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rebuilt carbs-great start- and then two days later-no good

Fuel System: Gas (Petrol) tanks, Carburators
allthumbs
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Posts: 131
Joined: Tue May 06, 2008 7:33 am
Location: Beacon, NY

rebuilt carbs-great start- and then two days later-no good

Post by allthumbs » Thu Sep 18, 2008 7:39 pm

I thought I'd throw this up before I take it all apart again to see if anyone else has had similar problems and can suggest a fix.

I rebuilt my Cb77 carbs last week, set the timing and started her up. Ran great, I mean I got rid of the problems with idle and popping I've had before. It just ran really smooth.

I mixed up a new fuel mixture I read about too: high octane, stabil, lead additive and 50:1 2 stroke oil.

Ran great. smoother than ever. I went for a ride and it was spectacular

then I noticed the petcock was leaking at the threads to the talk. It had been working itself loose overtime so I drained the tank and removed the petcock. I took it apart and cleaned it, then reassembled it onto the tank with thread seal for fuel fittings.

today Filled the tank and went to start it. usually it starts right up with 3/4 choke, 1 or 2 kicks. I kicked it maybe 30 times before I got a spark. then I closed the choke all the way and it started. I revved it to 3k rpm for a minute maybe then tried to open the choke a bit and it died. went through it all again, full choke and start-after 10 kicks. revved it for a couple of minutes this time and tried to open the choke, died. anything other than full choke kills the motor.

eventually during the period where the choke is fully closed and I am revving it to 3-4k, it will start to die so I open the clutch a bit and it comes to life for a few seconds. then I open it up a bit more and it dies.

Have a put too much crap in the fuel? have I clogged my lines with something?

I did notice that the screw on the edge of the float bowl case was leaking a bit of yellow liquid. If anything this should be fuel but it is greasier, the 2 stroke oil? I made sure the screw was tightly closed so no more leak.

purely stumped. maybe I should have left the fuel alone.

anyway, if someone can help I would appreciate it for sure.

mike69
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Posts: 193
Joined: Wed Sep 03, 2008 3:54 pm
Location: pa.

rebuilt carbs

Post by mike69 » Thu Sep 18, 2008 7:47 pm

Is there enough fuel in the float bowls? Sounds like it's not getting enough gas.
66 Dream
78 Goldwing

allthumbs
honda305.com Member
Posts: 131
Joined: Tue May 06, 2008 7:33 am
Location: Beacon, NY

Post by allthumbs » Thu Sep 18, 2008 7:50 pm

I'll check in the a.m. but I believe they are full because I had one bowl on wrong and had to take it off- it was full-to the top----------too much?

allthumbs
honda305.com Member
Posts: 131
Joined: Tue May 06, 2008 7:33 am
Location: Beacon, NY

Post by allthumbs » Thu Sep 18, 2008 8:01 pm

but yeah, it does seem like it's not getting gas

LOUD MOUSE
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Posts: 7818
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Re: rebuilt carbs-great start- and then two days later-no go

Post by LOUD MOUSE » Thu Sep 18, 2008 8:49 pm

Now that that the engine has some time on it ya now need to check the timing. (POINTS)
((((((((((Ran great. smoother than ever. I went for a ride and it was spectacular)))))))))) ............lm
allthumbs wrote:I thought I'd throw this up before I take it all apart again to see if anyone else has had similar problems and can suggest a fix.

I rebuilt my Cb77 carbs last week, set the timing and started her up. Ran great, I mean I got rid of the problems with idle and popping I've had before. It just ran really smooth.

I mixed up a new fuel mixture I read about too: high octane, stabil, lead additive and 50:1 2 stroke oil.

Ran great. smoother than ever. I went for a ride and it was spectacular

then I noticed the petcock was leaking at the threads to the talk. It had been working itself loose overtime so I drained the tank and removed the petcock. I took it apart and cleaned it, then reassembled it onto the tank with thread seal for fuel fittings.

today Filled the tank and went to start it. usually it starts right up with 3/4 choke, 1 or 2 kicks. I kicked it maybe 30 times before I got a spark. then I closed the choke all the way and it started. I revved it to 3k rpm for a minute maybe then tried to open the choke a bit and it died. went through it all again, full choke and start-after 10 kicks. revved it for a couple of minutes this time and tried to open the choke, died. anything other than full choke kills the motor.

eventually during the period where the choke is fully closed and I am revving it to 3-4k, it will start to die so I open the clutch a bit and it comes to life for a few seconds. then I open it up a bit more and it dies.

Have a put too much crap in the fuel? have I clogged my lines with something?

I did notice that the screw on the edge of the float bowl case was leaking a bit of yellow liquid. If anything this should be fuel but it is greasier, the 2 stroke oil? I made sure the screw was tightly closed so no more leak.

purely stumped. maybe I should have left the fuel alone.

anyway, if someone can help I would appreciate it for sure.

allthumbs
honda305.com Member
Posts: 131
Joined: Tue May 06, 2008 7:33 am
Location: Beacon, NY

Post by allthumbs » Thu Sep 18, 2008 9:11 pm

well if it is the timing i bet the screws on the plate have slipped. the threads were looking tired. do you happen to know the thread size on these? seams no one local cares to stock a gauge.

thx

LOUD MOUSE
honda305.com Member
Posts: 7818
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Fri Sep 19, 2008 8:07 am

The area which the cam rotor rubs against wears away.
That's the usual reason the timing changes. ..............lm

allthumbs wrote:well if it is the timing i bet the screws on the plate have slipped. the threads were looking tired. do you happen to know the thread size on these? seams no one local cares to stock a gauge.

thx
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