225 promax failure diagnosis

**Promaxin** · 04-17-2020, 01:50 PM

Originally Posted by PanRonnie

the bulletins

thanks will have a read, interesting with the ecus. Can Simon or Brucato flash an a32 tune into the a17 box?

**Dave Strong** · 04-17-2020, 01:54 PM

A17 is a good box.

Dave

**tux974** · 04-18-2020, 05:29 AM

I agree with Dave. Having run and used many A17 boxes when they check out they are good boxes, I actually like them.
I personally check all parameters on all my own boxes.
Some of the early A17/A12 did have an issue hence the bulletin but not all.
Get yours checked would be my advice.

My guess if you had and issue with it you would have scuff multiple cylinders....JMO

Brucato can check it but does not flash them.
Simon does them, I have never used him and have heard not easy to work with.
There is a guy Dennis Hoffman that does them, look him up on FB.
$650 will be the approx going price to fix/reflash.

**Mrzip** · 04-18-2020, 09:31 AM

ECU.. Send it to Dennis Hoffman.

**Promaxin** · 04-18-2020, 08:05 PM

Originally Posted by tux974

I agree with Dave. Having run and used many A17 boxes when they check out they are good boxes, I actually like them.
I personally check all parameters on all my own boxes.
Some of the early A17/A12 did have an issue hence the bulletin but not all.
Get yours checked would be my advice.

My guess if you had and issue with it you would have scuff multiple cylinders....JMO

Brucato can check it but does not flash them.
Simon does them, I have never used him and have heard not easy to work with.
There is a guy Dennis Hoffman that does them, look him up on FB.
$650 will be the approx going price to fix/reflash.

ok good to hear the feedback from a few guys using the A17 successfully, it got me worried that they weren’t any good. I’ll have a look at some options with getting it looked at as a safe guard.

**tux974** · 04-19-2020, 05:39 AM

Originally Posted by Promaxin

ok good to hear the feedback from a few guys using the A17 successfully, it got me worried that they weren’t any good. I’ll have a look at some options with getting it looked at as a safe guard.

The issue with these boxes is that they are getting up there in age so they do go bad from time to time. I have found that when they get checked out properly (even warm them up a bit) if they check out good they have worked well me.....JMPO

**tlwjkw** · 04-19-2020, 05:41 AM

i would think by now most all tha bad ones from production have run their course...........

**Promaxin** · 04-19-2020, 08:30 PM

This motor is going on a relatively heavy hull probably around 1100-1200lbs. I want it to make as much torque as possible. So far heads have been cut to 35.5cc, I purchased some ccms reeds and stuffers but couldn’t get the stuffers to seal they protruded from the front half, so I believe it may have been milled at some point in its life. Have done some light blending in the exhaust chest, tried to remove any casting imperfections as I go. How much room is there using the factory ecu for further block work without it going lean? Was considering trying to match the ports to liners and put a chamfer on the ports as Dave mentioned some of the port windows feel sharp to me. Going to use an external Bosch pump and reg when it goes back together, is there any way of just increasing the fuel pressure a tough say 42psi to safe guard against detonation during break in, than start tuning for piston wash from there and could adjust the pressure back to 39psi.

Its only for social boating and don’t have any desire to spin it past the factory set limiter anyway.

something else I noticed was this motor has orange tipped keihin injectors. Were all the pro maxes pink tipped? Did the promax injectors flow more than the 2.5 150-200 efi motors?

**Merc 2.5** · 04-20-2020, 04:28 AM

Bout the injectors. I belive they all flow same 200 fishin or 225 pm

**tux974** · 04-20-2020, 04:57 AM

Did not want to get into what your current POSSIBLE cause was because not having the motor in front of me it would be pure speculation/guess that can probably cause more confusion. I would strongly suggest to work hard on confirming the POSSIBLE cause before you put it back together.
Your tips may look orange but I'm sure they are pink which are the correct ones, yes the 200 will flow the same rate.
As for changing to on board fuel pump put a adjustable regulator and if you plan on playing with pressure get pyro's.

**Promaxin** · 04-20-2020, 04:27 PM

Originally Posted by tux974

Did not want to get into what your current POSSIBLE cause was because not having the motor in front of me it would be pure speculation/guess that can probably cause more confusion. I would strongly suggest to work hard on confirming the POSSIBLE cause before you put it back together.
Your tips may look orange but I'm sure they are pink which are the correct ones, yes the 200 will flow the same rate.
As for changing to on board fuel pump put a adjustable regulator and if you plan on playing with pressure get pyro's.

That’s what’s scaring me with it is putting it back together and it happens again. Will just have to double check everything as it goes back together. Pyros and external pump and reg will hopefully give it some more security. Any recommendations for pyro gauges?

**tux974** · 04-21-2020, 05:17 AM

Originally Posted by Promaxin

That’s what’s scaring me with it is putting it back together and it happens again. Will just have to double check everything as it goes back together. Pyros and external pump and reg will hopefully give it some more security. Any recommendations for pyro gauges?

For me the proper starting point at this time would be a good and knowledgeable machinist to get the block and tolerances correctly. Can not build a good home without the proper foundation.....

As for gauges do a search CP Performance in CA they have a good selection.

**Promaxin** · 05-02-2020, 07:00 PM

Thanks tux, sat down with the engine builder and measured piston to bore on the damaged cylinder and was 7 thou, and another cylinder was 7.5 thou and out of round. Both these cylinders are on the same bank. Problem I have is being fresh rebuild the other bank of cylinder is all brand new sleeves and 6 thou piston to bore with nice even comp. But at the moment because the motor is already .20 oversize, my options are to rebore the damaged cylinder and try fix the out of round by going .30 on that bank, or sleeve it. I guess my question really is how far oversize can you comfortably go on a promax? Is .30 too far? Only going to be a social lake/river boat with stock ecu a17.

**Merc 2.5** · 05-03-2020, 05:41 AM

30 is the max I'd take it to , start getting thin and easier to over heat after that

**Promaxin** · 05-05-2020, 09:52 PM

Originally Posted by Merc 2.5

30 is the max I'd take it to , start getting thin and easier to over heat after that

Thanks merc i think the best option long term is just to bite the bullet and sleeve the side with the out of round and damaged cylinders. I think even if we oversized .30 the out of round hole in would still not be true.