Author Topic: shifting issues (Read 2641 times)

MMICAFE · « **on:** April 29, 2009, 01:59:20 PM »

ok i have been having issues with my shifting for the past 3 days when i leave in the morning i warm up the bike for a while and i shift into 1st then i take off like normal and i get to a higher rpm's and shift into 2nd and the bike feels boggy and i slow down and it dies on me i have to fully choke it again and start it up then it bogs a little bit then runs absolutely fine please let me know whats wrong with my bike im trying to sell it

jeepster · « **Reply #1 on:** April 30, 2009, 06:06:47 AM »

Quote from: MMICAFE on April 29, 2009, 01:59:20 PM

ok i have been having issues with my shifting for the past 3 days when i leave in the morning i warm up the bike for a while and i shift into 1st then i take off like normal and i get to a higher rpm's and shift into 2nd and the bike feels boggy and i slow down and it dies on me i have to fully choke it again and start it up then it bogs a little bit then runs absolutely fine please let me know whats wrong with my bike im trying to sell it

Maybe you're not letting it warm up long enough?

MMICAFE · « **Reply #2 on:** April 30, 2009, 07:00:34 AM »

so is 20 minutes not long enough???

MMICAFE · « **Reply #3 on:** May 01, 2009, 03:22:07 PM »

guys come on i really need help with my bike

heffay · « **Reply #4 on:** May 01, 2009, 03:36:11 PM »

tell us more... bike,mods, location (altitude,etc.)

on your description... i'd say warm up too... but 20 minutes is plenty on an air cooled engine!

what have you done already? any differences in the way it runs?

Johnny5 · « **Reply #5 on:** May 01, 2009, 03:40:31 PM »

Has it had a tune up recently? What's the condition of the air filter? So many variables.

Sounds like a fuel delivery problem. Clean tank? Good fuel flow? Clean petcock?

MMICAFE · « **Reply #6 on:** May 01, 2009, 06:35:41 PM »

heffay: i live in phoenix arizona no mods (no money for them)
and when i start it up in the after class it runs like a top

Johnny5: it has had a tune up 2 weeks ago air filter is perfect and oem so no jetting issues
tank has been cleaned (kreemed) the petcock was rebuilt 1 month ago and yes there is good fuel flow new oil 3 weeks ago

Johnny5 · « **Reply #7 on:** May 01, 2009, 06:57:59 PM »

After you restart the bike, how long does it run well?

WHALEMAN · « **Reply #8 on:** May 01, 2009, 07:17:25 PM »

20 minutes in one place my bike would be getting very hot. I believe you have a carb problem. Dan

MMICAFE · « **Reply #9 on:** May 01, 2009, 08:47:12 PM »

well how could shifting problems be caused by a caruretor problem?

? tell me this i really wanna know $:-\$ $:-\$ $:-\$ $:-\$ $:-\$

mystic_1 · « **Reply #10 on:** May 01, 2009, 10:11:06 PM »

Doesn't sound like a shifting issue to me. More a lack of power, and dieing, when the engine is under more load. Possibly a fuel delivery problem, float levels too low?

BTW, what kind of bike is this?

mystic_1

MMICAFE · « **Reply #11 on:** May 02, 2009, 09:48:59 AM »

Johnny5
after leave the bike sitting for 3 hours i choke it start it up and run down the road and it runs perfectly

mystic_1
its a 1979 cb650 and the carburetors have been rebuilt float levels set to the recomended spec and how could the bike be dieing under more load considering i have all the same things on everyday then after class i just have me and nothing else on the bike

heffay · « **Reply #12 on:** May 02, 2009, 09:54:49 AM »

you are trying to apply reasons that don't matter.

so, my understanding is that...

you start the bike
warm it up
take it out get in first gear and it dies
start it again
runs perfectly

i've never known engines of any type be required to start once then shut down then started again to run properly.
quite an interesting problem.

i think you should go take it for another run... pay very close attention... and see if it does exactly the same thing.

so far that is not a shifting problem and sounds like a fuel related issue... possibly ignition

how many times total has this happened?

MMICAFE · « **Reply #13 on:** May 02, 2009, 07:29:49 PM »

well first off heffay i take it into 1st then start going then 2nd gear is when it dies i start it back up and gun it second i get to school after riding it 10 minutes and and let it sit for atleast 3 hours it runs fine after that just a little cam chain noise (normal for my motor) the carbs have been rebuilt as i said in a previous statement and it happaned all week all the ignition components have been replaced by the previous owner i have the recipts from when they were bought in june 2007

heffay · « **Reply #14 on:** May 03, 2009, 08:28:42 AM »

after sitting overnight is when the problem occurs. correct?
it dies immediately after starting out for the day... on restart you gun it? why? does it still not want to run?
but at this point it will run all day long. correct?

during warm up... does it idle well? do you have to keep it running or will it do that on its own?

