XR1800 4-Stroke MR1 Swap

[Robb235]

Soaked my injectors in Seafoam, and managed to back flush 3 of them. I couldn’t get the forth one to flow anything though. So I’m going to box these things up and send to Witch Hunter to work on them.

 

[Yamabro]

Did you cycle them with a 9volt battery, compressed air, etc?

 

[Robb235]

Did you cycle them with a 9volt battery, compressed air, etc?

Instead of using compressed air, I used a giant syringe that’s used for mixing exact doses of 2-stroke oil. After soaking the injectors, I clamped a piece of fuel hose on the tip of the syringe, and clamped the other end to the tip of the injector. Filled the syringe with Seafoam, cycled the injectors with a 9v battery, and back flushed 3 of the 4 injectors. Couldn’t ever get any Seafoam through that last injector.

 

[dabomb6608]

Instead of using compressed air, I used a giant syringe that’s used for mixing exact doses of 2-stroke oil. After soaking the injectors, I clamped a piece of fuel hose on the tip of the syringe, and clamped the other end to the tip of the injector. Filled the syringe with Seafoam, cycled the injectors with a 9v battery, and back flushed 3 of the 4 injectors. Couldn’t ever get any Seafoam through that last injector.

Probably not enough pressure to break free whatever is in there. Not a terrible idea to send them off for a professional cleaning. Might as well send off the other skis injectors too while you are at it.

 

[biffdotorg]

Following, good luck with this project. Lot's of 2-smoke owners following, or will be finding this thread for sure.

 

[JOAN ROJAS]

just following bcus I think this is an awesome build. good luck sorting the injector issue out

 

[UnorthodoxCreations]

Can you swap injectors from one engine to the other just to confirm that is the problem? Sounds like it is but would be nice to confirm that way if it's not too much trouble to swap them.

 

[Robb235]

Can you swap injectors from one engine to the other just to confirm that is the problem? Sounds like it is but would be nice to confirm that way if it's not too much trouble to swap them.

Yeah, I’ll do that. I’ll just put the airbox and throttle body assembly from Engine #1 onto Engine #2. It won’t be tonight though, as severe thunderstorms are rolling through the southeast. If I get a chance to do it tomorrow night I’ll do it.

Unfortunately my go-to injector cleaner, Witch Hunter, is backlogged and not accepting anyone’s injectors at this time. Anyone got another injector cleaning service they recommend?

 

[UnorthodoxCreations]

Yeah, I’ll do that. I’ll just put the airbox and throttle body assembly from Engine #1 onto Engine #2. It won’t be tonight though, as severe thunderstorms are rolling through the southeast. If I get a chance to do it tomorrow night I’ll do it.

Unfortunately my go-to injector cleaner, Witch Hunter, is backlogged and not accepting anyone’s injectors at this time. Anyone got another injector cleaning service they recommend?

I don't know what cleaning costs but I'd be tempted to just pick up a set of new or used injectors versus waiting for cleaning. Doesn't sound like you really need all need injectors, maybe just one. If take a chance on a used set.

 

[dabomb6608]

I don't know what cleaning costs but I'd be tempted to just pick up a set of new or used injectors versus waiting for cleaning. Doesn't sound like you really need all need injectors, maybe just one. If take a chance on a used set.

From my experience injector cleaning is fairly inexpensive and depending on who is doing it the turnaround time shouldn't be more than a week maybe two including shipping. One of these days I am going to invest in one of those injector cleaning/testing rigs...

 

[Robb235]

Engine #2 lives

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[Robb235]

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[Robb235]

This is AWESOME!!
I was having the same issue when I did my dash rebuild on my AR230. After doing some research, I know the sensors are wired to the ECU (because it monitors the RPMs to check for low oil pressure, before activating the warning light) and the ECU puts out a negative signal for each of the 3 warning lights. I hope this helps a little.

You are correct. Grounding out the pins for the three warning lights caused them to illuminate.

 

[dabomb6608]

Just thinking here without going back and rereading all of your posts about it...

Could the engine harness and ECU from the skis be slightly different from the boat setup? I'm thinking it wouldn't take too much (if the jetski harness has any unused ECU pins) for Yamaha to program the software/ECU to provide ground to those pinouts used only by the boats. I'm sure the harnesses are for sure different anyways given lengths and ECU mounting locations but if the pinouts to the ECU are any different that could explain what is going on with the gauge setup.

I feel your pain on the wiring side of things...converted both my Trans Am and K10 Jimmy to fuel injection with a stand alone harness I built for each. I hate wiring...

 

[Robb235]

I tend to think that the ECU programming is probably very similar between the boats and the wave runners. For example, there’s a blanked off 2-pin connector that puts out the tachometer signal for the boat tachs, but it’s simply blanked off on the jetski harness.

There are three other blanked off connectors on the jetski harness, that I have no clue what they’re for. There’s a 10-pin connector with 8 black/orange wires, a 6-pin connector with 6 black/orange wires, and an 8-pin connector with 7 black wires. What the heck are these used for? I wish I had access to an AR or SX230 HO so that I could look at the boat wiring harness.

I’m wondering if one of those blanked off connectors perhaps provides the ground signals to the warning lights from the ECU? Unfortunately I’m not enough of an electrical wizard to know.

 

[dabomb6608]

Do you have this?

I see those blanked off connectors. The two pin connector for tach isn't blanked off on this diagram (green & black/orange wires)

There's a very good chance those black/orange and black wires are all just grounds. Why they would have them bundled like that is unknown unless those plugs/blanks are being used as a bus jumper to link them all together. I've seen that before.


