MR1 HO to 1.8L HO engine swap - gen 1 FX HO

[TimeBandit]

I've got an '05 Yamaha FX HO in need of a new engine. Rather than provisioning an obsolete MR1 HO replacement, I am going to swap-in a new-ish 1.8L NA engine. Likely not on anyone's top-10 conversion list, but I'll go ahead and document process as I go.

First, why the old gen 1 fx hull?? Well, I personally use this craft to augment my solo fishing excursions, and some LD cruising in the intercostal areas. Aside from the SUV couch, these older FXs are heavier, plowing through the chop better with their deep v-hull, almost offering a boat-like ride. Plus, mine is already heavily modified & rigged-up with rack and fish-gear. Plus, being older - not afraid to get it dinged-up a bit. They just don't make 'em like this anymore - she's a keeper.

Conversion feasible ??
Yes. I asked around, did tons of fiche research. Plus, its been apparently done already, using an SHO. Yet all you really have to do is appreciate the fact that manufacturers like cutting costs whenever they can - and re-using existing design is one such strategy. From 2004-2008, the MR1 HO powered the FX fleet. But there was also an over-lap year in 2008 when the 1.8 came out to power the FX SHO line. Same base hull design with either engine, therefor we know right off the bat that the new 1.8 was designed around the MR1 footprint. It also means we can retro-fit the 1.8 into the gen 1 FXs.

Parts short-list:
Complete 1.8 NA engine, with ALL the electronics ÔÇô wire harness, security box, ecu, gauge/cluster, etc. . .
Complete drive-train ÔÇô IB assembly (coupler, bearing, mid-shaft), jet-pump stator/duct (which includes the drive shaft and impeller).
Water-box/exhaust ÔÇô maybe.
Tank/Fuel pump - no

Yup, lookin' like a complete donor craft will be needed.

Speaking of donor candidates:
Trying to keep the conversion very basic. My preference is no older than 2012. This is because the 1.8 went through some revision tweaks which came out in that year. Still need to do a serial number check to be sure.
That said, I also don't want anything younger than 2014. Aside from cost, the 2015-on all have RiDE. Not saying it couldn't be done, but I like the manual trim and reverse on my craft.
As far as model types, I'm targeting the NA engine for the fuel economy. This includes all newer FX HOs, Cruisers, and the VXR/VXS fleet. Trying to find one with hull-damage, but a VXS would be the entry-level of them all, being the most vanilla offering of the 1.8 NA.


UPDATE
Donor Found !
I just recently scored a 25hrs fresh-water 2012 VXS, with the newer 1.8 motor. The ski has a bit of a 'mark' (cough cough) on the front, but the water test was good. The OEM plugs were old, yet ok. Scoped the cylinders,oil was clean, and the YDS report came back clean, so we are good-to-go!

Now the fun can begin. . .

[TimeBandit]

Gauge / Dash Cluster swap

Let's get the easiest out of the way 1st!

{ Installed on the '05 FX }

The gauge/cluster swap is plug-n-play - bolts right up. The VXS cluster has exactly the same wires/connectors, LOL it even looks exactly the same as the old FX gauge from 7 years prior. The only real difference is the RPM readout is not so tall - aka for the slower spinning 1.8L.

Throttle cable swap:

{ '12 VXS throttle assembly & TPS sensor }

The '12 VXS is 1st-gen fly-by-wire, so it still technically uses a steel-cable linkage to the TPS sensor located inside the hull, on the stbd front bulkhead. To extract it from the VXS, it's best just to unhook it from the throttle lever, and feed the cable end into the hull. Unbolt the TPS mechanism and detach the wire harness plug and the whole thing is freed.

{ TPS sensor bolted inside the FX hull port side }

Mounting it in the gen 1 FX was trivial. I followed the same legacy cable routing through the handlebars/hull, so just needed to find a home for the TPS mechanism. I decided to go to the port side bulkhead nearest were the security box mount is already on the FX - I'm gambling the VXS harness will make the reach. I pre-drilled 3 under-sized holes into the inner SMC liner, then used SS lag bolts with 5200 as added measure. Secure enough to take a wave-pounding for sure.

