PTO Spark plug backing out

CO 2.0

Well-known member

Lifetime Membership

Nov 26, 2007

4,470

2,994

113

44

Fort Collins, CO

• Dec 10, 2017

• #1

Im getting detonation at full throttle on my silber setup. I run 5lbs at 10k ft with non eth and 3 gal 104oct. New plugs and still only pto side backing out. Not getting a DET light. Any ideas what it could be? Only thing I can think of is a failing o-ring in the head letting coolant in and making the pto side detonate. Plug isnt white, its normal color. It does it more when engine is hot running for awhile, less when just starting out after resting for a bit

 

Indy_500

Well-known member

Lifetime Membership

Jul 8, 2011

1,054

465

83

29

Greenville, WI

• Dec 10, 2017

• #2

Carbon buildup possibly? Thing use a lot of oil? My 16s a pig

 

K

kiliki

Well-known member

Lifetime Membership

Dec 27, 2008

13,215

2,405

113

Nampa, Idaho

• Dec 10, 2017

• #3

move up 2 more gal of 104 and see if it stops.

 

S

SRXSRULE

Well-known member

Lifetime Membership

Aug 25, 2002

2,512

1,592

113

• Dec 10, 2017

• #4

What octane is the pump gas your mixing with? Also do you have a boost gauge to confirm the actual pressure?

 

S

sumtinwong

Free Member

Oct 4, 2016

695

209

43

north pole alaska

• Dec 10, 2017

• #5

run a 50% mix of LL ave gas see if it stops coming out. I run 5 pounds sea-level to 6000ft 50-50 mix and no problems. 25% of 104oct. might just be a little light especially if the pump gas is not fresh.

 

S

sledhead9825

Well-known member

Lifetime Membership

Nov 4, 2013

1,195

416

83

• Dec 10, 2017

• #6

I had these symptoms on Boosted Pro. Turned out to be the fuel pump.

 

CO 2.0

Well-known member

Lifetime Membership

Nov 26, 2007

4,470

2,994

113

44

Fort Collins, CO

• Dec 10, 2017

• #7

My wastegate spring cap was loose. The diaphram was a little kinked and not sealed right too. I reworked it and ran it for a couple miles today. All seemed good. Hopefully that was it. My plugs were the right color and no detonation light ever so I was thinking it should have been something other than octane level. Especially when running 91 non eth with 3 gal of 104 unleaded on 5lbs at 10k

 

R

revrider07

Well-known member

Lifetime Membership

Feb 17, 2008

2,034

1,001

113

ND

• Dec 10, 2017

• #8

Make sure the waste gate is not sticking had that happen last year.

 

AKFULLTHROTTLE

Well-known member

Lifetime Membership

Dec 20, 2009

1,987

1,146

113

Alaska

• Dec 11, 2017

• #9

Gap your plugs to a tight .020

 

P

pinko

Well-known member

Premium Member

Dec 25, 2007

693

123

43

38

Wembley, AB

• Dec 11, 2017

• #10

AKFULLTHROTTLE said:

Gap your plugs to a tight .020

Click to expand...

This recommended for turbos in general?

 

AKFULLTHROTTLE

Well-known member

Lifetime Membership

Dec 20, 2009

1,987

1,146

113

Alaska

• Dec 11, 2017

• #11

pinko said:

This recommended for turbos in general?

Click to expand...

Yes

 

J

JJ_0909

ACCOUNT CLOSED

Nov 16, 2009

1,023

1,033

113

• Dec 11, 2017

• #12

I've seen this problem a handful of times. It is either the result of over boosting (throw a boost gauge on to verify), a fuel delivery related fuel problem - IE clogged injector, bad fuel pump, fuel tank not venting properly or the EGT is acting up (there is a reason Polaris changed this entirely for 18)

Considering the octane and altitude, I'm betting on EGT, fuel pump or injectors.

Edit: Considering its happening only on one side, I'm betting injector

 

Last edited: Dec 11, 2017

HECKS

Well-known member

Lifetime Membership

Dec 21, 2007

422

250

63

Sylvan Lake, AB

• Dec 11, 2017

• #13

I would bump up your fuel ratio.
If your running 25% C104 with 75% 91 Premium
That equals 94.25 Octane.
If you were to run 50/50 that should give you 97.5
or straight avgas will be a minimum of 100.

I've been through many a plug blowing out of the head while climbing, makes it fun to turn out on 1 cylinder !