SUV Resurrection with 1.8L 4-stroke conversion

[TimeBandit]

So last year I was (finally) able to acquire a 2001 SUV1200. I wanted one several years ago, just wasn't good timing. I always admired Yamaha's largest production 4-seater Waverunner. The older I get, I need more comfort. I use my PWC like a boat mainly. I mainly cruise, island-hop, and fish, so the SUV platform just fits my lifestyle - all being just shy of an actual boat boat. Nothing against boats, I just down-size from a 24' cabin cruiser years ago to a PWC and have happily never looked back. Anyway, this SUV had a running 2-stroke when I bought it, so I was glad to have been able to ride a SUV. to test-ride it. First time on one - LOVED IT !! So smooth and stable.

As per the title of this thread, doing a 4-stroke conversion. Not a fan of the MR1 engine, so I'm dropping a 1.8L NA in this. Historically, most have dropped MR1s in these - and I get that. However, having owned and wrenched on both these engines, I really really prefer the 1.8L for a multitude of reasons. Those of you familiar with my past threads, know already I dropped a 1.8L NA from a banged-up donor VXR into my late 2005 FX HO ski. BTW, that has worked out extremely well all these past years. I've been searching for another 1.8L donor ski, yet covid got in the way, as house-boredom made everyone want to go out and get into jet-ski'ing, exhausting the used market supply and driving up 2nd hand prices! So while I'm waiting to find that unicorn donor ski, I am considering to just cannibalize 1.8L NA (VXR) engine out of my operational FX. After-all, it makes the most sense - yet I just hate the idea of being ski-less for a time during the conversion.

The main objective with this SUV resurrection is to end up with something that looks fresh and new, yet extremely functional.
Here's my short-list of goals and mods:

1.8L 4-stroke conversion
Complete hull repainting - top white, bottom black with air-boat silicone-epoxy under-coating.
Faux teak decking ÔÇô gray faux teak EVA foam marine mat
Customized sponsons
Dual-port thru-hull exhaust ÔÇô
Extended/lengthen ride-plate
Cleat additions
Bimini top
Electric bilge pump
External flush port
Water flag delete

- and if I do cannibalize my existing FX, I'll get the following mods already:

Dual lithium batteries with battery selector
Sierra marine starter solenoid
Water muffler (DIY)
Fat Bars ÔÇô handlebars, ODI grips, billet throttle trigger
MCCT (manual cam chain adjuster)
Anti-cavitation offset pump cone
Thermostat pisser
Hi-Flo Air filter
MOSFET regulator conversion

Anyway, this project is going to be a long one. It's just me, and well, I'm planning on going over this SUV from head-to-toe first - perhaps bow-to-stern is more like it. Lots of body-work modification to-do list, to include likely completely painting the hull top-to-bottom. I'm in Florida, have a residential garage, so the soonest I could get to paint is going to be late October unfortunately.

[K447]

What capacity fuel tank will you be using?

Would a Kawasaki 22 gallon tank fit in the hull and work with the Yamaha fuel pump and filler neck?

[TimeBandit]

Yes, I have given this topic a little thought. For safety reasons, I will not be using (aka modifying) the SUV tank. The direction I am leaning is using my existing FX tank. Honestly, I'm able to commute just fine to all my normal spots on that 18 gal FX tank.

That said, bigger is better - never know when that could come useful - so, interesting thought, regarding a larger 22 gallon tank. A tank from an Ultra 310 perhaps? I am open to that idea.
As for fitment, I think such a tank would have that desired "V" shape, yet I would need assistance with overall measurements - if you happen to have one of these laying around??
Looking at the fiche diagram for a 2017 Ultra, the filler neck looks to be on the opposite side ... however, the SUV has another filler cap on that side (originally used for the oil tank) so with minimal hose routing, this is feasible.
I'm also noting that the fuel pump top-end looks a lot different from Yamaha pumps ... so using my FX pump likely won't fit without modding the tank - again rather not alter the tank. However, it might be possible to wire-in the Kawasaki fuel pump, as I imagine the operating pressure should be very close. The only question would be fuel sender high/low resistance ranges, to work with Yamaha's cluster's fuel gauge readings.

[TimeBandit]

Things accomplished so far:
2-stroke removed.
Jet pump removed.
Fuel tank removed.
IB housing mod.

With the hull empty, I decided to get straight into the IB housing mod that will be required.
Referencing posts of those that have gone down the 1.8L conversion path, I know the IB housing needs to be bored larger to accommodate the thicker 1.8L drive shaft.

