hard rattle on cold start

[crazycanuck]

Hi all, tried searching the interwebs for answers to this but can't get the query right. I'm sure this isn't a new question, so apologizes for asking again. This is my first Yamaha and my second year of sledding, so still ramping up in general.

When I cold-start my Apex 2008 40th below about -15C, I get a hard 'rattle' coming from the 'top' of the engine. I can't tell if something is actually rattling or if it is the engine itself. It is loud. Lasts ~15s and then goes away. If it is warmer, no rattle at all.

Should I just leave it or is there something to check? Sled is in getting a new battery (also a cold start issue), yamahaheater installed, and studded. So easy to ask the mechanic to check it out.

Also, ty4 this most excellent source of info. See what I did there? So much knowledge accumulated here.

 

[72Gran]

It is normal, you should here it at -39, sounds like a diesel. Yes you need a good battery for very cold starts.

 

[maim]

normal. takes time for oil to get up there at lower temps.