M7 turbo enging failure pto side

[Snostruck]

I could use some help.....
06 m7 bd race gas kit w/ pl box. it has Shain Stangers fuel system i was told form the seller.

well I took it out today, had the boost all the way down, went through my box #s, af ratio was at 10-12-13 range. strait 118 oct fuel, Sled pulled like hell up to about 1/2 throttle, then fell on its face. i noticed the PTO cylinder was about 200 degrees hotter, shut it down and that was it. I tore the engine down and found severe det.

Idk what caused it. Could i have caused that much detonation in a 15 sec pull? It almost looked like the det was post me owning the sled and i just finished it; however, the culprit is still unfound. The cylinder looked dry dry dry, plug was dry. Could my secondary injectors not be working? Bad injector maybe. Any advise would help. I just want to find a reason before i take it out again.

 

[Snostruck]

Pto side egt was 1325 at 1/2 throttle when I noticed

 

[Snostruck]

I might be an idiot. I just realied that the fuel has been all summer. Could it have lost octane?

 

[TurboM700]

Yes Never use race fuel that has been sitting for more then a few months tops. It not worth the few bucks it cost to get new fuel.

That old fuel just cost you 200-400 bucks depending on how bad it is.

Take some pics of your set up. It will be helpfully in figuring out what set up you have.

Yes you can do some major pistion damage with in 15sec you can do it in 5 sec.

Does this setup have a PL box or Boondocker box?

The big thing when learn turbo set up and tuning is to start rich crank you number or lights most the way up. Take a pull on a hill make watch your A/F or egt and make adjustments.

Change one thing at a time and one value at a time. Keep working down till you get everything in control. This can and will take you up to an hour your first time. Trust me its time well spent.

Another thing with the M7 cruising down the trail the love to get warm on the EGTS. This is hard to tune out and still not give you a bog other places. You will have to feather the throttle going down the trail. FYI

Mike

 

[Snostruck]

originally it was a boondocker pump gas, now it has a pure logic box and is race gas. i kept a very close eye on a/f ratio i never saw it go past 14 max then i added fuel for that specific range. what bothered me is the difference in egt. clearly one cylinder is getting more fuel than the other. perhaps you could give me some bas numbers to start out and most confusing is the rpm switch point.
here are some pics of the set up

 

[Snostruck]

heres a pic of the piston damage, seems extensive. i would only assume if my box numbers were to low both would be damaged. Another thing i noticed is the fuel system is kinda weird. the sled hiccups at idle. i think cuz the fuel pressure dosent stay high enough at idle. and shouldn't my pressure stay there after a couple pulls or after shutting it down. i get nothing, the needle barley jumps.

 

[Snostruck]

If it was from bad fuel wouldn't both show similar signs. Thanks for the help guys. We don't really have any turbo gurus up here in Alaska

 

[jensen]

M7

Check the boot on that side I have heard of and seen a couple that will rip and then suck air. The tears are hard to see sometimes because it will rip right underneath the metal clamp so take the clamp off and check.

 

[TurboM700]

Wow you did a good job on that piston.

It looks like Deto for sure on the piston. Bet the ring glands right out of there then caught a ring on a port and snapped it off and it bounced around on the piston. That’s what all the dent on the piston and I would assume the head are from.

How much boost where you running?

14.0 AFR would do that to a 2 stroke in a hurry.

Talk to Shain Stanger (product tester) on here I know there is a way to check those secondary injectors if they are working or not. Just can’t remember it.

Also why you have it apart you might want to think about moving the secondary injectors to the other side of the throttle body’s. This helps keep the each cylinder more consistent.

Also I have said this a million times on this fourm. The M7 does not have enough power to run
Secondary Injectors
AFR gauge
EGT gauge
Secondary Fuel pump

Heck I couldn’t even run a secondary fuel pump on mine and keep the stator in it.

This is one thing I fought for a long time with my M7. After trying everything possible to run all the above I went back to single injector’s stock fuel pump with a 2:1 rising rate regulator with EGT gauge. I got my self a pull and go turbo sled that I wanted. Trust me on this ask any one that has spend some time with the TM7 and they all will say the same thing.

As for starting number start rich and start turn them down each pull. The Switch point is at what boost level the extra injectors come in at. This I would start low I think like 3 lights if I remember. This also helps on the trail ride in keeping the egts lows.

I hope this helps

Mike

 

[Snostruck]

I had the boost all the way down, and it was hitting about 10lbs.

 

[Snostruck]

Can I just set it not to use the secondaries, or would I still need to change the intank pump and wastgate. I heard race gase set up is where the power is. I guess I'm just a little discouraged. I just got all the parts to put her back together.
I think my fuel was bad, secondaries were not set low enough(my fault) they were #6 or7 :, and boost was around 10lbs around sea level, however the boost was still all the way down. That must be as low as it goes!
What's the lowest boost you typlicaly see on a rg set up. Thanks!!