For those unfamiliar with SUV style mid-shaft IB housing(s) plural, it's basically the same design as IBs on all modern 1.8L Waverunners today. The exception, is that modern crafts use the mid-wall partition itself to provide a water-tight "well" interface for the IB and the drive shaft hose. On the SUV, the mid-wall is just a plain old mid-wall with a hole. Therefore, there is another housing part, an aft half of the IB housing made of aluminum that mates with the shaft hose and IB housing. Then once assembled, the whole thing gets bolted to the mid-wall partition. Therefore, the part I am modifying here, is that aft-half of the IB housing, the so-called housing "well".

Here is the backside of the aft housing "well" which attaches to the shaft hose. The OD is fine, and will fit the shaft hose. However, as you can see, the ID is around 28 mm. This is too small as-is. We'll need to hone that out to 31 mm at least.

So I found a local machinist, whom did a fantastic job.

Not only did they get the ID increased to 31mm, but they also cleaned-up the other side (which mates with the IB housing) to offer a better seal.

[smiley1234]

I am buying a 1999 1200 suv on Tuesday. It has a 2 stroke engine, in runs. I am wanting to convert to 4 stroke. I have looked on the internet for instructions and the ones I found the links no longer work. Can you steer me in the right directions for good instructions to covert my pwc? Thanks in advance.

[ERICSUV1.8]

For the fuel tank you will want to find a MR1 fuel tank from an FX this tank is same shape as suv tank minus the cutout for the oil tank and holds the same 18 gallons. The newer fx tanks do not fit properly. The MR1 tank also works with the 1.8 fuel pump so its just a few bolts and it swaps out easily.

[TimeBandit]

Was able to carve-out enough time to get most of the bottom hull painted. So it's gloss black around the outer-perimeter, while (at the moment) the under-belly is still left untouched. That's because, obviously, the ski is still on the cart. The plan, moving forward, is to free the ski up from the cart so I can roll-on air-boat coating (Fasco Super Slick epoxy). That coating will be tinted to a dark-gray, so the two-tone black & gray bottom will look quite updated once completed.

Here's an aft-view-
Couple of things to point-out:
The OEM exhaust-port (stbd side pump-tunnel) has been completely deleted - I glassed it closed. Probably the most obvious mod, is the new cool-looking dual thru-hull exhaust port centered. It took me a while to figure-out where I wanted the new port located, because the issue with the SUV hull, besides all the curvy surfaces back there, are those port & stbd bay storage-compartments - these don't permit all that much space on the hull inside for thru-hull locations. So situated right above the pump tunnel is a small flat area. And due to this area being a bit narrow, I went with a smaller port tip, which meant I needed two. A square port would have been really kit - but the only I found were right or left-hand. The ÔÇ£funÔÇØ will be in the exhaust plumbing later.

Also worth mentioning, new black scupper drain hull ports (OEMs were weather-rot white), and the rear tie-down hooks are now stainless. What is not evident about these hooks, is that they are much more substantial, plus I've laid-up added carbon-fiber backing inside. Not that I plan to tow with these, but technically I could.

Probably the coolest mod yet --> re-engineered sponsons.
Apparently nearly 20 yrs ago, sponson-tech was not all that much. If you look at the SUV's OEM sponsons, they are quite puny. I don't know if that has been playing a factor in the porpoising issues, and/or the rear breaking-loose in turns ÔÇô heck, I can't say I even know what I'm doing here, but nothing is ever figured-out by not experimenting! So that's what we have here.

The construction is quite-simple: basically 1 / 4ÔÇØ aluminum angle, and an 1ÔÇØ HDPE black spacer. The spacer is UV resistant, and I glassed-in permanent stainless backer-nut inside the hull.

The first thing to note, these are long - likely won't help much improving tight-turning/maneuvering. Hey, it's a SUV folks ÔÇô it's not going to be used much in scholium courses ÔÇô LOL. Therefore, my main focus was with stability on-plane ÔÇô especially at fuel economy cruising speeds. The increase surface-area these provide, I hope will support the rear better at the cruising speeds (not WOT). Yup, it will be interesting to find-out how these are going to change the riding characteristics. But for now, they just look darn-cool ! Oh, and the gray color is super slick coating. Not that these sponson need to be slick, just thought it made sense to put a durable coating on them, and matches the under-belly coating as well.

What's next?

