Topic: 1980 Cb650 Custom Hard Starting

[Kraken]

First time here so let me say Hello All . OK i bought this bike about 6 months ago its a 1980 CB650 Custom for about 800$ its my first bike and must say i cant stay off of it  well that's till just a few days ago i went out to start it and let it warm up all it does is turn over.. so the fun starts i pulled the carbs off and went over them to find nothing.. I'm getting spark and the bike will run if a spray starting fluid in to the breather but it takes several tries before it will catch and idle once the bike is hot i have no issues . can someone shine some light on this as I'm dumb founded.

[davesee]

i've been through some hard starting episodes with my bike as well. there is sort of a ritual to starting it, and once the carbs come off and go back on, the ritual changes slightly. my first ritual involved a lot of throttle twisting to get it started (with choke), then for a while the same ritual resulted in flooded engine, making starts impossible. now i know to turn the idle screw a few times, pull the chocke and hit the button.

you may want to check your petcock and tank to carb fuel line as well. if both of those flow freely, check that the carbs are truly getting fuel by draining the carb bowls.

another suspect is battery voltage. a slightly weak battery can change the whole ball game on this bike.

[Kraken]

I'm getting fuel to the carbs

And i charged the battery even used the charger on the bike it just turns over

If i pull the choke any it just bogs down like i was flooding it. it was running great till i pulled the carbs the day before because i was getting air from some where making the bike run funny come to find out the fuel/air needle on 4 had come out (still dont know how) so i replaced it but after that its been down hill. after i pulled the carbs again i turned the air/fuel needles out from the 2 1/8 to just 1 1/2 didn't change anything . i even did a ohm check on the bike and got the right reading so it says in the Haynes.

[davesee]

i know my bike won't start cold under any circumsances without choke. the 650 is pretty cold blooded because it runs lean.

did you take anything apart when you took the carbs out ? (i once put the floats back in upside down).

another good idea is to check for leaks around the intake boots, as  the rubber gets pretty dry, and might not seal properly if you've taken the carbs off.

another thought would be to check a plug quickly after a start up attempt to see if fuel its  getting wet.

[Kraken]

so i went over the bike and checked the boots no cracks and i made sure all the straps where tight.

no the floats are in right but yes i did take the carbs apart to check all the little holes and make sure i didn't have any junk in them none to be had.

i went out today after work and with the gas off tried to start it to no avail so i got the starting fluid and sprayed some in the breather and she fired up with no choke ran for a sec and died so i did it once more and pulled the choke out when it started it kept running even went around the block with out warm up which is strange giving any other time it would have died on me.

so the bike will start run but only if i fire it  up with starting fluid sounds like my first car back when i was young 

[davesee]

when i first got my bike, the ritual was to pull the choke all the way out, then give the throttle a few twists, turn the idle screw way up, then hit start and give half a twist to the throttle.

have you checked the choke linkage at the bottom of the carbs? i've  re-installed the cable incorrectly before, and the choke feels right, but isn't actually functioning right. sometimes it's not the cable itself, but the way the (platic) choke cam is positioned is incorrect. this was buggered on mine once, and i ended up with the exact issue you're having.