yamaha air cooled 5hp. 5bs 661 non starter - crank seals?

[dieseldod]

hi lads, above motor has GOOD spark /compression /timing/fuel delivery. i,m near sure its the crank seals. even putting petrol into bore it wont fire. where would i get new seals ? any chance of a manual for this old critter?

 

[racerone]

Well it should fire with fuel in the bore.----Crank seals are not involved in 2 stroke compression.----I say you have weak spark.----Does spark jump a gap of 1/4" ( 6 mm ) or more ?

 

[dieseldod]

thanks for reply ,yes thats the bit thats got me, i checked the woodruff key yesterday , good fat spark far superior to modern efforts at spark

 

[dieseldod]

big fat and blue , i havent tested it out to 6mm only 3 that should suffice

 

[dieseldod]

ive tried different points gap settings between 12-20 thou still the same wonder what the right gap is meant to be?

 

[racerone]

I think you have weak spark.

 

[dieseldod]

new seals in, runs like a champ. thanks for the info