76 Yamaha 650 spilling fuel?

Any idea where I can find information on checking the carbs and setting the
timing on the bike etc. or is it time to take it to my mechanic?
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

Chances are that there's at least 2 problems that need to be addressed:

(a) Petcock (is yours vacuum actuated?) leaking. This means a repalcement
diaphragm kit for teh petcock. Easy to do on your own (or you can get a
new petcock wth on/off/reserve positions)

(b) Carb floats(s) in teh bowls are not rising when there's fuel in there
to shut off teh flow when the bowl is full.

Hitachi or Mikuni carbs? Never mind - really doesn't matter (though -
if you have overflow hoses - it's probably Mikuni's)... Either way - you
can check/fix - maybe while still mounted on the bike... perhaps will need
to pull them - but the floats may be stuck.. or maybe a piece of debris in
the closing/fill mechanism letting it leak...

Another thing to watch for now, is for fuel in the crankcase. If the carbs
overflowed, and one fo teh cylinters happened to be sitting with an intake
valve open, then you've most likely got gasoline in the crankcase oil.
Open the oil-fill cap, and smell the crankcase. Iffin' it smells like
gasoline - I'd definitely change the oil & oil filter once you have the
problem(s) fixed. Gas in the oil will take away the lubricating properties
of the oil, and *can* lock up an engine.

Easy enough stuff for most bike owners who like to tinker... or most any
shade-tree mechanic. I've done this work on several bikes, and wouldn't
hesitate to do it again.

G'Luck!
Rex S.
'82 XJ650 Maxim
'82 XJ750 Seca (Project)


"HotRdd" <NoSpam.TakeThisOut@YourEmail.com> wrote in
news:1312iivgusbsk92@corp.supernews.com:

> I finally thought it might be time to pull the old Yamaha 650 out of
> the garage and see if I can get it ready for summer. I had the motor
> re-built a couple of years ago and then never finished the project. I
> pulled the bike out, charged the battery and fired the thing right up,
> no big problems except with the petcocks open the fuel is spilling out
> of the carbs/hoses. What's the deal? What can I do to stop the carbs
> from dumping fuel all over the floor when the petcocks are open?
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

It looks like the carbs. have sealed themselves again after letting the fuel
sit for a while. Now the starter seems to be jammed. Any ideas whatrwould
cause the starter to jam?


"HotRdd" <NoSpam RemoveThis @YourEmail.com> wrote in message
news:1312iivgusbsk92@corp.supernews.com...
>I finally thought it might be time to pull the old Yamaha 650 out of the
>garage and see if I can get it ready for summer. I had the motor re-built a
>couple of years ago and then never finished the project. I pulled the bike
>out, charged the battery and fired the thing right up, no big problems
>except with the petcocks open the fuel is spilling out of the carbs/hoses.
>What's the deal? What can I do to stop the carbs from dumping fuel all over
>the floor when the petcocks are open?
>
>
>
>
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

HotRdd wrote:
>It looks like the carbs. have sealed themselves again after letting the fuel
>sit for a while. Now the starter seems to be jammed. Any ideas whatrwould
>cause the starter to jam?
>

If you indavertently got excess fuel into a cylinder, that could cause a
hydraulic lock. When you hit the starter, the piston tries to compress the
uncompressable fluid and stops. If your starter is strong enough, or if you
try to start it enough times, you could bend a rod. Pull the plugs out and
see if the starter works again.

John

--
Message posted via MotorcycleKB.com
http://www.motorcyclekb.com/Uwe/Forums.aspx/yamaha/200704/1
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

This message is not archived
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

Thanks for the help guys, great advice. I'm also going to have a look at the
bendix gear tonight and see if it's warn.


<someone RemoveThis @some.domain> wrote in message
news:zJXSh.266002$lD4.4054@fe02.news.easynews.com...
> In article <7084cd895e636@uwe>, "flynrider via MotorcycleKB.com"
> <u32749@uwe> wrote:
>
>>
>>HotRdd wrote:
>>>It looks like the carbs. have sealed themselves again after letting the
>>>fuel
>>>sit for a while. Now the starter seems to be jammed. Any ideas whatrwould
>>>cause the starter to jam?
>>>
>>
>> If you indavertently got excess fuel into a cylinder, that could cause a
>>hydraulic lock. When you hit the starter, the piston tries to compress
>>the
>>uncompressable fluid and stops. If your starter is strong enough, or if
>>you
>>try to start it enough times, you could bend a rod. Pull the plugs out
>>and
>>see if the starter works again.
>>
>>John
>>
> i would put the bike on the center stand and see if it will
> kick start. if it runs, warm it up and go through the gears
> carefully. keep that rear wheel up!
> shut it off and then hit the switch. if it was stuck from
> sitting, you may loosen it up.
> you can also, with the engine OFF, put it in gear off the
> stand and rock it gently.
> many things can jame the starter, for exact help, go to one
> of the many yahoo or google 650 yamay twin groups. lots of
> really expert people and you won't waste your time on tests
> that aren't really model specific.
> then come back and share, ok?
 >> Stay informed about: 76 Yamaha 650 spilling fuel? 

This message is not archived
 >> Stay informed about: 76 Yamaha 650 spilling fuel?