Jet Boat Observations

[Gunny]

Well folks Today on the Delta in a Jet Boat "For The First Time" was a hell of a deal. Temp was right around 50 Degrees and that was if you where setting still and not running real hard. Once a feller hit that Warp drive it was cold and damn cold.
Today I had to take my big Boat a cruiser over to Waltons boat Yard in Rio Vista for new bottom paint. Weather was nasty but it is a cruiser so how bad can it be? I made the run up Three Mile Slough and into the Sacramento River and was there in about a hour or so. After I got back to the Marina i though I would take my brand new "To Me" jet out for it's maiden run. Got the boat launched was real easy she slid right off of the trailer and if I had remembered the plug all would have been well. Trouble with that is that word "IF". Well what can I say I was a little excited what with my first Jet and all. Get the boat grounded back on the trailer install the plug and found out right quick that the Bilge pump worked just great. Boats back in the water and we are headed out to the San Joaquin River and up the Three Mile Slough for a little run to see just how fast this Jet is. Got my Lowrance GPS in my frozen hand and after I showered down it said 78 and the boat is still pulling real hard, but there is another Cruiser running the Slough and i slowed down for her wake, didn't want to hit that wake at no 78 MPH not with the water temp at 51degrees, I may have needed a shower but not at 51 degrees. Turned around and after the water calmed down some I headed back this time I dropped the hammer the GPS says 89 mph and this little 454 pumped Hawaiin is still pulling even at that speed. So I got a question. One is just how often does GPS complettly fail? And two: How fast do these damn little bitty boats run?
The observations part: I bought this boat becuase you guys where having so much fun planning that get together and it sounded just to cool to miss some of that. I also had a very personally reason, I am trying my best and damndest to find some way to recover from one of those life changing accidents, well accident is not quite right I guess, the feller with the RPG did not have any accidental feelings at all. After many operations the Doctors say water thearpy is the best way to finally get my mobility back. So the recommend some stupid indoor swimming pool full of strange people, getting half naked and sharing a hot tub with them. Weeeelll Not this old Marine. So I says to myself "BOAT" Huuuuummmmmm Boats go on the water Right? You gotta have water for water thearpy Right? Hell man I can fall outta of a boat and there's not only the motivation but real water thearpy Right? So I start buying boats, if one is good a whole damn big bunch of boats would be even better Right? So know I have three boats, whish I had started this fleet with this Jet Boat then I would have needed only one boat.
Today I did find out that Jet Boats are damn hard to steer while trying to get it on the trailer. There is no "Neutral" In a Jet Boat. That a tunnel ram with two 650cfm Holleys on a .060 over 454 making 12.5 to 1 compression does not like to idle, not at all!! That there is "NO" neutral in a Jet Boat, and I needed one real bad. And most imprtant of all that 50 degrees air temps and 89 MPH in a Jet Boat on a cold, Nasty, drizzling day on the Delta is more fun than this Marine new there was to be had ever!! Wish I had done this 20 years ago!!
Gunny
PS Did I mention there is NO DAMN NEUTRAL in a Jet Boat??
Picture is of my 27 ft cruiser right after she came up on plane, right in front of the Barges on the San Joaquin River.

[jbone]

Gunny,
Today I did find out that Jet Boats are damn hard to steer while trying to get it on the trailer. There is no "Neutral" In a Jet Boat. That a tunnel ram with two 650cfm Holleys on a .060 over 454 making 12.5 to 1 compression does not like to idle, not at all!! That there is "NO" neutral in a Jet Boat, and I needed one real bad.
That is some funny shit. I went throught the same thing when i switched from prop to pump.
By the way, Thanks for your service to this country. "Your a good American."
J

[JetBoatRich]

sounds like you had fun and the boat did what it is suppose to do :cool: Congratulations :cool:
As far as steering, you will get used to it and be an expert in no time :cool:

[LUVNLIFE]

sopunds like ou had fun and the boat did what it is suppose to do :cool: Congratulations :cool:
As far as steering, you will get used to it and be an expert in no time :cool:
Rich please drink some coffee before you begin to type so early in the morning :D
Congrats on the maiden voyage Gunny. :cool:

[BigDoug]

Man you aint lying about that Cale.. :cool:

[lucky]

gunny ya got to turn dem dam jet boats off - Off is neutral -- congrats on the jet - 89 is pretty respectable for a jetter -

[YeLLowBoaT]

Glad too hear you had a good time. 80s is very respecable. You got me beat... I am hoping for high 60s low 70s, on a very light load.
When it comes to jet boats if your not on the gas you have NO steering. You can get a fin to help some at low speeds. Give it a few trips you'll get it. When it come to neutral you can get pretty close with about 1/2 way to revrese... its not perfect, but it works.