So, again, need to get the super slick applied to the bottom. I'm building some pole ÔÇ£standsÔÇØ, so I can support/suspend the hull & slide that cart out from under.
Still working-out the supports and tie-down strategies ÔÇô safety is #1.

[TimeBandit]

Bottom hull painting is done !!

Sorry for the poor quality pics - it's hard to shoot gloss-black and dark gray pics inside the garage and have them show justice, but it looks great! Two-tone color scheme came out just as planned.

One slight change on the bottom treatment - I did not go with "super-slick".
You see, I only had one quart of it originally, so I needed to buy more anyways to do the entire bottom. After reading more feedback from others, not sure I want the bottom to be THAT slick. I thought about how often I am solo, and return to the ramp, that I need a little sticktion (yeah made that word up) when I drive up onto the bunks of the submerged trailer and climb off the ski onto the front of the trailer to latch the bow. And on the more aggressive pitched ramps, I usually keep it running in forward-idle and that keeps the craft well-planted until I shimmy onto the trailer and hook the bow. At that point I yank the lanyard (stretched to me standing at the winch) to kill the motor, crank it secured, hop in the truck and I'm gone.
Thus, if the bottom was too-too-slick, this might add an unsafe dynamic to something that is, well, a little sketchy already.
The OTHER bigger reason, was that super-slick did not seem to be ideally "re-coat-able" due to the added Teflon and anti-friction additives. It just won't stick to itself reliably I guess.
Rather, I wanted something that I can sand a bit and apply a new coat if-needed, or spot-touch-ups. So I went with the same product minus the anti-friction stuff, aka Fasco's regular "SteelFlex". That stuff is thick stuff, hard to apply, and doing it up-side-down was a real-thrill !! - Not ! Let's just say glad to be done - next Chapter . . .

[SUV1200]

These are great machines with the 1.8! I’ve built a couple and theres a guy in West Palm Beach building them on a regular basis.. they just got a 1.8 NA to hit 73 mph by flashing, heavier valve springs and a couple of other tricks.. toughest part is stopping the porpoising after 57 mph.. each hull seems to have it’s own issue.

[SUV1200]

I just had my SUV 1.8 re-gel coated and it looks brand new!

[Jjcrossan]

SUV1200 could you shoot me a private message as I am looking to build an suv 1.8 I am I the Caribbean and looking for someone that can turn key help. Maybe if you could send me the contact of tbr guy in west palm?

[nano]

hello everyone here is a suv fx sho 1800 fantastic transformation

[TimeBandit]

nano - many thanks for posting your SHO conversion ... very well done!!

Random thoughts & questions :

* I like the idea of re-glassing the motor mounts so you can use the 1.8L mounts instead of the 1200 mounts. I'm not there yet, but was thinking doing the same thing so I can use my donor VXR's Rhaas mounts.
* Straightening the exhaust manifold ... looks great! Whom did the work?
* Liking the black & white color scheme. What is that on the foot-well sides... carbon fiber?
* Really good work on the gauges fitment.
* Did you keep the SUV steering mechanism? If-so, what did you do with the OTS switch assembly? I ask, because I'm torn back and forth with converting the steering mechanism & OTS switch from a 2005 FXHO donor and thus keeping the 1.8L VXR's OTS functionality or not. I have not explored the feasibility yet.
* Tank? What donot craft did that come from - the SHO ski? Year?
* I do not see an added 2" spacer on the mid-shaft unit, which means you kept the 2" housing from the SHO pump. Understand this could cause control-cable length issues?? What was your experience?

Good job!

[SUV1200]

Nice Job! You went way out there on the mounts! My SUV mounts have worked fine on my mods. The 02-10 FX/FXHO Fuel tanks fit right in place. U just have to merge the 2 filler hoses. Let me know how the porpoising is! We're all working on solutions here in South FL..

[SUV1200]

To answer a couple of Time Bandits questions.. I let the OTS hang out somewhere plugged in. Creates no issues. The fuel tank question, I answered in the block before this one. Nano converted a SUV tank. If ur doing a MR1 conversion, you are better off using adapter plates to shift the engine forward 2" instead of ripping up the hull inner liner. The local conversion guy leaves the rear SUV mounts in place for 1.8 conversions and moves the front mounts. You typically need 2" extensions for the controls (pieces can be bought on Amazon cheap). You need a 2" spacer from a 2002-2008 MR1 propulsion system for use behind the rear transom plate. It's called Wear Ring#2 in schematics.