Yami SUV 4 Stroke Conversion..Here We Go Again!

[SUV1200]

OK.. I now have a good 2000 SUV Hull with power train removed and sitting off to the side. My plan is to convert it to a 4 Stroke over the next 6-7 months. I've read the threads that are available and talked to some "Experts". I need to see which Yamaha set-up makes sense to work with... from what I've heard, the 140 can be a problematic engine, but the 160 HO's are OK, with exception of the first year model (2004?). The 180 Supercharged is a nice set up as well and looks to fit very well (after making some mod's).. I've also heard that a 110 should make the ski do 50 MPH since the 110 shell weight is not that much less than the SUV. The 160 appears to hook up to the rear mounts, but the front mounts need to be moved. I also heard that the engine coupler shaft from the SUV should be used to sit the engine back further for the 160. I'm not sure if the pump assembly from a 160HO will fit properly? I also heard the SUV1200 prop should be changed for a 160. I will use the ski for cruising and want some economy. I'm OK with 50 MPH.

All insight for decision making is appreciated! Thanks....

[jzellers]

Whichever engine you use, you'll need to use the intermediate shaft from the FX or VX. The SUV intermediate shaft is longer and would move the engine farther forward. I have the 2004 160 in mine and I never heard of or have experienced any issues with the engine or electronics. The entire driveline out of an FX will fit the SUV. That's how I did mine. The Pump is the same other than the center hub casting being larger on the HO than the SUV. The drive shaft, bearings, and seals are the same, with the exception of the cone o-ring.

Any of those engines should get you to 50. Some will obviously get you there a lot faster There's a guy in South Africa that has done a few conversions with the VX110 engines but I never could get a response from him on some performance numbers. His goals were fuel economy and low noise for fishing. He does have a youtube video on it with more details.

[SUV1200]

It looks like I have my Donor ski... 2003FX HO with rebuilt engine, new mounts and wear ring/propeller. Will know for sure by Friday when I haul it home. It's actually a nice ski and I hate to pull the drive train, but I'm on a mission! Will sell the hull and trailer once I've removed my parts needed for the SUV. I'll take many pics once I begin the transformation... Have learned a lot reading the other articles..thanks all!

[SUV1200]

I now have my Donor ski... a 2003FX with 2005 50-Hr FXHO engine, new mounts and wear ring/propeller. Hull is already spoken for, but will sell the trailer.. and away we go!

[jzellers]

Excellent! It shouldn't take too long and you'll something really cool.

[SUV1200]

It has the FX140 Propeller still. It went at least 56 on my test ride with more to go.. Don't know if I should keep that prop or change to a FX HO prop?I like the 04 Dash better and wonder if that will be a direct swap..

[SUV1200]

OK Joe, here we go. So far all has come apart easily.. nozzle and pump assembly and shaft.. Do I need the ride plate and transom plate/speedo wheel, or do I stay with mine. I have the 2" spacer out. I'm trying to understand what I need to leave in the FX hull. I believe I need the throttle assembly/handle, fuel tank, water box for the neck of it? fuel filler hose to couple my assembly.. input appreciated!

[jzellers]

As far as the impeller goes, if you have a stock FX 140 impeller, it's a 12/18 just like the stock SUV impeller. I would go to the 14/20 that the HO uses. I used a stock 14/20 and changed it to a Solas Dynafly 14/20. If you're going to buy one, I'd get the Solas to start with.

You'll have to use the SUV ride plate, speedo sensor, and intake grate. The FX speedo sensor mounts differently. Use the spacer, pump, and nozzle from the FX. The nozzle from the SUV will work as well. Remember to order OsideBill's cable extensions so the SUV cables will work with the 2" FX spacer. You're correct on the other parts - you'll need the throttle cable (the lever is the same for both), gas tank, water box. Something to keep in mind is that you'll need all the water hoses and fittings, plus all the fuel lines from the FX hull. I'd keep the FX hull until you know you're done with it.

For the dash, it's not a direct fit by any means but for me it was just about taking time to make it fit properly. Just plan on spending a lot of quality time on it with a Dremel tool. The FX gauge assembly will need to have the top mounting tabs tabs cut off of it at least. Depending on how you do it, you might have to cut off some of the plastic around the housing to make it fit under the SUV cowl. I had a couple pictures in my thread.

[SUV1200]

Thanks Joe, Can I just use the SUV propulsion assemmbly so I don't have to add the 2" cable extensions? Otherwise, I don't know where to find them now. What does the extra 2" do for it?

[jzellers]

To get the engine to mount in the right spot, you have to use the intermediate shaft from the FX, which is 2" shorter than the SUV. To get away from using the 2" spacer, you'd have to shorten the driveshaft by 2". It's hard to tell what the value of the pump being 2" farther back is in an SUV. Even though I have a 2-stroke SUV, they handle different enough just from the weight difference so I can't say one way or another whether it's good or not. I know that mine handles good with no porposing while one of the other guys complained about it and had to adjust the trim to get around it. I would buy the extensions and be done with it.

[SUV1200]

Thanks again for the insight.Where can I get the extensions with Bill having left us (so sad)..

[jzellers]

Yes, very sad indeed. I had no idea when I first posted about the extensions because I was out of town and not on the forum all that much lately. I thought I saw that someone else had them too but I can't find them now. Hopefully someone will chime in on who may have them or maybe someone has an extra set they will be willing to sell.

[SUV1200]

If I can get pictures, I may be able to have some fabricated...

[jzellers]

That's easy - http://www.greenhulk.net/show...ble+extensions. The trim extension is a different size and the stock wouldn't necessarily need to be hex.

[beerdart]

m5 for the trim and m6 for the steering 2" long with a threaded stud in one end.