Other 61X Powered Mini Jet Boat

[RBS145]

Part 2:

Added handrails to the windshield.


New 1/2" thick Full Width UHMW for bashing rocks. Cane with lots of extra weight for free.



Added a soundbar for a UTV, which is useless anytime the engine is running. So it's being removed and a comms setup with tunes is being swapped in.


Purchased a new rebuilt engine.
-61x/62t twin carb combo
-R&D Wet Pipe
-ADA 180 comp head
-Carbon Reed's
-Spark arrestors
-Dual Cooling W/sand seperators
-MSD Enhancer
-Full size battery for lights and other accessories


First trip was successful after the rebuild. But the engine and pump need lots of tuning still.

 

[RBS145]

Part 3:

Added a wrap, really easy and only $200 on Amazon



Ended up breaking a tine of the intake grate. Resulted in a bunch of bigger rocks getting through and abusing the pump. This was a Solas 12 vein with a SS wear ring and Hooker 9/15. It's pretty banged up, maybe beyond repair. I was thinking of going to a replaceable liner wear ring and a 10/16 impeller. The boat had plenty of holeshot and I might be able to squeeze a bit more top end with new engine. Maybe keep a spare wear ring and impeller in the boat. I was also thinking it may be worth doubling the number of tines to tighten the intake grate up, not sure if that would restrict the pump too much though.

 

[RBS145]

The pump protection bars seem like a no-brainer plus they add a nice little boarding step.
I'd be curious to see a list of typical repairs and areas to beef up on these.

Is that a teflon hull liner?

Yes sir, same thing as Teflon I believe. Heavy duty stuff! I think I've found a lot of the weak points and put them in the last post.

I'll be uploading a video edit of some adventures this summer.

 

[OCD Solutions]

Love the pics and the details. I really want to build one of these in the near future so I’m taking lots of notes.

How does the hull track with such a smooth bottom? I’d think a small chime of some sort improve steering although I guess the point is to be able to slide up and over almost anything.

Everyone says the 61x has more than enough power but I’m still thinking a small 4 stroke would be ideal based on improved mileage and sound levels. Comments about sound level anytime the engine is running and only a 25 mile range with an 11 gallon tank have me thinking a four stroke would be more than worth the added investment. Would it be too much power in such a small hull though?

 

[RBS145]

Love the pics and the details. I really want to build one of these in the near future so I’m taking lots of notes.

How does the hull track with such a smooth bottom? I’d think a small chime of some sort improve steering although I guess the point is to be able to slide up and over almost anything.

Everyone says the 61x has more than enough power but I’m still thinking a small 4 stroke would be ideal based on improved mileage and sound levels. Comments about sound level anytime the engine is running and only a 25 mile range with an 11 gallon tank have me thinking a four stroke would be more than worth the added investment. Would it be too much power in such a small hull though?

It is a very loose feeling as far as handling goes, the back end sort of drifts around corners. Which is actually not a bad thing depending how the river is, because you can keep the pump intake over the deepest part of the river easily. I have ordered a different style of trim nozzle that is supposed to help a lot with more thrust in corners from Minijet Inc here in Canada. I post some pics once installed. The easier it is to slide over obstacles the better for sure.

Definitely more than enough power in the 61x engine. It feels really fast on a shallow/narrow river already. If you watch any videos of the 4 stroke engines in these, they have all been trying to deaden the sound with Kilmat or similar. They also all seem to wear some kind of headset/hearing protection, these aluminum hulls resonate sounds like crazy. I installed a ton of Kilmat and closed cell foam to absorb sound. It helped, but it's still quite loud. That soundbar for tunes is coming out. I found a comms setup from SENA that you can play tunes and chat with the passenger at the same time. I also installed a 21 gallon tank which nets me about a 65mile range. I've never burned an entire tank yet in a full day of running around. Also, I would not even consider a boat hull without the taller windshield too. We get soaked even with the big window.

If you are looking to build up a boat and you live in the US. You should definitely be looking to buy soon, the exchange rate gets you a big discount right now. I just got back home from Vegas and $500USD cost me $750CAD. Ridiculous considering it's been at par before.

