Engine Oil Pressure Check

aboyfromkansas · #1 (**permalink**) 07-02-2005, 07:22 PM

I recently changed the oil on a Yamaha 350 Warrior ATV. I bought the ATV used so not sure about it's prior maintenance history. The manual says that after changing the engine oil and cleaning the engine oil filter that an oil pressure check should be performed. This is done by slightly loosening the oil galley bolt in the cylinder head with the engine running at idle for no more than a minute.
Says you should see a slight seep. I'm not sure what a slight seep is suppose to look like but don't think I saw much more than maybe a little trace of oil.

Why does Yamaha require this and what could one possible do wrong changing the oil to cause a problem with the oil pressure.? The drain plug has an O-ring, strainer and spring. Seems simple enough. The oil filter pretty much the same way. Straight forward. Just slip it out clean and re-install.

Could anyone please comment on this and maybe offer some advise to a new ATV owner. The previous owner says he did the maint. and the ATV only has about 45 hours of operation.

Thanks for your help,
Bill

ridnwarrior · #2 (**permalink**) 07-02-2005, 09:31 PM

On the Warrior engine, you drain the oil and then refill it.
When you restart the engine there is air trapped in the cylinder head which needs to be let out or you will overheat the engine. You loosen the gallery bolt as described in your manual until oil starts to seep out. Naturally the more you loosen the bolt the more oil will seep or leak out. As long as you have let oil out that bolt hole you have pushed all the air out of the chamber it is trapped in.
Tighten the bolt (not too tight, it is a small bolt) and have fun cleaning the oil off the head which will now smoke until all the oil is burnt off. Then enjoy the ride.

aboyfromkansas · #3 (**permalink**) 07-03-2005, 02:52 PM

Quote:

Originally posted by ridnwarrior@Jul 2 2005, 03:31 PM
On the Warrior engine, you drain the oil and then refill it.
When you restart the engine there is air trapped in the cylinder head which needs to be let out or you will overheat the engine.* You loosen the gallery bolt as described in your manual until oil starts to seep out.* Naturally the more you loosen the bolt the more oil will seep or leak out.* As long as you have let oil out that bolt hole you have pushed all the air out of the chamber it is trapped in.
Tighten the bolt (not too tight, it is a small bolt) and have fun cleaning the oil off the head which will now smoke until all the oil is burnt off.* Then enjoy the ride.
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Thanks for your explanation. I do most of all my own maintenance on my cars, boats and now the ATV and just wanted to be sure I wasn't doing something wrong. This is really a good website and a big thanks to David too.

Regards and thanks again,
Bill