MMICAFE · « **Reply #15 on:** May 03, 2009, 10:22:12 PM »

if it sits for a long period of time thats when the problems occur so yes and no but if i let it sit for a day and start it up and ride it in the afternoon it is fine. once it goes into 2nd gear in the morning is when the issues happen by gunning it i maen just take off and get going and yes it runs and yes afterwards it will run all day long it does idle perfectly but i dont know what the idle is as my tach doesnt work as for your last question i dont understand

Gordon · « **Reply #16 on:** May 03, 2009, 10:33:34 PM »

You sure your choke is opening all the way on that first run in the morning?

Everything you've described is a cold running issue, but since you say you warm it up for 20 minutes, a cold engine shouldn't be the problem.

Make sure your choke is opening all the way when you want it to after the engine is warm.

heffay · « **Reply #17 on:** May 04, 2009, 07:03:01 AM »

Quote from: heffay on May 03, 2009, 08:28:42 AM

do you have to keep it running or will it do that on its own?

= will it idle on its own for that 20 minute warm up? OR do you have to sit there and keep it running, yourself?

i agree w/ gordon... sounds like a cold running issue. (i have my doubts you let it warm up for 20, is this really true? if so, that is unnecessary on an old air cooled cb and wasteful)
like we just did the other day to mine... charge the batt, clean or replace the plugs, clean the carbs, time the ignition, check the valves and synch the carbs.... i'm betting it will purr like a kitten.

let us know if it does it today on the way to school... and make sure you drive it exactly the same way each time. we need to know precise actions and reactions.

mystic_1 · « **Reply #18 on:** May 04, 2009, 09:18:27 AM »

If the bike NEEDS a 20 minute warm-up before it can be driven at all, that's a sure sign of a problem in and of itself.

In fact 20 minutes of idling in one place sounds dangerously TOO long to me.

Are you turning off the choke before you try to drive off?

BTW in reference to my earlier post, idling = no load on engine. Driving = load on engine. Doing the ton = heavy load on engine.

mystic_1

KRONUS0100 · « **Reply #19 on:** May 08, 2009, 07:01:54 AM »

Hey Guys, just a quick note. If he lives in Pheonix........and its a morning only problem..........condensation build up in the intake tracts. I live in Indy area and when my bike sits out all night in the heat of summer after hard days ride, it does the same thing the next morning. Foggy mornings are the worst. Burns out after a short while. Try holding first gear a little longer going down the road....keep rpms to about 28-3500 for about 1/2 mile. wont hurt the bike.

Soos · « **Reply #20 on:** May 08, 2009, 08:05:57 AM »

Quote from: MMICAFE on May 01, 2009, 06:35:41 PM

heffay: i live in phoenix arizona no mods (no money for them)
and when i start it up in the after class it runs like a top

Johnny5: it has had a tune up 2 weeks ago air filter is perfect and oem so no jetting issues
tank has been cleaned (kreemed) the petcock was rebuilt 1 month ago and yes there is good fuel flow new oil 3 weeks ago

By perfect air filter, when was it bought and initially installed?
over a year?

Have you looked into your tank to make sure the liner is not coming apart(have seen this, don't know why it happens...)
try to scratch it with your fingernail. if it is hard, good.
if it is soft, or peels, get that taken care of quick.(as well another carb cleaning may be needed)

have you pulled off any of your floatbowls to inspect for anything collecting in the floatbowls?
On your '79cb650 the #4 carb would be easiest to get the bowl off.

What is the gap of your spark plugs, do they look sooty, or tan colored?

Have you "weatherized/waterproofed" your electrical system?
I personally go through every connector in the electrical system sanding all mating connectors, and apply di-electric grease.
Even in your climate, you don't have to worry about water, but oxygen will corrode your connectors as well.
30 years of corrosion in a electrical harness will lead to "funky" hard to diagnose engine running conditions.

You have the PD50 carbs, right?
When was new parts last put in? Have you replaced either your acelerator pump diaphragm or the air cutoff diaphragms?

Where did you get a re-build kit for the tank??
Mine is riveted together. Who did it for you?

Getting these older 650's to run right can be a challenge.
Sorry to hear you are trying to sell it.
If I had the $$ and you were closer I would buy it, I'd love to park another '79 in my garage!

l8r

News:

Author Topic: shifting issues (Read 2641 times)

WHALEMAN