XR1800 4-Stroke MR1 Swap

[84rzv500r]

well Im running the 20mm 12/18 solas set up from the 135's right now... I have a set of 22mm shafts and 11/20 Impros impellers when I twist off the 20mm shafts...

 

[84rzv500r]

oh and I missed the engine tray thing... I ditched that long ago... and there is no room as U say... I have maybe 4" between the top of the airbox and the hatch frame.... i bought some mesh cargo nets to replace the ones in the hatch cover.... i keep my spare throwable PFD's in the nets... I have room for a large Plano Toolbox and a couple spare qt's of oil on the stbd battery tray now and I have tons of new storage where the fuel tank used to be easily accessible under the bench seat... I keep my spare fenders in there... I lost the ski locker to the fuel bladder however i gained ~25 gallons total capacity and can still put an additional 5 gallons in each console below the dry storage bin. I carried water skis and noodles and such around in the ski locker for years and nobody ever wanted to use them... grandkid only wants to go tubing or snorkeling... or take the boat for Taco tuesday and or Pizza

 

[Robb235]

Memorial Day 2022 was overall a success. Had a couple hiccups along the way.

The first hiccup was the failure of my drivers side chair. We were in the chop, bouncing around pretty good, when suddenly I was on the floor. The casting that connects the plastic chair to the pedestal base shattered. Seemed like a freak thing. Upon removal of the seat, I noticed some screws missing. I wonder if this contributed to the failure. For the remainder of the weekend, I moved the passenger seat over to the driver side, and removed the broken seat. My 3 year old is young enough that he only wants to sit in my lap when we’re underway, and my 5 year old prefers standing next to me with both hands on the dash while she looks over the bow. Replacement casting is on order.




Last hiccup was at the very end of the weekend when we pulled up to the dock for the last time in preparation to pull the boat out of the water and go home. Went to start the boat back up to load it onto the trailer, and no start. A glance at the fuel pressure gauge indicated no fuel pressure. I couldn’t hear the pump priming when I turned the key on. In my setup, one fuel pump feeds both motors. I switched over to my auxiliary fuel pump, and it started up immediately. Curious why my fuel pump has failed again. It didn’t fail the same way the others did in the past. Previous failures the fuel pumps would audibly prime, but provide no fuel pressure. And previously, the failures were my fault, as I did not have the unused fuel properly returned to the tank. This time the fuel pump is completely non-responsive, and there’s not an obvious reason as to why it’s failed. It’s a 255lph pump from Quantum Fuel Systems, which I guess is junk.
WOT run:

 

[84rzv500r]

Great video... memories your kids will have with them always...

i had the same thing happen to my port seat base so I replaced them they were like $80 for the same thing on amazon and I got 2 Wise Baja flip up bolster seats and it made a huge difference.. I also raised my seat posts 6" as my knees were in my chin...

 

[Robb235]

My starboard engine oil level is increasing, and looks to have a very thin consistency. With the engine cold, the oil is measuring about 1/3 of the way up the dipstick. I thought water in the oil, but I extracted some of the oil and it doesn’t look like chocolate milk like I’ve seen before?

I’m also not getting oil in the air filter, as typically happens when the oil is overfilled.

 

[84rzv500r]

it would turn the color of chocolate milk if it had water in it
can you detect the smell of fuel in the oil?
ecu/stuck fuel injector?
TPS at high end of range?
fuel leak inside airbox?

 

[scokill]

My starboard engine oil level is increasing, and looks to have a very thin consistency. With the engine cold, the oil is measuring about 1/3 of the way up the dipstick. I thought water in the oil, but I extracted some of the oil and it doesn’t look like chocolate milk like I’ve seen before?

I’m also not getting oil in the air filter, as typically happens when the oil is overfilled.

View attachment 182285

Bad ecu is common causing injector to stay open filling crankcase with gas. Lots of posts on this. Gets wet, corrosion, needs replaced or rebuilt.

 

[Robb235]

Yeah, I’m familiar with the stuck injector issue. I thought it could be that, but I’m not detecting a gas smell in the oil.

 

[84rzv500r]

well if its not fuel and its not water and no one added any oil on ya... change the oil and filter and see what happens... ??

 

[Robb235]

well if its not fuel and its not water and no one added any oil on ya... change the oil and filter and see what happens... ??

Yeah, I dunno, it's weird. I got the engine warm on the hose, extracted the oil, and refilled to the correct mark on the dipstick. We'll see what happens from there I guess.

