came out. TAKE PICTURES IF YOU HAVE TO not everyone has Photographic memory. set your pilots to where they were

most carbs have 2-4 brass screws called jets in the carbs that atomize the fuel liquid into tiny tiny particles these more than likely are the Culprits to your problem that and passages in the carb body.

then reverse the order of operation. go back together with the som bitches. also clean or replace the air filtration device. the carbs to the manifold good n tite. then bolt the Air box to the carbs good n tite. get fuel flow to the carb bowls via tank or fuel bottle. use the drain screws to see if ur getting flow.

then turn bike on, pull choke and letter rip. (in neutral of course) (dont ask me how i know)

now a sure fire way to see if you got a air leak of some sort spray the rubber intake boots and around the air box with brake clean or spray carb clean and if the RPMs change ur a leakin and the ship wont sail properly. if the rpms stay the same your winning the game
 

·
ShamanFighter
Joined
·
22,340 Posts
You forgot to add then make a seat out of Tenderloin.
shit i fergiteded



i thought Tenderloin Seats free with all Registrations now
 

·
Cpt. Obvious
Joined
·
2,112 Posts
Welcome to CF.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #15
cleaned carbs with carb cleaner (the jets and such, i didn't submerge the entire assembly), but I'm still having the hesitation up to half throttle - then past half throttle the bike runs great. I've read a lot of info of problems with bikes bogging down past half throttle - i have the opposite. put in seafoam into gas. what should I try now?
 

·
Registered
Joined
·
30 Posts
Discussion Starter #19
ZOOM ZOOM! Pulled the carbs for the 3rd time last night, cleaned the hell out of them (again) paying special attention to the pilot jet needle and hole since I was having all my problems early in the throttle. Compressed air multiple times through all holes and lines as well as carb cleaner. Checked and rechecked the action on the slides, etc. etc. Adjusted pilot screws in a bit to allow more fuel or less air (the screws are near the front wheel so I think they are the fuel adjusters). Bottom line, after putting it all back on, I rode this morning and hallelujah! NO LEAKS, NO HESITATION, NO PROBLEMS! Except when I got pulled over for not having my plate on, lol, no big deal. Police escort home :)

Thanks for all the help everyone - I definitely know a shit ton about carbs now.

:letsride:
 
1 - 20 of 21 Posts
Top