[JetBoatRich]

Rich please drink some coffee before you begin to type so early in the morning :D
Congrats on the maiden voyage Gunny. :cool:
what ever :coffeycup you figured it out :crossx:

[Robbie Racer]

Gunny, you must have one hell of a well built 468" motor to hit 89 mph in a non tunnel jet boat. That is a very impressive number for a non-tunnel jet. You mentioned it had 12-1 compression. I hope you aren't running 91 octane gas in it with that kind of compression. If you are, my guess is that your motor's not going to last very long. Good luck and have fun.

[Cas]

Gunny,
Lots of fun, isn't it?! :)
As posted above, thanks for your service to our country to help give us the freedoms of being able to do the things we do.
Being you're just down the road in Sunnyvale, you ought to hook up with a bunch of us jetters sometime. You can find out what's on the agenda in the coming months at Laid Back Boaters Forum (http://p210.ezboard.com/bclassic***boats)
All the outings are a lot of fun with good people and good food.
You can also see lots of pics from past outings on LBBA Website (www.laidbackboaters.com), just click on the Past Events link on the left hand side of the page. We already have a few current and former military, as a matter of fact, one of our members was stationed in Afghanistan 2 years ago when he found out about us.
You will also be able to read a little about our Tower Park deal in Hot Boat magazine in next months issue.

[Gunny]

Robbie,
The Speed of 89 really surprised me as well, and I mean really surprised me. While this is my first Jet Boat its not my first Rodeo, that amount of speed just did not make sense to me. It was on my GPS and they are not "SUPPOSED" to lie. Now with that said tomorrow i am taking the boat out again and we will see what we see, this time with two Gps units.
The 12.5 to 1 compression number came from the feller I bought this boat from, so I really am taking that with a grain of salt as well. I have the reciept for all of the parts in this fresh motor. The paper work says the pistons are JE 12.5 to 1's. The seller advised me to use 91 octane, your comment has me wondering. What would be your recommendation?
Luckey,
No problem turning the damn thing off, it did that part real well on it's on. Maybe the boat knows more than i do, well hell thats not really a surprise I guess.
Gunny

[YeLLowBoaT]

Here is a way to test to see if you don't have enuff octane. I know it talks about a dyno of 1/4 mile but I am sure you could do the same thing with repeated 10 or 15 second runs. I really don't see why it wouldn't work doing it that way instead of a track. This is a cut and paste from a larger artical Writen by B. Fulper..
Plus you get to make some high speed passes :D Hope it helps.
Octane by definition is a detonation resisting chemical. I'll get into it further in my book, but for now let's do a test to see if you're cheating yourself out of power, and possibly hurting parts. There are two ways you can approach this. Is there a chassis dyno in your area? or can you go to a race track to test? You'll need to do one or the other. You may have heard that you can twist the distributor advanced until the engine audibly "pings," but this is absolute foolishness. This is not an opinion, it's a fact. All you learn is; at the point it pings, it's too far advanced. So? It does not tell you if that you move the timing back 2 or 3 degrees, as the proponents of this test would have you believe, that you've achieved "optimum" timing. That this is the spot that's the engine will make the most power. We need to find the engines sweet spot, while under a load.
OK. We're going to capsulize this guys, so don't be pickin' me apart. Get to the track or a chassis dyno. Bring along five gallons of 108 or 110 race gas. Make sure you have less than five gallons of your regular fuel in the tank at the start of the test. Check your timing at 2500 to 3000 rpm without Vac. Adv. hooked up. (Capsule#1; dist. is assumed to be working right.) Make a dyno pull or a run as-is. Record the mph. We're not concerned with e.t. as the mph reflects your h.p. Advance the timing three degrees. Make another run or pull. Did it slow down, run the same, go faster? If it slowed down, pour in five gallons of race gas. (Do not use 112 or 115 octane.)
If it ran the same, or went quicker, advance the timing another three degrees and make another pass. Keep advancing the timing three degrees until you find the spot that the car slows down. At that point retard the timing three degrees, then add the race gas. Make two more passes. Did the mph come up? Yes? Then advance the timing three more degrees. Make another pass and? what happened? More mph? This tells you that you are not meeting the octane requirement on 93. Did the car slow down? Make another pass just to make sure the mix of fuel has gotten completely into the carb. If it slows down it would tell you that it doesn't need the extra octane. Also, if the car went quicker on the last pass, add two more degrees of timing and make another pass. Quicker or slower? Quicker tells you it really needs the mix of fuel.
Also, understand this. Too much octane will also slow the car down. That's why there's three basic levels at most gas pumps. You already know that if you put too little octane you will lose power, but did you know that you will also lose power if you put in too high an octane. The burn rate is incorrect, and while you will not detonate, you will not burn the fuel as efficiently. You'll get less mileage and have less power. So that's why I said not to use 112 or 115 unless you mix it two gallons to four of 92/93 octane. 108 mix 4 gallons to 5 gallons of 92/93.

