BS 34 carburetors

New Spark plugs
New Spark plugs caps ( One which did not have 5 K either )
New Ground wire to Coil
Started OK

And Ladies and Gentlemen --> 150 Yards and stalled again + Pushing it home.

I am next gonna bypass ignition Lock power to coil and ignition box
the ones are dodgy apparently on this model.
Since it stalls on both sides not running on one side --- I am at electrical problems

Have a stock regulator on the bike i can plug in --- and an extra rectifier at home to change to and also a Boyer Blue box with coil I can try.
( Installed is red box )

Feel free to comment .. If these are known symptoms on Boyer Coil or Red Box
 
From Boyer site - instructions for XS650.........KIT00303


1655677086677.png
 
Thank you Mr Skull there is a difference in instructions
Kit .00303
Kit 00103

Jumped the Power supply to Coil and Boyer Box -- Bypassing ignition lock and kill wiring Did not help

Connected a stock regulator and on power up dim neutral light and Poff main Fuse. Gone.
out with that and in another stock regulator ..this time no Poff in fuses
Replaced the rectifier soldering and shrink wrapping
Replaced a few connectors But begun to rain not tested tonight.

I am still at electric problem ....since it stalls on both cylinders and Pri position makes no difference.

Maybe testing blue Boyer Box after this if this did not help

Not sure at this point in time if the cam allows Points installation.
I replaced it to a better looking Cam .. but took no notice about the point aspects since I was Planning use Boyer.

It appears to charge Brushes is on the short side --- And starts reasonable well
 
Boyer Coil is out of Spec 15.2 k ohm instead of 12.5--13.5 k Secondary
Primary side borderline Low 4.1 instead 4.2-- 4.6
Going for the blue Box which coil is within spec dont know about the box. yet.
 
Jan your coil is within reasonable tolerances. If you want to test the coil momentary ground and unground the black wire from the coil and see if the plug sparks.
 
Jan your coil is within reasonable tolerances. If you want to test the coil momentary ground and unground the black wire from the coil and see if the plug sparks.

Will try that
Last check kicking it -- plugs against the head . Had spark but not strong
The right plug is still White
I remember adjusting the left idling mixture richer but not the right can that be an issue ?

Think i will try the Boyer Blue Box ..then the electrics is tested
And jetting adjustments to stock ( or so ) and see if that changes things
 
Took out the plugs and put them on the cylinder head + kicking
Muuuuch .. better spark on Left side There is one on the right side also but clearly not strong very weak
Seen sparks over the year this is weak Going for Blue Boyer setup

Edit there is a marking + and - on the coil .
Booth sparks weak if switched around
 
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Boyer Blue Box installed spark looks better
Not started engine yet

Some pictures that perhaps can help someone

Holder for the Coil hacksawed off a piece of square tubing
drilled holes matching frame and coil .added 2 nuts on the bottom side as spacers to get it a little higher up


IMAG0081.jpg




Ignition box

IMAG0083.jpg


Wiring for testing Blue is Power in that forks to Coil and Ignition Box
The switch is for possibility to cut power feed that not components can withstand

The ground wires are collected in the bolt at the middle -- And one wire all the way to battery minus

I am off to try set the ignition timing and try to start see what happens perhaps test ride.


IMAG0082.jpg
 
First kick start up No stumbling .. some tests and tweaking the ignition. Not exactly there yet
Not the perfect response ..
But usable motorcycle now.
Right plug is still whiter but the left is also a little lighter
Will a idle mixture opening on the right help would prefer a little darker
And I am thinking adjusting the needle back or even one step further down more Please comment

As in --># 59
Since nothing in the electrics leaning out the needle it is already second from top
going for the top 1 slot if this seems wrong please tell

The stumbling is gone at the Moment ..coil was a bit out of spec ..but the wiring is poor. Maybe should get a new
so I am not certain.
Some ignition tweaking and settings on the carburetor perhaps it is solved .
 
