Heavy pulled engine

[Bendix]

Hi!
I have many years of experience of rebuilding snowmobile engines, change bearings on crank, new pistons and so on.
But Its my first time rebuilding a vmax 540 engine.
Today its finally first time to pull the rope.
But the engine is really hard to pull. I almoust lifting the snowmobile.
Before i mounted the both crank cases together the crank turn smothly and easy, and bearings are ok.
The bore and pistons are std.
The pistons ring gap is 0.4mm
Pistons are lubricated.
The water pump gear is right mounted, what I can see.
No strange sound of something mounted wrong.

Have anyone any idea what causes this problem?

Thanks in advance

[Bob Vehring]

I did when first finished my big bore, actually had to have my kid pull the rope for a while, now its IMO a little hard but not that bad after some running. I will say for whatever reason when really cold outside and it sits,both my SRV and my V Max are really hard to turn over. My Cat 6000 isn't much different hot or cold.

[Vmax540]

Take the plugs out and with ignition Off pull the rope very slowly to make sure the crankcase did not flood.

[Bendix]

Now, after some days of starting up the motor many times, its getting much more easyer to pull. I guess one simple reason is that just this temporary garage of mine, was realy cold this days. Below -15C and I use a diesel heater for short term heaten up. The engine was so cold...
Thanks any way for answers