UPDATE
The engine is fully extracted from the VXS hull and resting on the workbench. Wire harness is completely out as well. I'm going to take some time here and replace a bunch of hose clamps for 316 SS Aba's.
I'm noticing a little bit of coolant weepage/residue around the thermostat cover, and a lot all around the Water Jacket Manifold (WJM) cover. Sorry no pics, but looking at the fiche, I see this WJM cover has undergone some revision since 2012. Pondering if I should get the newer cover as it looks in the pictorial to be more formidable/reinforced.
Another update:
Part arrival. Turned out that "newer" WJM is of plastic. This means I need longer bolts to make up the thicker part. In the end, it work well.

[Mizarael]

Hey I have questions how fast u go suv and I have top speed problem is nose of suv goes up and down when is plane I move trim up down center I can't get dis to stop going up and down my swap is sho 1.8 help

[slociviccoupe]

Just for others sake should see if the older cluster works with the 1.8 electronics.

[TimeBandit]

Drive-train:

With the engines removed from both skis, I had a chance to examine & compare the two drive-trains.

{ IB comparison : '05 FX HO ÔÇô '12 VXS }

First, I took a look at the IB, coupler, & mid-shafts. As you can see above (pic), the VXS (which shares the same p/n's as 2nd gen FXs) is much more formidable. Larger diameter coupler & larger mid-shaft receiver. The receiver is a tad shorter, but the impeller drive shaft is equally longer. The bolt-pattern is the same, and the IB to partition-wall seal is the same diameter.

{ Duct/stator comparison : '05 FX HO ÔÇô '12 VXS }

Next up, is the impeller duct(stator) assembly. The old FX shaft is a measly 20mm, while the VXS is 22mm splined. The stator housing, while hosting a larger shaft will bolt right between the same nozzle and impeller housing. This means this duct assembly is all you would need to swap - rest of the jet-pump can stay.


.....
To the old gauge/cluster question . . . if I were a betting-man . . . I'd say it would work fine, because the gauge cluster is simply a data receiver to the YDS protocol. i.e., if you look at the wire diagrams for either the VXS or FX HO, there is a unused plug for tachometer signal (non-analog models). Therefore, these fully digital clusters get RPMs from the data stream the ecu sends.

[TimeBandit]

I was able to successfully get the VXR impeller/duct assembly installed in the FX HO pump.
The VXS's impeller was chewed-up some from the PO. Went with a Solas.
Everything mounted-up perfectly with the FX's existing pump nozzle & impeller wear ring housing.

(Drive shaft splines peaking thru the mid-wall partition)

All that is remaining with the drive train business is to grease & mount that VXR IB coupler.

Next up - the hull's engine stop/bumper pads. . .

[dixon0001]

Keeping it coming

[5ecu179]

Looking good lets see more pics

[slociviccoupe]

Might have very slight issue, which I haven't verified is the water feed line size from the transom plate. Believe it's larger for the 1.8 engine compared to the mr1. You can take fitting out of old transom plate and open up your fx transom plate and press in fitting.

[TimeBandit]

Engine Stopper Pads :

Let's talk engine bumpers/stoppers. These are the two (fwd & aft) rubber "pads" mounted to the keel of the hull, just underneath the engine. They don't seem to directly support the engine per say, as there is usually some air-gap between touching the actual engine. I can deduce during situations of abrupt lateral and horizontal forces, these are intended to absorb, stabilize, and minimize the engine from severely shifting out of position, and without this added support it might make the craft more susceptible to breaking engine mounts and/or hopping out of the drive coupler. Regardless, Yamaha saw fit to have them, so it is only proper to also preserve their function in this engine swap.

(comparing the '12 VXR to the '05 FXHO stopper pads)

As you can see in the above pics, there is an obvious difference. The aft pad seems like it may swap just fine, but the fwd pad is completely different, in both shape and mounting holes. Now remember, in this swap write-up, I'm dealing with a 2012 VXS donor, so I can't speak if FZRs or 2nd gen FXs will have more or less "compatible" pads.

Aft Pad :

Since it appears to be the easiest, let's address the aft pad first. . .

( VXR aft pad test-fit into the old FX hull )

The VXR pad will indeed bolt right in-place on the FX hull. Position/offsets seems good. Pic above is the pad test-mounted in my old FX hull. However, after meticulous measurements, I have determined the pad is roughly 10mm too thick (high). No, I did not drop the 1.8L in just to confirm, but all measurements indicate, at best it will significantly touch the engine, and at worst prevent the engine from being fully lowered into position. Therefore, the logical "fix" would be to simply shave 10mm off the pad (maybe with a belt-sander) and call it a day.