 

[bigbull]

You have a ton of variables that could of caused detonation like that. My guess is that you were runnin too lean, but the reason can be multiple things. Also, you can test the secondary injectors, but since you dont have the Boondocker box on anymore, it is not the same test. The BD box made it easy, there was a plug on the harness that could go to a nitrous type button. You could just jump that with a single piece of wire and it kicked in the injectors and it would flood the idle out.

Going back to the problem at hand, one thing at a time; the idle flubber can be caused by the same thing as the detonation. Make sure and check the piggyback connection on the Attitude box's injector connector and make sure they are solid and not corroded. Then chec your fuel pressure at idle (44lbs.) and at WOT, that single pump system requires a 2:1 rising rate regulator and that regulator has to be dialed in properly. A faulty or unadjusted regulator could cause this, a faulty Attitude box could burn it down. My buddy had a bad box and burned it down twice before he figured it out. Programming could be screwed up due to moisture or a bad ground, or electronics screwed up.

Also, the fuel pump requires a battery to run when you start it (if this is ProductTester's M7 fix it kit), if the battery is failing or not fully charged, this can cause fuel pressure issues. Pipe, head leaks can cause detonation under high boost. You seem to have the heavy spring for the boost controller installed. Do you have the light spring for 10lbs and under? I would definitely turn it down to troubleshoot. Get the spring from turbosmart if you dont have it already.

My recommendations are like TurboM700 says, you want a pull and go M7 turbo? Make it a 2 injector, single stock fuel pump, system with an attitude box (programmed for that) or a BD box with ADA (even better for tuning IMO) You can still turn up the boost to 9-10 pounds on race fuel and be much more dependable. Best of luck and hope you get it dialed in.
BB

 

[Snostruck]

Thanks BB. I have alot to go over befor I run it.
I want a pull and go sled, I'm getting the idea this isn't it. Would running the fuel system of a batterie charged by what normally powers the pump work. Might avoid the blubber at idle and lean spot from low voltage.

Then again I do want to pull and go. Do I just need a stock fuel pump?

 

[Offroad Engineering]

Then again I do want to pull and go. Do I just need a stock fuel pump?

No, you need a stock sled Horsepower requires knowledge and if you aren't willing to take the time to learn how everything works and how to tune it you need a strong factory sled.

 

[Snostruck]

Thanks offroad E...... Who wants to buy a tm7.


Now really... Would I be better of with a batt system or down grade the fuel system?

 

[TurboM700]

Dont give up

Thanks offroad E...... Who wants to buy a tm7.


Now really... Would I be better of with a batt system or down grade the fuel system?

Dont give up you will get it figured out there is plenty of people on this fourm alone that will help you. It a learn lesson I went thru this same thing back in 2006 learn from my mistake and headache.

I would down grade your fuel system here is why.

If you are trying to run all these electronics thru a battery what going to charge the battery?

The stator will "try" and charge the battery but it doesnt have enought power and it will be runing at full output and it will burn up.

Alot of people run a big capictor in the system. Looks like a blue pop bottle you may have one.

This is like a battery and helps out but it still not enough. If you want a pull and go sled go back to a stock fuel system.

I'm working on a few different system for the M sleds that are full mechaincal fuel and oil pump built into one little compact unit it still needs some more testing but if it all goes as well and if work ever slows down I might get around to selling them.

Mike

 

[product tester]

there is alot of good info on here If you want to make the thing right there is a check list of what you need to check call me and we can figgure it out with out spending more money for boxs or pumps. first check the carb boots very well on the side that burned down, you dont need a battery!!
it looks like you have a holly regulator witch is a 2 to 1 this will work, but if you loosing pressure at an idle there is a problem with something.
call me we can go over it on the phone. 801 6686344 shain

 

[Boyko]

How many miles have those pistons seen, what kind of boost did the other owner turn it up to. I could not see any specking on the top of the piston.

 

[Snostruck]

Thanks turboM700 and producttester .More than helpful. It's like a shop in your pocket. I am going through the sled today. I am going to try a few more times (at least if I have to) to run a race gas set up. I'll keep posting what i find. Do I need to doubble stack clynder base gaskets or modify my head. I ride 0-6500?

Product tester I'll most likley be calling you and again thanks guys.

 

[Snostruck]

I found a crack about 1 inch long on the reed boot. I hope this was it. I'll be putting it back toghther this weekend.

Does anyone know how to test the secondaries on a pure logic box? Also should my fuel pressure be a little below 44 at idle. Then jump to 44 after it's reved up a Lil bit. This sled looses all fuel pressure as soon as you shut it of. Pulling on it does not build pressure. I'll check the capacitor when I get it back together, but it should hold pressure.
I cashed my turbo. I still don't think I did all this damage. I'm thinking it's the reason I got it for cheap.

I'm going to uplode a pic of the other piston. I have no idea how many miles are on them. I think it's never been open. The piston says STD. Let me know what you think of the wear.