[Robbie Racer]

Robbie,
The 12.5 to 1 compression number came from the feller I bought this boat from, so I really am taking that with a grain of salt as well. I have the reciept for all of the parts in this fresh motor. The paper work says the pistons are JE 12.5 to 1's. The seller advised me to use 91 octane, your comment has me wondering. What would be your recommendation? Gunny
Gunny, I'm no expert on motors but I hear from others that as a general rule of thumb when using 91 octane gas, is that if you have standard heads you should keep the compression at or below 10-1 and if you have aluminum heads, you can get away with another half to one point of compression depending on optimum timing. I have not heard of anyone that has been able to run 12.5-1 compression on 91 octane gas (for any length of time) without causing detonation related engine damage. You might want to do a good spark plug check after a WOT run to see if you see any aluminum specs on them or if the strap is still there. One other thought is that you might want to post that question about maximum compression on 91 octane gas over on the gear heads forum. I'm sure there are more knowledgable folks there that can share some of their experiences as well. I would think that if you knew your combustion chamber size and piston specs, someone could tell you what your compression actually is.
I will be curious to hear back from you if the other GPS reads the same numbers as the first one. If it does, your boat will out run about 90% of the other jet boats you will run into here in Northern California. (If so, that's a good thing). :D

[a catered life]

Rich please drink some coffee before you begin to type so early in the morning :D
Congrats on the maiden voyage Gunny. :cool:
hey cale that is after his coffee :cry:

[396_WAYS_TO_SPIT]

12.5-1 on pump gas is MURDER to an engine! Alot of guys try to run pump gas on a 10.5-1 motor and kill parts. You need to be running avgas or race fuel PERIOD!! 89mph is haulin a$$ in a vee bottom hull. Can you take some pics of the set up (ie, pump, bottom, motor, etc) and post them for us??? I am curious to see what your setup contains. Also, i would use the gps in your car or truck to see if its remotely colse to the speedo. Let us know. We are all here to help you;)
396

[Gunny]

