Engine/turbo troubleshooting 800 etec

[06yamahaapex]

So how do you get detonation running 100% race fuel

Lower the compression or turn the boost down.

 

[X-Treme3x]

nope. Mine sounds the same as yours, literally 3 blips of the throttle and down she went. I boosted my ride and it has 9500km on it, ran perfect as a stocker. After the second ride I rebuilt it with a used jug, used piston and a head that definitely has damage. Fuel is key, my bet is the map is off. What size turbo are you using intake temps could be a cause as well at 10lbs.

mixing oil in the gas really is a bad way of doing it. Stop by the dealer and get the stock system cranked up, they can do this in buds. 5lbs or less go 1 value, I would suggest 1 as a minimum and maybe 2. FYI lower number add more, bigger numbers remove oil. Each sled is set differently from the factory. hat is mentioned is the etec is a dry crankcase not meant to see fuel down there. This is what cause some rods failures.

I am running a boost-it on my 15xm. 1700km on the sled an 1000km with the turbo. Is it a good idea or recommended practice to have the oil pump adjusted one point to increase it for good measure? Set at 6psi

 

[06yamahaapex]

I am running a boost-it on my 15xm. 1700km on the sled an 1000km with the turbo. Is it a good idea or recommended practice to have the oil pump adjusted one point to increase it for good measure? Set at 6psi

6psi hebb? Turn the boost up

 

[X-Treme3x]

6psi hebb? Turn the boost up

The rods might not like me for so long. It gets places on that good enough as it is lol

 

[Merc63]

What race fuel are you running?

 

[X-Treme3x]

What race fuel are you running?

C111/premium @ 40/60

 

[Merc63]

Maxwell fuel?

 

[X-Treme3x]

Maxwell fuel?

Not sure what kind he uses but it’s VP111. Haven’t had any issues yet. But the idea of the extra spray is a good point if I should have the oil injection set 1 notch more.

 

[venom]

So what does the dealer do to crank up the oil consumption

 

[X-Treme3x]

So what does the dealer do to crank up the oil consumption

I believe etec needs to be plugged into the computer. It’s adjusted electronically.

 

[maxwell]

Maxwell fuel?

straight VP 111

 

[maxwell]

Lower the compression or turn the boost down.

boost down.....but i want to turn it up~! hAHA

 

[maxwell]

Deto will erode the side / edge of the piston, similar to what you have. Typically you will see the ring locating pins come out though as well, ring turns then catches the port. Once material has been removed, the edge is thinner and therefore prone to melting faster, causing scoring. Check the ring pin to see if its loose. What is the orientation of the piston in the cylinder (to the damaged area)? Were the plugs indexed properly (I think they need to be on these motors correct?)? How does the head look? Sometimes if there is a pre-existing build up of carbon it can create a hot spot that could start pre-ignition. Is the damage to the outside of the piston (i.e. against the outside cylinder wall?)

Its important to note that detonation (or pre-ignition) can be caused by too lean of a mixture - so that's possibly how you got it running race fuel and why both theories could be correct. These engines are really lean just to meet emissions, so with boost they need lots more fuel. So some sub-par fuel and maybe slightly leaner than it should be and boom. Also, what is your ignition timing like? too far advanced will give you detonation, did it get backed down for the boost? Too hot of a range of plug also, but unlikely a cause here. Overall the other cylinder looks good from what I can see, was this PTO or MAG? Often times, due to cooling flows, one cylinder is hotter than the other, since the coolant enters the cylinders evenly from the water pump but exits only on 1 side of the head. I believe its the same on these motors. What throttle position were you in the longest just before it blew (i.e. riding along a flat area at 1/2 throttle for 1-2 mins and then punched it?). What i'm getting at is it possible you were riding in a lean spot just before you opened it up?

These engines inject the fuel directly onto the piston, so risk of oiling issues are pretty low due to the fact that the ash on the piston dome will distribute the heat and protect the dome (as its supposed to). Always worth checking but so long as 1 side was getting oil (other piston looks OK), then unlikely a pump failure but check for plugged lines, loose connections etc. anyway. Mucking around in there during the turbo install, you could have bent a line too sharp etc.

They used to correct the intake imbalance with a "boost bottle". Look up the old 440 Phazers, from mid 90's, there is a bottle between the intake boots on the motor side of the carbs. I don't see this as much of an issue since the airbox is under pressure here.

Back to deto and/or lean. Doesn't really matter at this point - run fresh race 100%, and put a bunch of fuel to it on the map, and slowly back it out. As noted, you need to do some plug readings, not just rely on A/F and / or det sensor or EGTs. Definitely need to confirm no seal leaks though, should try and give it a leak down test if you can. Just some other things to think about.

melted portion was on the corner of the exhaust port. this was after wide open throttle for about 5-8 seconds. The head looks perfect. no buildup and no pitting. ill get some pics. i agree on the plug readings. just not like the old days where it was easy to check haha

 

[maxwell]

How many km on the motor?
I have seen on boosted and non boosted motor with a little higher km on them that a 10 psi difference in compression will cause detonation on 1 side, I really see it a lot on motors where the spark plugs are hard to get at and people only check the one plug and piston for wash and color. It is a pain butt but it is the best way to set your a/f mixture.
When you rebuild check or change crank seals, at very least do a leak down test,,

ahh the fun of modding!!!

interesting. motor had about 2500km on it so that is highly possible one side was down 10 psi.

 

[maxwell]

etec doesnt have any sort of detonation sensor like the polaris?

 

[MK4TDI]

etec doesnt have any sort of detonation sensor like the polaris?

There's a knock sensor right between the injectors I believe.

 

[Merc63]

Try Fuse 116. 116 octane, no lead or ethanol. It can handle lots of boost. I run it in my car 11.3:1 with 12psi

 

[ABMax24]

etec doesnt have any sort of detonation sensor like the polaris?

Not sure a DET sensor would save you anyway. On my Polaris it doesn't add enough fuel or retard timing far enough to stop detonation with the turbo. Stock it should work most of the time. There is an audible change in tone of the exhaust as the non-detonating cylinder farts and sputters, but the one detonating just keeps on going. The best way is to stop it is to see the flashing DET on the gauge and let out. The only way it will stop otherwise is if it hits full DET and limits to 6700 rpm on a Pro.

Here is mine from 2 years ago, 15 seconds at WOT, DET light turned on 5 seconds before it quit, but it didn't hit the rpm limiting stage of detonation protection so hoped I could keep going. Was trying to help out a badly stuck buddy. But I managed to get it going and rode out 70km to the truck on one cylinder while still making 7lbs of boost.

It was caused by running too lean and having a chipped pickup on the flywheel advancing the timing on the pto side cylinder.

 

[fredw]

Max.. Is this kit intercooler or not?, long pull or short when it cratered

 

[maxwell]

Yah water to air intercooler. It's a long pull but I only got half way up which would be about 5 seconds wide open throttle I would estimate