MR1 engine not running more than 6,000 RPM at times

[Konnie]

very likely my dead man/lanyard switch rolled Tango Uniform when i did the engine swap... had to replace and all was well..

To be sure I’m trying to verify what the correct values and tolerance is for the TPS but can’t find the correct values. If it is 0.747V +- 0.016V then the idle voltage is out of range on the engine that won’t start. .747V + .016 = .763V < .796 (bad engine idle voltage).
Do you happen to know the correct source for the values? I can’t find it in the service manual.

 

[84rzv500r]

manual says TPS is 0.756 +- 0.016 so 0.740 to 0.772 at 1650 RPM...

 

[84rzv500r]

PS the Waverunner service manual is WAY better than the Boat one for engine stuff...

 

[Konnie]

manual says TPS is 0.756 +- 0.016 so 0.740 to 0.772 at 1650 RPM...

So my port side is out of range by .024V.
Do think that is preventing the engine from getting a spark and signaling a “lanyard ON” status in YDS?
Truly appreciate your help!

 

[84rzv500r]

you likely have 2 distinct problems.. lanyard is a seperate issue... that has to be fixed... the 0.024 volts out of range may or may not keep the ECU from firing however. fix the lanyard wiring... try to start... then adjust the TPS and you should be good.

 

[Beachbummer]

Bypass the rear hatch and lanyard switch until YDS says you are OK.

Deadman switch you can unplug to bypass. Rear, I THINK, brown to brown and separate white to black. Look for older post from me, the diagram had been previously posted.

The switches can fail in all positions. Rear hatch has 2 separate circuits within it. One to kill ignition, the other to stop cranking.

 

[Konnie]

I disconnected one of the two connections directly under the lanyard switch and port side engine started right up.
YES! Thanks for the help!!
Before disconnecting the aforementioned connections I also disassembled the clean out hatch switch that corresponds to the port side engine. All looked good and when looking at the internals one can see how it has two circuits. One need to be closes and the other needs to be open for the engine to fire and run (allow spark and allowed to crank).

Now I need to trouble shoot how to get the lanyard switch functional again. Any suggestions and pointers would be much appreciated,
Also, I noticed that the port side tachometer isn’t working. Not sure if related to the lanyard switch issue or not.

Any pointers and or suggestions are much appreciated.

 

[buckbuck]

Lanyard switches can sometimes be repaired by simply exercising them to their limits of travel. Pull the clip and grab the switch and pull it out and back several times.

 

[Beachbummer]

With your multimeter you can fidget with it to see if it returns to operation, but there isn't much to be done in addition if it does not fix itself, you can replace it or bypass it. Best of luck!

 

[Konnie]

So replaced the kill switch with a new one. The engine that would start now starts right up.

Still have the problems that the port side engine, at times won’t rev above 6-7K.
Last weekend the over heat light came on. Turned the engine off for about 10 min. Overhear light did not come back on and engine worked fine at all RPMs.
Suspected something with the fuel pump. So switched the two fuel pumps.
Same issue, at one point the overheat light came on and port engine wouldn’t rev above 6-7K rpm.

TPS is just .024 V out of range.
Primary and secondary coil resistance are within tolerance.
Switch the ECUs and no change

Any thought?

 

[Beachbummer]

I had the same issue and compression was low on one cylinder and suspect on others. Exhaust manifold was busted and allowed water in the wrong places even though oil was fine.

I hope you have better luck. Check compression next. It's cheap to do.

 

[Konnie]

I had the same issue and compression was low on one cylinder and suspect on others. Exhaust manifold was busted and allowed water in the wrong places even though oil was fine.

I hope you have better luck. Check compression next. It's cheap to do.

In the process of ordering pressure gauge for compression test.
In your situation you describe above I struggle to understand how the busted exhaust manifold is related to low compression. Would you mind elaborate, or do I misunderstand?

 

[Beachbummer]

Mist entering combustion chamber, causing rust, leading to leaky valves. That's the theory.

 

[Konnie]

Compression tested and here are the results (PSI):
#1 157
#2 137
#3 161
#4 154

My understanding is that the compression should be at least 150 PSI and no delata should be bigger than 15 PSI.
Any thoughts and ideas are appreciated.

 

[Babin Farms]

Compression tested and here are the results (PSI):
#1 157
#2 137
#3 161
#4 154

My understanding is that the compression should be at least 150 PSI and no delata should be bigger than 15 PSI.
Any thoughts and ideas are appreciated.

#2 seems low. I would check compression on all 4 cylinders multiple times to just verify the findings

 

[Konnie]

#2 seems low. I would check compression on all 4 cylinders multiple times to just verify the findings

Did check #2 twice and got the same reading both times.

 

[tdonoughue]

I've seen worse... But yes, #2 seems low. I see at least a top-end valve job or rebuild in your future. That said, it is not as low as I would expect for a significant problem yet.

Did you get the TPS adjusted? Seems like a little, but that is almost 2x out of the spec range...

 

[Konnie]

I've seen worse... But yes, #2 seems low. I see at least a top-end valve job or rebuild in your future. That said, it is not as low as I would expect for a significant problem yet.

Did you get the TPS adjusted? Seems like a little, but that is almost 2x out of the spec range...

Haven’t adjusted the TPS. But could that really be the reason why the rpm drops down to 6K now and then?

 

[tdonoughue]

Haven’t adjusted the TPS. But could that really be the reason why the rpm drops down to 6K now and then?

Admittedly would not be my first guess. But seems like a pretty easy thing to adjust and eliminate as a potential cause.

 

[Konnie]

Mist entering combustion chamber, causing rust, leading to leaky valves. That's the theory.

Do you possibly remember if your compression values were similar to these when your manifold had failed?

Compression tested and here are the results (PSI):
#1 157
#2 137
#3 161
#4 154

Also, how did you pin point / find that it was the manifold? Did you see any leak or similar?

Greatly appreciate any help / pointers.