Well guys i took the new Jet back out on the Delta today. Wasn't the best of days, kinda cool but no rain just looked like it wanted to real bad. Some of the comments here about this 12.5 motor and pump gas had me a little worried. I did a little checking came up with an ingenious way of taking a look at the piston tops, without tearing the motor down and built the damndest Rube Goldberg device that has ever been put on a Jet Boat in the history of Jet Boats. I also took some different fuels with me. The boat had a 1/4 tank of 91 octane in it, i stopped at Reed Hillview and bought 10 gals of 100 octane AV Gas, this is unleaded fuel but it is supposed to be true 100 octane. I also went by Speed Merchant and bought a 5 gal can of 105 Octane fuel as well, then a couple of cans of lucas Octane booster and I am all set.
First a disclaimer to a few of you guys. 396 Ways I appreciate your comments as I do everyones. You make reference to "My" setup. It ain't my setup, I bought this boat the way it is last Saturday and this is my first Jet Boat i really wouldn't know the difference in any setup if it bit me on the butt. This speed thing as well guys, I personally take no pride what so ever in how fast this boat "IS" or ISN'T" because I had apsolutly nothing al all to do with that. i bought this boat if it indeed turns out to be fast or faster than most I had not one damn thing to do with that. I just got lucky or unlucky and time will tell. Now if I had done the setup and built this Motor and the fruits of those labours made it fast then I would take a great deal of the credit, however as things are I simply can't.
The Rube Goldberg thing: Sense "one" of the ways to tell if a motor is detonating is that dreaded pinging, and in this jet with it's wet headers there is no damn way in hell to hear anything much less pinging I thought i would remove the noise factor. I rigged up the damndest thing you ever saw. it was two B & M baffled mufflers rigged to run through one Cummings Diesel muffler. All held together for one real hard power run with muffler clamps, duck tape bailing wire, a little spit and an a-frame bolted to the back of the heads accessories boss to hold all of this crap up and together. Plan was to quiet down the motor at full throttle so that I could Maybe hear if it pinged. It was a hell of a lot of work, and it damn sure did quieten things down a lot. looked damn funny as well. With the 91 Octane pump gas there was no pinging that I could hear at any throttle position from right off of idle to wide open. I made this run twice before i took that contraptions off of my boat forever.
The ingenious way of looking at those pistons was I have a buddy who is a Gunsmith i borrowed his flexable shaft bore scope, pulled the plugs stuck it down the hole and looked, as far as i could to see what pistons where in there for real. This was real cool, i could not see a lot as its damn dark in there and a bore scope does not provide any light. but i was able to rig a plexe rod i bought at tap plastics to act kinda like a fiber optic kind of deal and was able to see that these pistons are in fact "Flat Top Pistons" They also are marked .060. Now while I was told and shown a reciept for JE 12.5 to 1 pistons, I do not believe that 12.5 to 1's would be flat. Someone correct me if my thinking is flawed there.
On to the test and speed run of sorts. the first time out this boat ran 89 MPH. This time out i went over to Fishermans Cut right off of the False River. This is a long perfectly straight channel with very little or no boat traffic even in nice weather. Today I had the place all to myself. I had two hand held GPS units. One was my own Lawrance and the other a borrowed hand held Gorman. I could not hold both of them and steer the boat so i rigged one up on the dash next to the speedo where i could at least see it. The first 4 runs up and down the channel on the 91 octane where: 78--79--63--74. Dont know about that 63 MPH run must have been the driver, but hell it felt the same as the others. I then ran around and emptyed out most of the 1/4 tank. Put in the 5 gal can of Speed Merchant 105 octane stuff 4 runs with this where: 72---69----76---68. Then I tried the 100 octane AV Gas 4 runs with it where 78--79--78---77. I also tried the octane boosters and they didn't show me anything.
This was a very UNscientific test. Just one big ass hole running up and down the channel scaring the hell outta the gulls and fish and laughing his ass off and having a ball. Didn't prove or disprove much of anything but was a hell of a lot of fun. I did not even get close to that 89 mph speed of the first day, my thinking there is that maybe what I was seeing on the GPS was 69 and not 89 and those damn letters and numbers are so damn small I got mixed up. Hell guys Marines arn't supposed to be smart just willing.
Looks like bad weather for the next week or so, so the Jet will sadly have to sit and I will use the big boat for my thearpy, but on that first half assed nice day ( and that means not too much rain) listen real good and you will be able to hear me laughing.
Gunny

[Squirtin Thunder]

Those are still good #s and you also found out with the tune-up it likes the 100octav gas. So it sounds like it was a good day for you. But then again any day on the water is a great day right ???

[DCBob]

Hey Gunny, where do you keep your big boat? We have a small piece of property on Fisherman's cut and go out there a lot!

