I am trying to picture this in my mind.
with the 180 degree crank the 4 phases are 270 degrees out. So as an engine fires slightly before TDC the non compression/power stroke would be on inlet/compression. Not sure how this would work with a wasted spark.
Sorry to side track your thread Tunster, but you have my curiosity going.
inlet | compression | power exhaust
compression | power | exhaust inlet
New resto new member checking in
- Waveblaster
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Re: Cb72
The 180 goes BANG, BANG, EXHAUST, EXHAUST.
The 360 fires one piston each time they are at top together. .........lm
The 360 fires one piston each time they are at top together. .........lm
Tunster wrote:No prob waveblaster i dont know the answer but am interested in what others say on this. Feel free to ask more.
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Racer project
Hello Tunster,and Waveblaster
OK, I probably should have underlined probably. It does look like a Boyer system ( from "box" taped to chassis behind carbs and type of trigger )and it certainly is a dual lead coil.
We now need to know two things is it a 180 or a 360 crank and does the trigger rotor have one or two magnets on it (cant tell from the pictures but this might tell if it fires once or twice per revolution, most likely twice with one magnet ?
Regards to the battery it wont matter what one it is for checking things but the Boyers seem to need decent voltage 10v + ( I used to always have a spare changed up and change it between races but you get better batteries now )
I just saw the post from Loud Mouse so put something down the plug hole and lets see where the pistons are at least. Did you check the gears ? and what size are the carbs ? ( it will be on the side of them 28, 30 etc.)
Another strange question what size are the forks at the top section they look like they may be early ones.
Regards
Gordon
SAFOJ
OK, I probably should have underlined probably. It does look like a Boyer system ( from "box" taped to chassis behind carbs and type of trigger )and it certainly is a dual lead coil.
We now need to know two things is it a 180 or a 360 crank and does the trigger rotor have one or two magnets on it (cant tell from the pictures but this might tell if it fires once or twice per revolution, most likely twice with one magnet ?
Regards to the battery it wont matter what one it is for checking things but the Boyers seem to need decent voltage 10v + ( I used to always have a spare changed up and change it between races but you get better batteries now )
I just saw the post from Loud Mouse so put something down the plug hole and lets see where the pistons are at least. Did you check the gears ? and what size are the carbs ? ( it will be on the side of them 28, 30 etc.)
Another strange question what size are the forks at the top section they look like they may be early ones.
Regards
Gordon
SAFOJ
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- Location: KERRVILLE, TEXAS
Re: Racer project
Look at the part under the lower TC.
Is it square or slotted?. ...lm
Is it square or slotted?. ...lm
GORDON BROWN wrote:Hello Tunster,and Waveblaster
OK, I probably should have underlined probably. It does look like a Boyer system ( from "box" taped to chassis behind carbs and type of trigger )and it certainly is a dual lead coil.
We now need to know two things is it a 180 or a 360 crank and does the trigger rotor have one or two magnets on it (cant tell from the pictures but this might tell if it fires once or twice per revolution, most likely twice with one magnet ?
Regards to the battery it wont matter what one it is for checking things but the Boyers seem to need decent voltage 10v + ( I used to always have a spare changed up and change it between races but you get better batteries now )
I just saw the post from Loud Mouse so put something down the plug hole and lets see where the pistons are at least. Did you check the gears ? and what size are the carbs ? ( it will be on the side of them 28, 30 etc.)
Another strange question what size are the forks at the top section they look like they may be early ones.
Regards
Gordon
SAFOJ
- Waveblaster
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- Location: Perth Western Australia
another way maybe to inspect the points cam lobe. Example 180 degree on left 360 on right
www.flickr.com/photos/125589394@N08/15215747755/
www.flickr.com/photos/125589394@N08/15215747755/
Cb72
Just like to say thanks Phil D for the disc. That will come in handy for sure.
I removed the carbs yesterday to find they were full of crap. So much so the needles had set in the carbs. A little gt85 and the heat gun soon freed them and so now there in the parts cleaner. Will finish them tonight hopefully.



I removed the carbs yesterday to find they were full of crap. So much so the needles had set in the carbs. A little gt85 and the heat gun soon freed them and so now there in the parts cleaner. Will finish them tonight hopefully.