 

[84rzv500r]

there was a guy on the board whose TPS voltage was high... not high enough to keep the ECU from lighting the plugs like mine but it ran and he was getting fuel in the oil until he adjusted the TPS in spec...

My only issues seem to be the occasional random dry fouling of a plug and having the WRONG impellers... I have one heat range hotter plugs to stick in... I've got 20 hours on my repower...

 

[scokill]

Yeah, I’m familiar with the stuck injector issue. I thought it could be that, but I’m not detecting a gas smell in the oil.

there was a guy on the board whose TPS voltage was high... not high enough to keep the ECU from lighting the plugs like mine but it ran and he was getting fuel in the oil until he adjusted the TPS in spec...

My only issues seem to be the occasional random dry fouling of a plug and having the WRONG impellers... I have one heat range hotter plugs to stick in... I've got 20 hours on my repower...

For shits and giggles, I would pull the ECU and look for water intrusion or some other sign it may be compromised.

 

[Robb235]

For shits and giggles, I would pull the ECU and look for water intrusion or some other sign it may be compromised.

I think I'll do that, and also swap ECUs between the two motors to see if the weirdness follows the ECU.

 

[scokill]

I think I'll do that, and also swap ECUs between the two motors to see if the weirdness follows the ECU.

Even better!

 

[Robb235]

I think my next project is going to be adapting the trim system from the FX/FXHO skis onto my boat. I salvaged the jet pumps from the donor skis, along with the cable assemblies that control the trim of those nozzles.

 

[Robb235]

The big thing stopping me from adapting the trim system onto my boat has been how do I actually control the trim? I've been trying to brainstorm ideas, everything from some sort of locking shift lever, to electric motors to control the trim ring of the nozzles.

The jet skis used the QSTS or "quick shift trim system" if I recall. You pull a "trigger" then set the trim by twisting the left handle bar, similar to how you twist the throttle. Releasing the trigger locks the trim in place, either -10, -5, 0, +5, or +10 degrees of nozzle angle. I don't have handle bars, so adapting the QSTS doesn't appear to be an option.

There's another thread on here where I believe the guy used a trim tab actuator to control the the trim of the nozzles. I think he had the actuators in hand already, so it didn't cost him anything to use them to control the nozzle trim. I'm not sure how much effect trimming the nozzles will have on the XR1800, so I'm looking to keep this conversion low budget. Trim tab actuators are a little pricier than what I want to spend.

After doing some research, I learned that some Seadoo boats came with what's called Variable Trim System, or VTS. It looks like an electric motor either pulls or pushes on the trim ring in the nozzle. It might seem a bit taboo to use Seadoo parts on a Yamaha, but I think adapting their electric trim motor might be the best option to controlling the trim system adapted to a jet boat.

Certainly open to any ideas if anyone has any.

 

[84rzv500r]

how can it be taboo to use seadoo parts on a yamaha 50% of the standard boat and hull parts come from the same oem suppliers...

any port in a storm

 

[84rzv500r]

thats a lot of work... why not a yamaha YPVS push pull servo controller from a bike or a jetski cable hook right up tp it.... there are aftermarket controllers... i think they are just DC stepper motors and they might have an encoder too...

 

[Robb235]

thats a lot of work... why not a yamaha YPVS push pull servo controller from a bike or a jetski cable hook right up tp it.... there are aftermarket controllers... i think they are just DC stepper motors and they might have an encoder too...

I thought about repurposing my old power valve servos for this, but I seriously doubt they are strong enough to overcome the forces at the jet nozzle, and then be able to still hold the nozzle in place at any trim angle other than 0. From what I’ve read, the jet ski riders have to get off the throttle before changing the trim setting with the QSTS, and only when the new trim setting is locked in can they get back on the gas. Forces are too strong at the nozzle to move the trim from 0 degrees while on the gas.

Idea is to use a system that Seadoo already designed and retrofit it to the Yamaha. I picked up one of these VTS systems for less than $200. My plan is to hook up the red cables that attach to the trim rings up to this VTS motor, so that one motor is pushing/pulling both nozzles up and down. I will need to fabricate a bracket of some kind to hold the red cables in place at the VTS motor end.

They other cool thing is that Seadoo has a trim gauge that plugs right into the wiring harness of their VTS module.

 

[84rzv500r]

cool... I just pulled the pump off my donor jet ski (2006 FX HO Cruiser) if you want any of the trim/steering/nozzle parts i can send them to you... Im only interested in the shaft, impeller and stator housing.