[78Anthonyjet]

Gunny, not to jack your thread, but you might want to come up to Shasta in June, should be a good time.
You have some pretty good numbers, my old jet got to about 50ish and was out of peddle, new one runs about mid 60's.
See ya on the water,
Norm

[Gunny]

DC, I keep the Cruiser at a Marina on the San Joaquin River right across from Antioch (sp) Eddo's Marina. Nice real layed back place. They have a pretty big storage yard there as well and for now I am also keeping my Bass Boat and Motor Home there as well, the Jet Boat that one goes home with me.
78Anthonyjet, go ahead jack away thats cool, as long as anyone has something to say. June sounds real good and i will make plans to be there, but damn thats a long way aways. The numbers do seem pretty good, however I take no credit what so ever for them I'm just the big dummy pushing down on that foot shaped pedal, takes no skill on my part.
Gunny

[78Anthonyjet]

The numbers do seem pretty good, however I take no credit what so ever for them I'm just the big dummy pushing down on that foot shaped pedal, takes no skill on my part.
Gunny, that is the same for me, didn't build it, but drive the hell out of it. It's yours, run it till it breaks, fix it and do it all again.

[78Anthonyjet]

http://www.***boat.com/image_center/data/520/3116IMG_8090r.JPG
Heres what it looks like running.

[Squirtin Thunder]

There is also the Classic Boat Beach Bash that Hackjob and Flatbroke put on every year at the Avi Casino in Laughlin NV on the Colorado River.
www.classicboatbeachbash.com

[Den Isle]

Hey Gunny!
100LL avgas is anything but unleaded, it is low lead as compared to the 120/130 avgas it replaced.
It is very hygroscopic, which is egg head for absorbs water like a sponge.
It will also foul out an O2 sensor if you use it on fuel injection or Lambda meter.
If you plan on using avgas be very carefull of corrosion in your fuel system, as the avgas absorbs water, any dissimilar metal in the system starts to get galvanic corrosion. Gets ugly fast.
Aircraft recip. engines generally need to clean the sparkplugs every 50 hours or so to prevent lead fouling.
Have fun!
Regards, Chris

[wsuwrhr]

OK I'll bite.
Nuetral in my jet is somewhere between forward and reverse.
Works pretty good for me.
Brian
I usually launch and recover with the boat off anyway. I don't liek sucking shit into my pump.

[396_WAYS_TO_SPIT]

Hey gunny, I was referring to the setup that you currently own. My bad if it came across to you the wrong way. Like I said before, take some pics so we have refrence to help you with. A picture has a 1000 words to go with it;) The numbers that you are running are very good ones;) Let us know if you need any q's answered. Oh and putting her on the trailer takes practice;) It comes with time;)
396

[Gunny]

Chris,
While there is not a chance in hell for me to understand all you said, you are correct the AvGas was Low Lead and not No Lead. So I stand corrected--- Bad Gunny, Bad Gunny!!!!
Brian,
I undersatnd about the shit sucking ( as it pertains to the jet pump that is ). But I gotta tell you something that water temp in the Delta was 51 degrees where I launched the boat "Today". There was no way in hell i wanted to get out and wade in that stuff, and then scoot around the lake at speed-- No Way!! Its bad enough having to get in the water when i load the boat onto the trailer, but i do this by myself like in all alone and I'll be damn if i can figure a way to not get wet. I drive the boat onto the trailer just fine but then I have to get out of the boat and there is simple no way for me to do it. I walk with a cane right now, and i hope that all of this boat stuff will get me off of that damn cane soon, so sometimes just getting into and out of the boat is a struggle. That and some of these guys at the boat ramp i gotta tell you. I thought that for sure and for certain that today i was going to have to give this one ass-hole a tune up. Boy needed an attitude adjustment in the worst way, and he fuc&ed with the right guy to get one. I was tired to the bone after spending most of the morning and some of the afternoon on the water. What i didn't need was this lame ass guy giving me grief for being slow, hell man there are at least a dozen spots on the ramp and he and I where the only two loading up. Pick another spot ass-hole!! Sorry guys I'm ranting not cool.
Gunny

[Gunny]

Hey 396,
Man I did not mean it that way, not at all. What I did mean was I really do apprciate all you and everyone has to say. When it comes to these boats i am a dump ass, I simply don't have a frame of experiance to call on. I will ask questions and I am always grateful for an answer. As a matter of fact i have read a lot of your posts and I believe that you do actually know what you are talking about. Now if you want to talk about being a Marine maybe i can speak to that some after 30 years in the Corps, but boats NO man i simply do not know. But i am willing to learn!!! Hope I'm not to damn old to do that, as this Jet Boat thing is some kind of cool thing.
Gunny