Bogging 2012 with cardboard brown PTO side and black Mag side sparkplugs....THOUGHTS?

RexFlex23 · Jan 5, 2018

Bogging 2011 with cardboard brown PTO side and black Mag side sparkplugs....THOUGHTS?

Just got back from Cooke City.

1st day I had an occasional bog after idling but it would "clear it's throat" and run great again.

2nd day it bogged all day at any and all throttle position with intermittent check engine light but would never say on long enough to pull the code.

At times I could feather it and it would scream and then bog. Checked plugs PTO side was cardboard brown, MAG side was oily black.

Swapped EGT sensor to no avail, same with plugs.

It back fired a couple of times on me as I limped it back home. When in bog mode 6000-6500 max rpm.

If it was fuel pump I'd think both cylinders would have issues? Injector seems reasonable if one is sticking open (MAG) or an exhaust valve is not opening.

Reading other posts on the "bog" isn't reassuring with dealerships throwing parts at it...Exhaust valves cleaned 2 yrs ago (very little buildup), same with fuel filter replacement.

Total of 10 days riding on those cleaning/changes.

I use Mystik JT4 full Syn. oil, have for the past 8 years. Stabil or seafoam in tank during storage, always run 91, and oiler is turned up.

Anyone have any thoughts or things to start with? .... or if the answer is take it to a dealership do you have a recommendation for one in North Eastern Twin Cities MN, one closest to me is on the "umm last resort", side of things.

Thanks in advance!

.

SRXSRULE · Jan 5, 2018

If the check engine light came on, even briefly, you will have a code stored. That would be the first place to check, you could have your local dealer just scan the computer for you and then fix it yourself.

Most of the time the injectors dont stick open... they go open circuit electrically and dont open at all. You can be riding along steady throttle and you just loose one cylinder, then it comes right back. This can happen for seconds or minutes and is usually temperature sensitive.

I would also do a compression test on it and just make sure the basics are good. In MN I would guess you should see about 125psi on each cylinder.

peaceofwork · Jan 5, 2018

Well I,m just learning ang guessing but let me run this idea past you. Pull out your power valves and check the diaphragms fore a crack or hole, and while its apart get chase the vent holes in the pv housings and the holes through to the monoblock cylinder bores- make sure the piston on each cylinder is down before pushing the wire through. Now while the pv' are still out look through the pv openings at the Pistons and rings to confirm they are not damaged. And you might as well look for bits or balls of aluminum on the inner porcelain of your plugs and of course new spark plugs might be the first and cheapest least time consuming thing you could try.
Report back what you find I'm sure others here will help or tell you to buck up for a Indy Dan long rod motor.

peaceofwork · Jan 5, 2018

SRXSRULE said:
If the check engine light came on, even briefly, you will have a code stored. That would be the first place to check, you could have your local dealer just scan the computer for you and then fix it yourself.

Most of the time the injectors dont stick open... they go open circuit electrically and dont open at all. You can be riding along steady throttle and you just loose one cylinder, then it comes right back. This can happen for seconds or minutes and is usually temperature sensitive.

I would also do a compression test on it and just make sure the basics are good. In MN I would guess you should see about 125psi on each cylinder.

Their you go a faster answer than my ideas

XCaSSAULT · Jan 6, 2018

In my experience it’s worth the xtra 30min drive south on 65 to the dealership in fridley:face-icon-small-coo. I’d avoid the one in east bethel at all cost:face-icon-small-dis

peaceofwork · Jan 6, 2018

Could this be caused by a bad reed? I'm thinking probably a check engine light would not flash over this and a poor idle would be present?

kiliki · Jan 6, 2018

peaceofwork said:
Could this be caused by a bad reed? I'm thinking probably a check engine light would not flash over this and a poor idle would be present?

^^^
bad reed.

05rmksteve · Jan 6, 2018

Where are you located? I'm up in Brainerd and have some spare 12 pro 800 parts you could try. I've had 5 different 12s and have 2 at the moment. Does it sound like it's dropping a cylinder? When it was acting up did it idle fine? Possibly a bad seal leaning it out.

