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Discussion Starter #1
can the top end ( piston and rings ) be replaced with out removing the engine ?????
 

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Yes.
Just remove the front plastics and gas tank.
 
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Discussion Starter #3
smokin

well that is good news...thanks. Im assuming the rings are gone...with the engine running the pressure in the crankcase seems very high. with the dip stick removed pressure coming out the dip stick hole is high.... leak down and compression test tomorrow to verify... and tips on the top end removal are appreciated....BTW engine smokes like a chimney when accelerating and de-cell.::surprise:
Also.. when i look up the Yamaha parts list only the griz is listed...no kodiak.. i'm assuming the 2 are VERY similar and use the same engine parts for the 450 EPS ?
 

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Also.. when i look up the Yamaha parts list only the griz is listed...no kodiak.. i'm assuming the 2 are VERY similar and use the same engine parts for the 450 EPS ?
Yes, they are the same bikes.
 

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well that is good news...thanks. Im assuming the rings are gone...with the engine running the pressure in the crankcase seems very high. with the dip stick removed pressure coming out the dip stick hole is high.... leak down and compression test tomorrow to verify... and tips on the top end removal are appreciated....BTW engine smokes like a chimney when accelerating and de-cell.::surprise:
Also.. when i look up the Yamaha parts list only the griz is listed...no kodiak.. i'm assuming the 2 are VERY similar and use the same engine parts for the 450 EPS ?
Same bikes. It was Grizzly in the USA, named Kodiak in Canada.
 

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Discussion Starter #6
high crankcase pressure

just thinking outside the box here...... My 2014 kodiak 450 is smoking like a chimney...the crankcase pressure is very high.. is it possible that the crankcase vent if plugged is causing this smoking issue...compression test showed 160 psi and 180 with oil poured in the cylinder...the engine starts well and runs well.
 

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Plugged crankcase vents will blow out crankcase seals. It shouldn't cause oil burning.

You could still have a bad oil control ring. This will give you good compression but still burn oil. You could also have a cracked ring. I have seen engines with cracked rings still make full compression, but it would fail leak down test.
Or you could have leaky valve seals causing your oil burning.
 

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Discussion Starter #8
CC pressure

Plugged crankcase vents will blow out crankcase seals. It shouldn't cause oil burning.

You could still have a bad oil control ring. This will give you good compression but still burn oil. You could also have a cracked ring. I have seen engines with cracked rings still make full compression, but it would fail leak down test.
Or you could have leaky valve seals causing your oil burning.
OK fair enough... but what about the high CC pressure....and what is considered normal CC pressure ?
 

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OK fair enough... but what about the high CC pressure....and what is considered normal CC pressure ?
Why do you think you have crankcase pressure?
How are you measuring the crankcase pressure?
Are you mis-interpretating air pressure with air flow?

If the crankcase vent is open, then it will not be pressurized. You'll have air flow in it due to the piston moving and down in the cylinder (and other rotating parts causing air flow), but it can't pressurize with the vent open. Even if you have massive piston blow by, it can't pressurize with an open vent.
If you've removed, say a timing plug for instance, and then cranked it over and had airflow come out that hole....this is normal. I only use that example because I have seen people misinterpret this before. Thinking they had a problem when they did not.
 

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Discussion Starter #10
cc pressure

Well the leak down test shows leakage past the rings which would be the cause of the high CC pressure....tear down to start today
 

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Well the leak down test shows leakage past the rings which would be the cause of the high CC pressure....tear down to start today
Well done! Hopefully a fresh piston and rings is all that's needed. The leak down tester is the best way to positively detect that stuff.

Dezz didn't mean anything bad by his post. I completely understand where his coming from. Alot of people try and "Diagnos" engine issues utilizing inaccurate method of,

"When my engine is running, I feel alot of air pulsations when I removed the dip stick! My rings must be shot!"

Instead of using the proper diagnostic tool like you did.

Goodluck and post lots of pics!
 

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Discussion Starter #12
top end

Ok ..tear down complete....-
- head good. new seals and lap the valves for good measure. Exhaust port is soaked with oil..as is the spark plug.
- Bore is in spec, hone done for the new cross hatch.
- piston ..good, rings ....well LOL....ring gap as per the book is .024 max on the top one...my gaps were..well more like .070 LOL
not sure what caused that , but the rest of the top end is in great shape...what did the PO do to ware the rings this much in 180 eng hrs..:surprise:
But the good news is that a few internal parts and some gaskets and all should be back to better than new :grin2:
Parts order tomorrow.....
BTW... What do you guys set your intake and exhaust valves at ????
 

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Valve clearance (cold)
Intake
0.09-0.13 mm (0.0035-0.0051 in)
Exhaust
0.16-0.20 mm (0.0063-0.0079 in)

That's the valve adjustment limits right from the service manual. I prefer to set them in the middle to loose side.
 
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Discussion Starter #14
Valves

Valve clearance (cold)
Intake
0.09-0.13 mm (0.0035-0.0051 in)
Exhaust
0.16-0.20 mm (0.0063-0.0079 in)

That's the valve adjustment limits right from the service manual. I prefer to set them in the middle to loose side.
.

Yes on the loose side is good. My old Honda DOHC CB,s call for .001 -to .003 on the intake and exhaust but that burns valves so we set them to .006 for good measure....I think i'm going to try 5 thou on the intake and 6 thou on the exhaust...:smile2:
$300 in parts today...not bad...all OEM Yamaha stuff
 

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Yamaha engine parts are actually very well priced. In many cases being cheaper than aftermarket parts....it's everything else that they over-price into the atmosphere.
 

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Discussion Starter #16
yes good pricing....even better with 15% off with my OFTR membership
 

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Discussion Starter #17
smoki

got the 450 Kodiak eps all finished up today....runs like a charm and NO SMOKE LOL !!!...

Before i stripped it down i noticed the rad had a considerable amount of mud on it so i power washed it down...figured it would be good, but during re assembly i decided to remove it and take a closer look....there was still a lot of muck blocking the rows and fins ..all good now. I'm thinking the PO overheated the engine and cooked the rings...( no damage to the cylinder) the only other thing i could find out of spec was the exhaust valve to guide clearance,,it felt a bit loose...but i let it be and just went with new seals.And i replaced the exhaust rocker shaft ( funny ware pattern on one side) Going to load her up and hit the cottage for a good road test and seat the rings... :lala:
I think i did good on this deal..... $340 total in parts and that included a couple of body side panels , rear gear oil, plug and oil filter... besides the fact i got it for next to nothin...:grin2::grin2::grin2:
all have a great winter...
Ed
 

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Discussion Starter #18
BTW is there an empty power plug somewhere in the front to hook up hand warmers ????
 

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BTW is there an empty power plug somewhere in the front to hook up hand warmers ????
There is...
But the good warmers don't come with the Yamaha plug. They need to be spliced. The good warmers are the Heat Demons with the clamp on grips! I simply spliced mine into the red/black wires on my winch installation harness to leave the factory Yamaha wiring harness unscathed.
 

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Discussion Starter #20
aux plug

thanks..great info... but were is the spare plug located ??
 
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