Fwd Pad :

( fwd pad kinda placed into theoretical position - not a good fit )

There are two issues with using the forward VXR pad;
a) for starters, like the aft pad, it is also about 10mm too thick. Being cupped/curved it would make shaving it a bit more a challenge to preserve original shape.
b) the mounting holes don't line-up. Not a big deal to drill new holes in the pad, but then this means I'll need to find the exact position/offsets.
Ok, perhaps more research is needed. . .

Fiche Research :

Before I go hauling-off modifying these VXR pads, I decided to scan fiche once more. I noted that in 2008 when the 1.8 and the MR1 was first both used in the same FX hull, the 1.8 has its own set of pad part numbers - no surprise. But what is interesting, is that these numbers are only used for '08 & '09, then another set are used from then on until the major FX hull change. So, these '08 legacy FX pads are likey THE best compatibility for my old FX hull and the 1.8L. My guess is that the inner FX hull liner dimensions may have changed when going to nano-Xcell hulls, which is why we see only a 2 year run on them. Perhaps I should order a set and see . . .

Legacy FX 1.8L pads (2008 & 2009) :

Hoping they are still in stock somewhere, I roll the dice and ordered a set.

( set VXR pads compared to a set of '08 legacy 1.8L pads )

Pic above are the 2008-09 legacy 1.8 pad set compared to the VXR pads. The aft one is a bit of a (small - lol) disappointment, but man, jackpot on that front one! Look how the underside contour matches the old FX hull hump. Cool, that solves the offset position issue too. And, yes, they (as I predicted from my previous measurements) are indeed ~10mm thinner.
Not so fast . . . not a total win. The fwd bolt fasteners are still not lined-up. But given what I now have, I'm confident these will work fine moving forward.

( installed '08 legacy 1.8 pads in the '05 FX HO hull )

So, we finally arrive to point that the VXR donor pads are useless to me. Best course I have was to order the oem 1.8L pads that came with the '08/'09 Fxs. Pic above shows a promising install, but I can't confirm until I get the motor dropped-in for the first time.
Stay-tuned.

Looking good lets see more pics

Darn "pic whores !!!"
LOL

Might have very slight issue, which I haven't verified is the water feed line size from the transom plate. Believe it's larger for the 1.8 engine compared to the mr1. You can take fitting out of old transom plate and open up your fx transom plate and press in fitting.

Thanks for bringing that up. I have not had a chance to compare the size on my VXS donor yet, but I will post up when I do. My guess is that you are correct, likely just a slight issue - if any at all. It's nearly at the source supply so the pressure might just compensate the volume. I'm guessing it could come more into play for those doing SHO conversions (due to the added supply demands to the intake cooler). For now, I think I'll let it be, unless some issues arise during sea-trails.

[TimeBandit]

Engine test-fit

I finally had some time to test-fit the 1.8 into the old FX hull for the first time. It was the moment of truth ! Will it fit . . . . . . . .
YES !!
It was actually easier than the old MR1 engine. Ample space all around. The engine bumper pads were in perfect position, and all four engine mounts lined-up. All appeared to be a really easy fit.
Ah, but a closer look at the couplers presented me with a slight issue :

{ couplers mis-aligned }

Initially, I had a bit of an issue aligning the coupler. Above pic shows roughly +1mm higher on the engine side. This was not good due to the fact I can't un-shim something not shimmed. First check was the those engine bumper pads again - yet a mirror showed an 1/8th inch space (perfect).
Next, I went to verify the Rhaas mounts against the VXR oem mounts :

{ measuring rhaas & oem mounts }

As it turns out, my Rhaas after-market mounts appears to be a whole 2mm taller than the VXR mounts. This is because the Rhaas were spec'ed to the FX HO. So this, combined with less give, sets the 1.8L up a hair too high. I don't have the original '05 mounts to measure, so I can't say if the oem FX are thicker. Obviously, anyone else doing this swap, would just opt to use the VXR engine mounts and be done. But I really wanted to keep my upgraded Rhaas mounts, so with a lot of time on the belt-sander (cough cough), I was able to get the Rhaas down an additional 1.5mm. This mod just so happen to be perfect, as I was able to get good coupler alignment without using any shims.

{1.8L inside 2005 FX HO hull }

[dixon0001]

I'm sorry I cheated on my build got someone else to do it so not much input I can give Dropped both skis off and picked it up 3 days later a cost of 300 pounds.had one error code but all sorted now just connector block. It's all running just need a water test before I start on the outside

[TimeBandit]

Air Filter Conversion

I had time to get the air-filter sorted-out today.