RexFlex23 · Jan 8, 2018

Idle wise sometimes it's fine, next minute it will drop to 900rpm, dash lights flicker and at times will die. if I blip the throttle at times it will settle in at 1700 ish rpm and idle just fine other times I have to constantly give it a bit of throttle to keep it running at idle. outside of the idle issue I haven't had an issue util this last trip where the MAG side was black but the PTO side was nice and brown. I can't speak to dropping a cylinder as I'm not sure what that sounds like... knock on wood my sled has been good to me thus far. ~4k on the chassis and < 800 miles on a 2012 motor. Last year I swapped out a couple sets of the reed petals because they were chipped and not sealing. I probably should have done all new oem cages, etc. but I didn't. :face-icon-small-con

RexFlex23 · Jan 8, 2018

I'm in White Bear

TRS · Jan 8, 2018

Did you check your ignition wires and caps?
I would start there.
11&12 had rub through issues with the “injector side” harness on the mag side of the fuel rail.

RexFlex23 · Jan 8, 2018

TRS said:
Did you check your ignition wires and caps?
I would start there.
11&12 had rub through issues with the “injector side” harness on the mag side of the fuel rail.

Hmm good to know, will check that out as well! Will say both plug caps were full of soot when I pulled them and swapped plugs in Cooke. Cleaned as best I could and put in new plugs but still bogged. Will check the wires for rubbing. Going to have the dealer pull the codes as well.

05rmksteve · Jan 8, 2018

Just had one of my 12s act up. It would run and idle fine then it would start to bog and foul a plug and idle low. I put new plug wires and boots on and that helped some but it would still bog and not idle properly. Check my spark and 1 plug had a little less spark than the other. Changed out the coil and it ran great till the vr started acting up. The sled would run great than just die. It did that a few times then it would start but when you would give it gas to take off the gauge would go out and the check engine light would come on then it would die. Towed it back to the truck and put a different voltage regulator and capacitor in it and it ran great again. I'm not sure if it was my vr causing the problem all along or if I did have a bad coil then a bad Vr.

RexFlex23 · Jan 11, 2018

Update...

Cold compression is 123 PTO side and 122 MAG side. Pulled Mag side exhaust valve and it was oily underneath (engine side) but clean and dry on outside. There was what seemed like water when I pulled the exhaust valve but it was clear and my coolant is green and not missing any. Pulled the sylinoid and there was same clear fluid in it. Checked the hoses and all were clear. Checked for frayed wires on rail and plug wires and all were fine. Looked at MAG side piston, rings through exhaust valve opening and all seems just fine there too. I still need to bring it in to get the codes pulled but thinking it's an injector or the MAG cylinder is crap once warm/hot. Something is odd someplace...

peaceofwork · Jan 11, 2018

If your mag side injector was quitting injecting fuel intermitantly wouldn't you then have that cylinder leaning out and melt a piston in short order?

assaulted-one · Jan 14, 2018

Sounds like the injector is sticking open.

tuneman · Jan 17, 2018

Pull the engine code yourself and report back what it is. If you don't know how to do that, just apply the parking brake, start the engine and toggle thru the displays until you reach the "Err" display and record the number. Then press and hold the mode switch to see if there are any other error codes. The service manual says the check engine light must also be illuminated, but that's not my experience.

RexFlex23 · Jan 18, 2018

Codes pulled

p0261 - mag cylinder port open circuit
p1555 - throttle releas switch signal circuit short to voltage
p1552 - stuck throttle
p0177 - fuel type circut out of range

recommendation: Injector issue(s); replace all injectors to start.

I've traced through the wires and I have not seen any rubbing through to cause a short type scenario. Plug wires and injector wires are all zip tied away from anything metal in addition. PTO side card board brown, MAG side black and wet. Pull injectors and OHM them out and get them cleaned or throw them in the trash and get new or..?

Also reported that I need to replace 4 injectors but I thought there were only 2 on this motor?

Thanks
-Matt

XCaSSAULT · Jan 18, 2018

Only two

You could have them flow tested

peaceofwork · Jan 18, 2018

Hey don't wast your time or money on the 12 injectors. I say just buy new ones because they come with a new harness. Knowing that harnesses are known trouble source scrap that crap and start with new . Suppose you have a intermitant failing injector? It could lean it out on that side? It would be crapy to loose a motor over an old 200 dollar part

Bogging 2012 with cardboard brown PTO side and black Mag side sparkplugs....THOUGHTS?

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