Done some reading about the carburetor setup in the tech section

I Now believe I have had a Weak spark and tried to correct that via adjusting the carburetor
Setting the mixture screw left and right different to get rid of the popping in the exhaust. left side at idle
And had stumbling in the upper mid range that disappeared setting the needle in the topmost position
leaning out
( Theory is --- not actually to rich but to rich for the weak spark )
Now believing the spark is stronger ill try to set the mixture idle at 3 turns out on both sides
Setting the needle at third slot ( can be to rich but ill try that )

I now have a stock mechanical charging regulator installed that so far seems to work That I will try to keep . Having Lower Voltage drop at startup
which makes starting better
 
I Now believe I have had a Weak spark and tried to correct that via adjusting the carburetor
Never underestimate the ignitions ability to fool you into blaming the carbs.

Underskatta aldrig tändning förmåga att lura dig att skylla på kolhydraterna.
 
Moved the needle third slot from top
Stumbling predictably at 4200 rpm on acceleration.
Need to tweak the ignition a bit also slightly to late
I think I am Going down 1 step .. on main Jet have 135
 
EDIT my bad ,,2.85 can actually be right
found a link that gives. 2.75
Not going well.
Replaced the main Jet to 132.5 .
Could not start the machine + 30 C --- kicking like a fool

Coil partially shorted ---
Have sent e mail to Boyer Bransden if this means shorted Boxes also .. Red and Blue ( feel free to tell your opinion)
I Twisted the magnet with plugs on the cylinder head and had spark ( With jumped wires ) ..but weak again.
Looks as the fuel prices wont hit me this summer.





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Have not had time for a while
Blue box Boyer and coil ..loosened the rod with the magnet and turned it passed the Pickup Coil s
Plugs out and grounded
Evidently weaker spark on right side shifted wires ..and at the end the spark plugs only and then the weak spark followed the spark plug
I believe those plugs was new more or less.

Another spark plug and both sparks the same and better .Connected everything and now have one kick start up.
Runs good at idle and above 3000 rpm but stumbles a bit between 2000 --3000
Dont think I have time to do it for a while but feel free to comment.
Stock regulator at the moment .not exactly sure what it charges needs to do another connector and connect the Voltmeter
 
Turned in the Mixture screw 1/3 turn ( From 3 i believe ) appeared to have helped 2 - 3000 range
100 km ride last night .Fine weather
Been out three nights this week fine warm weather ..

Had stumbling again some times also around 4000 rpm
Put my finger on the ignition key while riding Immediately Shot in the exhaust loud bang
So I have ordered a New Ignition Lock. Not sure if is a problem there .But It is worn and I have been in there trying to service it
Sometimes a new part is the way to go.

Here on the forum is mention of a blue spark as the right type .Never seen one of those
 
Waiting for the ignition lock I here at the forum read about the valve Play as a reason for stumbling.
Checked it and Yes intake Valves was slightly to tight.
Have never had anything else than 0.05 mm feeler gauge To set it with. Lately I found another set at a Flea Market.
Which had a 0.06 mm

The 0.05 went in but not the 0.06. Which is right according to Clymer Manual.
Can have been a mistake or wear 2 seasons Riding.
Adjusted it.
Will the play increase or decrease with wear ??
 
Will the play increase or decrease with wear ??
Depends...
If the valve stem/adjuster, rocker or cam wear, play will increase.
If the valve face or seat wear, play will decrease.
 
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I don't think just slightly tight valves would cause your issues. At .05mm, you were actually at the spec for some years. Yamaha changed clearances over the years, not sure why because the motor really didn't change .....

650ValveSpecs.jpg


It's become accepted practice to use .003" on the intakes and .006" on the exhausts for all years. Personally, I feel that .002" (.05mm) intake spec is a bit tight.
 
Not been at home for a Month
Tried to install the ignition lock from e -bay today

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According to the compatibility list on the site it should fit but the functionality seems reversed
In the off position the neutral light / horn / Brake light works
Turning to on it comes off but then the key is locked fixed in the lock cant take it out.

Cant flip the connector it is asymmetric .. Can be difficult to find the right lock
Is cutting wires and soldering something anyone has done or heard about
As Way forward.
 
Maybe you can just switch some of the wire locations in the plug?
 
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