Author Topic: '78 Wont Start  (Read 868 times)

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Offline Prez1967

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'78 Wont Start
« on: July 13, 2016, 07:55:06 AM »
Had the bike tuned up last year, rode it home just fine.  Started it every couple of weeks to ensure it was hibernating well.  Its been on a battery tender all winter also.

Its been about three months since I started it (had our second baby and lifes been busy).  I attempted to start it last saturday.  Fuel on, Switch to run, choke half way out (as ususal), starter button. Nothing.

I played with the choke a bit, sounds like it wants to start but its not happening for some reason.  Plenty of fuel in tank.

Any suggestions?

Wife and kids are still overseas on vacation until the end of August.  I'd like to actually ride the bike this year before they return and it gets parked for the winter again. 

Offline flybox1

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Re: '78 Wont Start
« Reply #1 on: July 13, 2016, 08:11:40 AM »
Remove and clean the carbs.
Assuming you have the correct PD carbs for your '78, probably some varnish there in the jets, and in the accel pump system.
Also, check that the fast idle cam is lifting the slides when the choke knob is pulled.
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Offline Prez1967

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Re: '78 Wont Start
« Reply #2 on: July 13, 2016, 08:14:12 AM »
Carbs were rebuilt last year before being parked

Offline flybox1

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Re: '78 Wont Start
« Reply #3 on: July 13, 2016, 08:20:13 AM »
Carbs were rebuilt last year before being parked
Glad to hear it, but my answer is still the same.

Who did the carb work?
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline madmtnmotors

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Re: '78 Wont Start
« Reply #4 on: July 13, 2016, 09:29:21 AM »
Carbs were rebuilt last year before being parked
Glad to hear it, but my answer is still the same.

Who did the carb work?

+1

A year is a long time, especially for ethanol laced fuel. Replace the fuel while you're having the carbs cleaned. Start the bike at least once a month to help prevent this problem in the future.
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Offline DaveBarbier

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Re: '78 Wont Start
« Reply #5 on: July 13, 2016, 04:23:51 PM »
Carbs were rebuilt last year before being parked
Glad to hear it, but my answer is still the same.

Who did the carb work?

+1

A year is a long time, especially for ethanol laced fuel. Replace the fuel while you're having the carbs cleaned. Start the bike at least once a month to help prevent this problem in the future.

If you're going to start it up, let it get to full operating temp under a box fan for a while. Water is a byproduct of combustion and you want it to get hot enough to evaporate it all.

Offline tlbranth

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Re: '78 Wont Start
« Reply #6 on: July 13, 2016, 05:56:33 PM »
Ethanol is horrible stuff. It'll suck in water in no time. When I park a bike, I put an appropriate amount of Stabil marine and run it into the carbs. Your problem is most likely water in the fuel and maybe gummed up jets. Clean things up and buy a big bottle of Stabil Marine.
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Offline MoMo

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Re: '78 Wont Start
« Reply #7 on: July 13, 2016, 07:14:51 PM »
before going to the work of removing the carbs turn the petcock off, drain the fuel from the float bowls by opening the float drains, turn the petcock back on and try again. I have started many bikes that have sat longer than yours by draining the float bowls....Larry  Also, do you have spark? Sometimes when a bike sits the points need to be cleaned

Offline Lostboy Steve

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Re: '78 Wont Start
« Reply #8 on: July 13, 2016, 07:24:47 PM »
I did my carbs about 2 years ago and even though it gets run at least once a month, it's time. A year sitting is a hell of a long time.
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Offline rotortiller

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Re: '78 Wont Start
« Reply #9 on: July 14, 2016, 03:26:50 AM »
What he said  ;D You should be able to use the kick starter with a low battery and/or US starter.

Quote
before going to the work of removing the carbs turn the petcock off, drain the fuel from the float bowls by opening the float drains, turn the petcock back on and try again. I have started many bikes that have sat longer than yours by draining the float bowls....Larry  Also, do you have spark? Sometimes when a bike sits the points need to be cleaned

Offline GetSchwifty

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Re: '78 Wont Start
« Reply #10 on: July 14, 2016, 08:53:48 PM »
I've got a 77 and those carb cleaning a aren't a joke. I let mine sit for 2 months, and started it every other day, and it STILL had the carbs mess up on it because I didn't allow the bike to fully warm up.

Also, I second adding a fuel stabilizer any time you leave the bike for more than 10 days, honestly.


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