can I use this oil?
Jul 19, 2000 | 08:24 PM
#12
Pro Rider
Joined: Jul 2000
Posts: 458
Likes: 0
Noticed you mentioned Castrol in your post. I began using Castrol way back in the early 80's until I developed a slight valve problem with my '85 model Toyota pickup. A valve or two would sometimes stick when the engine was first started and sound like they were going to knock holes in the top of the pistons. I happened to mention it to a friend who said that he was told that Castrol was known for leaving a buildup of varnish. While I have no direct evidence of his statement being true, I do know that the problem went away after first running a can of Rislone for a month or two before changing to Valvoline. I owned that truck for many years after that and never saw the problem again.
Jul 20, 2000 | 12:23 AM
#13
Trailblazer
Joined: Dec 1999
Posts: 38
Likes: 1
I purchased a new 2000 Polaris 425 Xpedition atv in December of 1999. Polaris puts 0W-40 synthetic oil in their new machines from the factory. The 425 holds 5.5 quarts of oil and yes it also has a wet clutch and 5 speed transmision.
If Polaris is using a fully synthetic oil for break in and recommends this for ever after, I would not be afraid to use it in any atv. Synthetic oil should even provide better protection in an air cooled engine as it will provide better protection from thermal breakdown. Most air cooled engines will run cylinder head temps of 350-400 degrees F. , while a liquid cooled head won't see much over 250 F.
2000 Xpedition 425
1994 Kaw. Mojave
If Polaris is using a fully synthetic oil for break in and recommends this for ever after, I would not be afraid to use it in any atv. Synthetic oil should even provide better protection in an air cooled engine as it will provide better protection from thermal breakdown. Most air cooled engines will run cylinder head temps of 350-400 degrees F. , while a liquid cooled head won't see much over 250 F.
2000 Xpedition 425
1994 Kaw. Mojave
Jul 23, 2000 | 12:17 PM
#14
Pro Rider
Joined: Jul 2000
Posts: 458
Likes: 0
Here is the logic behind the reason why you shouldn't use synthetic oil during the break-in period.
First of all, you cannot produce an engine with internal parts that have perfectly round and smooth surfaces. It is during the break-in period that the imperfections are worn away in a process known by many as "bedding". For example, rod bearings must "bed" onto the crankshaft during the break-in period as do many other rotational surfaces within the engine.
The problem is that synthetic oil has such excellent lubricating properties that metal surfaces will often wear into a "polished" state before bedding can occur. The end result are various surfaces that do not match more perfectly in shape and form for the life of the engine.
First of all, you cannot produce an engine with internal parts that have perfectly round and smooth surfaces. It is during the break-in period that the imperfections are worn away in a process known by many as "bedding". For example, rod bearings must "bed" onto the crankshaft during the break-in period as do many other rotational surfaces within the engine.
The problem is that synthetic oil has such excellent lubricating properties that metal surfaces will often wear into a "polished" state before bedding can occur. The end result are various surfaces that do not match more perfectly in shape and form for the life of the engine.