The VXR has a rather bulky air filter box on the port side of the engine bay. Aside from my old FX hull not having these bolt locations available, I decided to abandon the VXR box and go for an after-market "upgrade".

I bought a R&D Pro Comp Cool Air Filter from Riva Racing (item 200-01805), with initial thought that it might slip right onto the end of the ETV. Well. . . now with the engine actually mounted, it sadly does not clear the fuel tank in the FX. Because the naturally aspirated 1.8 has the ETV forward of the intake manifold together with the shape of the FX HO tank, it is just way too forward for this after-market air filter to install where intended. So with much pondering, I decided it is best to place the Pro Comp off to the port side so I could re-use the VXR's air plenum.

Being that the Pro Comp is so light, it will not take much to hold it in-place. I fabricated some custom bracket hardware from some scrap aluminum.

{ R&D Pro Comp with custom bracket }

For good measure, I also added some glue to eliminate the risk this would vibrate loose, thus risk ingesting hardware.

{ Pro Comp part layout with custom adapter tube }

Now on to the VXR air plenum. No default way to attach the Pro Comp to the VXR plenum, so I had to also fabricate a composite tube "adapter" (see above pic). Basically found a spray can with the ideal diameter needed, which allowed me to lay-up some carbon fiber & epoxy resin. Doesn't look pretty, but functional and strong indeed.

{ Custom Bracket FX hull mount location }

The pic above shows how the custom bracket braces the back-side of the Pro Comp filter. The hull drill locations have external bolt heads, but these are completely covered when the seat is installed. For this reason, I used smooth head bolts.

{ Completed Pro Comp Filter install inside 2005 FX HO hull }

I hate butchering perfectly new parts, but the fit was still too long by 3/4th of an inch. So I needed to cut short the Pro Comp hose end (see E). The result is that the custom tube fit so tight no need for a clamp on the filter side. By the end of the day, I have the air filter business sorted out. Once all is fasten-down and tight, this install is quite solid with plenty of vibration-give to it. As a bonus, the crankcase breather hose routed right into perfect position (see A). I abandoned the air plenum oil breather port (see B), as the custom tube insert covered the hole. Bracket bolts (see C), and relative ETV location (see D). I also did a ribbon-delete while here

I'm sorry I cheated on my build got someone else to do it so not much input I can give Dropped both skis off and picked it up 3 days later a cost of 300 pounds.had one error code but all sorted now just connector block. It's all running just need a water test before I start on the outside

LAZY !! Just kidding ! Hey, no worries. Time is money, glad you got it done, and for that price - you got a good value, because there is a lot of labor to do this job.
Can't wait to hear a report on your water test !

[TimeBandit]

Exhaust Install

Completed the exhaust system today.

{ comparing both stock hull configurations }

Comparing the two crafts indicated some obvious differences. Mainly the size of the water box intake port, and the hull's partition cut-out (see pic above).

{ water boxes - 2012 VXS left / 2005 FX HO right }

First order was to pull-out both water boxes, and get a side-by-side look at them.
The exit ports are the same so this mean I can attempt the oem FX from that point out. In case anyone is curious . . . I like the extra rear storage bin on these older FX's, so I really don't want to carry-over all that VXS resonator business if I don't have too.

So add to the conversion-list that the donor water box is indeed needed. The 1.8 engine has a much bigger link port than the MR1. However, the overall box itself seen a tad smaller ÔÇô maybe an illusion.

{ widening the FX hull partition }

The above pic shows the VXS water box now inside the old FX hull. The line-up of the intake port is not quite good, so I did some small modifying-work on the partition access cut-out, making it wider towards the bottom side.

{ 1.8L exhaust header mounted }

SUCCESS! The above pic show the exhaust header finally mounted. Everything bolted right-up smooth and the fit is great, but I do have reservations about utilizing the old FX parts from the water box exit port and on. The FX just looks more restrictive compared the the oem VXS setup, so I'm wondering about throughput efficiencies and not cooking anything with that bigger 1.8L motor. A part of me says it should be fine (for stock performance), because while the motor MR1 is 700cc less, it also spun much faster, thus exhaust flow volume might be fairly close at the end of the day. Next, the 2008 FX SHO 1.8 was essentially the same exhaust components as my 05 HO with a resonator added. I'll have to wait for sea-trails on if to get the missing resonator, or go for some type of Riva 'upgrade'.

Now it's time to get on to the electrical business. . . .

[Smokes]

Nice work.....