EDIT:

Actually if you look close at those plugs in the diagram they show a line linking the top and bottom rows together. It also has all the circles for the individual wires actually touching even though all the other connectors show a small space between the individual wires in each connector...I bet those are all just junction locations for those wires. Fairly common to have junctions like that in engine/body harnesses.

 

[Robb235]

Do you have this?

I see those blanked off connectors. The two pin connector for tach isn't blanked off on this diagram (green & black/orange wires)

There's a very good chance those black/orange and black wires are all just grounds. Why they would have them bundled like that is unknown unless those plugs/blanks are being used as a bus jumper to link them all together. I've seen that before.


EDIT:

Actually if you look close at those plugs in the diagram they show a line linking the top and bottom rows together. It also has all the circles for the individual wires actually touching even though all the other connectors show a small space between the individual wires in each connector...I bet those are all just junction locations for those wires. Fairly common to have junctions like that in engine/body harnesses.

Yeah, I've got something similar. My FXHO manual also shows that green & black/orange connector as going "To Tachometer". But in real life, there is no analog tachometer and it's blanked off in the harness.

 

[dabomb6608]

Gotcha

So looking at a boat diagram, which is terrible quality compared to the ski diagram, I see the gauges have 3 separate wires as I think you've previously mentioned. Included in the 8pin connector for the gauges. Purple(oil pressure), green (overheat) and blue (check eng). The diagram simply states "to harness" for this connector. But I can't for the life of me find any diagram that shows the other side of this connector and where it goes. I also do not show the oil pressure switch or the 2 overheat thermoswitches themselves as sharing a wire color with the gauge trigger wires. This leads me to believe the gauges are not directly wired to the switches themselves as most manufactures are good about color coordination in harnesses. On the jetski harness it appears that the white wire going to the multimeter is your signal wire for its warnings. Most likely a serial type signal.

At this point I am pretty convinced that the boats have a different main harness that links the ECU/Engine/Body compared to the jetski version. As well as different ECUs to handle this aspect as well as the boat not having a steering switch and maybe more differences as well. This is at least partially evident in ECU part numbers for say a 2004 FX140 (60E-8591A-11-00 ) and a 2004 AR230 (6B5-8591A-00-00). The same differences are seen in the first three digits used for the main harnesses as well.

So a remedy of sorts would be to wire the gauges purple oil pressure switch trigger into the Pink/White wire coming from the oil pressure switch. That way when it trips the light will come on and let the ecu still know as well. Same basic idea for the overheat trigger. There are two thermoswitches. One engine and one exhaust. These are wired in series to the ecu. You can wire your gauge trigger into the pink wire from either switch to then trigger the overheat lamp as well as ecu at the same time.

The downside to doing this is I don't know how to trigger the check engine lamp...you could try and wire the white multimeter signal wire on the jetski harness to this trigger and then fool the engine into throwing a code to see if it lights up. Beyond this I don't see any wires available on the jetski harness that would indicate a check engine only trigger.

 

[Robb235]

@dabomb6608, the more I look at the wiring diagrams, the more I'm starting think you are right; the jetski ECU probably just doesn't have the outputs to work the three warning lights on the tachs like the boat ECUs most likely do. I would love to be able to find a pinout of the boat ECUs, but haven't been able to find one so far like I have for the jetski ECU.

Gotcha

So looking at a boat diagram, which is terrible quality compared to the ski diagram, I see the gauges have 3 separate wires as I think you've previously mentioned. Included in the 8pin connector for the gauges. Purple(oil pressure), green (overheat) and blue (check eng). The diagram simply states "to harness" for this connector. But I can't for the life of me find any diagram that shows the other side of this connector and where it goes. I also do not show the oil pressure switch or the 2 overheat thermoswitches themselves as sharing a wire color with the gauge trigger wires. This leads me to believe the gauges are not directly wired to the switches themselves as most manufactures are good about color coordination in harnesses. On the jetski harness it appears that the white wire going to the multimeter is your signal wire for its warnings. Most likely a serial type signal.

I did locate the wiring diagram for the 2004 SR230. While it used a different variant of the MR1 motors, the tachometer wiring seems to be similar. What stood out to me was the fact that the wires do in fact change colors. The blue "check engine" light stays blue, but the green "overheat" light turns to tan/white, and the purple "low oil" light turns to blue/white. But just like the other boat manuals, it just says "to harness" after that (see my attachment).

So a remedy of sorts would be to wire the gauges purple oil pressure switch trigger into the Pink/White wire coming from the oil pressure switch. That way when it trips the light will come on and let the ecu still know as well. Same basic idea for the overheat trigger. There are two thermoswitches. One engine and one exhaust. These are wired in series to the ecu. You can wire your gauge trigger into the pink wire from either switch to then trigger the overheat lamp as well as ecu at the same time.

That might be the only option available.

The downside to doing this is I don't know how to trigger the check engine lamp...you could try and wire the white multimeter signal wire on the jetski harness to this trigger and then fool the engine into throwing a code to see if it lights up. Beyond this I don't see any wires available on the jetski harness that would indicate a check engine only trigger.

I doubt the white wire would do anything. I believe that's just a data-only connection. I'm sure there's a pin on the boat ECU that provides a ground connection when it wants to flash the "check engine" light.

 

[Robb235]

Do the engines in the jetboats have to be running in order for the boat tachometers to flash the “check engine” light? Or can the “check engine” light flash with engines off, but key on?