1964 5.5 Fisherman Hard Starts, Won;t Run

[JDusza]

Hi.
I'm looking at a 1964 5.5 Fisherman that historically has run like a dream, a nice quiet hum.
This year she started earlier in the season with difficulty but now she will not start at all. I have gone though the carburetor again and do not find anything obvious. Spark shows good in a spark tester but I do not know how it would do with an air gap tester. The compression in each cylinder is around 90 psi. They are basically equal. To me this seems low. I am used to seeing 120+ on 2-strokes.
At what compression value should I expect hard starting and minimal run capability?
Thanks,
J

 

[Chinewalker]

90 psi in one of those 5.5s is solid.

Spark, Fuel and Compression are needed at correct times. Your compression sounds good, you say you have spark - is the flywheel key sheared, per chance? You say you cleaned the carb - if you choke it a bit, does fuel dribble out the throat?

 

[racerone]

If flywheel key is badly sheared on a points magneto there will be no spark.

 

[JDusza]

Thank you for the response. I have not had the flywheel off for this yet. I saw the 90 psi and got spooked. I'll look at the key next.
Cheers!
J

 

[Tech Tony]

90 psi is good for that motor. does it have a fuel pump? It could need a rebuild.

 

[Chinewalker]

Could also be the lower driveshaft - it's a two piece shaft with a slip spring clutch inside it. It's supposed to slip if you tag the bottom. If the spring breaks or otherwise gets damaged, it'll expand the lower shaft to the point where it binds up the lower unit. May make the motor harder to turn over, and by extension, it may not start up due to friction in the lower unit.

 

[jimmbo]

0.020" is the gap for the points.
Have you tried spraying a bit of gas-oil into the carb and see if it fires?


In the mid 70s my dad had a 64 5 1/2. One tough little engine. It was dropped in the water, overheated to the point of the paint on the block turning brown. It was also submerged at WOT, lost all the oil in the gearcase, and like the Timex slogan, It took a licking and kept on ticking

 

[JDusza]

I think I need to look at timing just to be sure.
Then the fuel pump. Not sure when the pump was done last. Probably time.
Spaying premix doesn't fire it.
The engine is a beauty. She purrs like nothing out there today.
J