 

[fastgtfairlane]

Impros could fix up your impeller and probably repitch it to 10/16 for you at the same time. The stator veins look ok on the pump nothing a little bending and file work wouldn't fix. Sweet setup. Any mph numbers for the addition of the dual carbs and pipe?

 

[OCD Solutions]

If you are looking to build up a boat and you live in the US. You should definitely be looking to buy soon, the exchange rate gets you a big discount right now. I just got back home from Vegas and $500USD cost me $750CAD. Ridiculous considering it's been at par before.

I was looking at pricing on a 12ft kit this morning and I was doing the cost saving in my head. A low exchange rate is good for exports.

I bought a Limitless Tonneau Cover/Sled Deck out of Kelowna, BC earlier this year and had it shipped to me here in the US and basically got 40% off due to the exchange rate at the time.

 

[kevbo]

Make sure to tune the carbs a little rich of peak RPM or else your pistons may end up looking like your pump.

 

[RBS145]

Impros could fix up your impeller and probably repitch it to 10/16 for you at the same time. The stator veins look ok on the pump nothing a little bending and file work wouldn't fix. Sweet setup. Any mph numbers for the addition of the dual carbs and pipe?

Yeah, that's where I bought it all. I'm heading down south later this winter, I'll reach out to them before I head that way. I haven't had a chance to run GPS yet on it and the snow is flying up here now. I'll update next year, although it didn't feel much difference. It needs lots of tuning and that impeller was pretty thrashed already.

Make sure to tune the carbs a little rich of peak RPM or else your pistons may end up looking like your pump.

Care to elaborate? I'm not real familiar with these ski engines. I was seeing 6500rpm peak, builder told me to tune for 7200 ish. A new impeller and potentially a 10/16 instead of 9/15 will likely change that too. Might buy one of each pitch and go from there.

 

[RBS145]

I was looking at pricing on a 12ft kit this morning and I was doing the cost saving in my head. A low exchange rate is good for exports.

I bought a Limitless Tonneau Cover/Sled Deck out of Kelowna, BC earlier this year and had it shipped to me here in the US and basically got 40% off due to the exchange rate at the time.

Depending what type of rivers you run, a 12ft could be great. The lighter the better if you run out of water and have to push it. The rivers here change throughout the year and some channels are open one day, but closed the next due to flow changes. If you aren't worried about that, I would also like the extra space for camping gear and what not.

 

[kevbo]

Yeah, that's where I bought it all. I'm heading down south later this winter, I'll reach out to them before I head that way. I haven't had a chance to run GPS yet on it and the snow is flying up here now. I'll update next year, although it didn't feel much difference. It needs lots of tuning and that impeller was pretty thrashed already.



Care to elaborate? I'm not real familiar with these ski engines. I was seeing 6500rpm peak, builder told me to tune for 7200 ish. A new impeller and potentially a 10/16 instead of 9/15 will likely change that too. Might buy one of each pitch and go from there.

Depending on how tall the exhaust port is, it needs to turn at least 6800 with that pipe. If it is "race" ported then adjust the pump load so it gets on the pipe quickly. A freestyle pitched impeller is ideal. What I mean by "rich of peak RPM" is adjusting the top screws at full throttle while watching a tachometer. It is much safer to open them so the engine turns 20-40 rpm slower than the maximum rpm mixture setting. It is easy to burn a piston if the mixture is allowed to go lean of peak power.

 

[RBS145]

Depending on how tall the exhaust port is, it needs to turn at least 6800 with that pipe. If it is "race" ported then adjust the pump load so it gets on the pipe quickly. A freestyle pitched impeller is ideal. What I mean by "rich of peak RPM" is adjusting the top screws at full throttle while watching a tachometer. It is much safer to open them so the engine turns 20-40 rpm slower than the maximum rpm mixture setting. It is easy to burn a piston if the mixture is allowed to go lean of peak power.

Intake and exhaust ports were left stock, no additional porting. The builder said it's more reliable that way, which I cannot validate. I will keep that in mind when I get out in the spring to tune again. I'm going to start from scratch with the impeller change.