scubapro820 said:
https://s1127.photobucket.com/albums/l628/scubapro820/?action=view¤t=VIDEO0013.mp4 very poor video but it didnt sink or blow up!
I watched the video, with my head tilted to the right....LOL Other than the camera being sideways, good video! Good enough that I was able to hear and see enough to help assess a few things, at least.
As far as no sinking or blowing up....well, that's 2 major things that did not go wrong, and that's always a good thing.
problems
1: Cap flew off the extra water outlet,
2:spark plug insulator broke Not sure why, Was a slow trip home
3: minor leaks
4: pitch on the impeller is not correct the engine easily over revvs
5: HOLY GOD ITS LOUD " thank you hearing protection"
6: it idles quite high 3-4,500rpm
7: top speed with 3 ppl 575lbs 32mph
1. Extra water outlet: Are you referring to the one on the pump?
I noticed the stream of water shooting way off to the starboard side..... this is from the fitting on the top right side on your jet pump that would normally hook to the 'enema' fitting on the Yamaha jet skis (that silly little stream of water they have that shoots straight up) Know what I did with that fitting on my boat? I ran it to a quick connect deck fitting, for a wash down hose connection.
Yeah, you have to be running at speed for it to have any pressure, but it works pretty good. I can run along, and use my little coil hose with the spray nozzle, and rinse mud and junk off the deck.
2. Broken spark plug insulator: Only a couple of things cause this....accidentally dropping a plug, or something striking the plug, both of which will crack the insulator. In the process of taking the plugs out, while blowing water out, it is possible you dropped one, or possibly banged an adjacent plug with the wrench while removing one of the plugs. NEVER re-use a dropped/impacted plug...it ain't worth the potential engine damage that can result.
3. Minor leaks: Are the leaks from hoses and fittings, or hull leaks? Either way, they're minor, and I'm sure you'll get those addressed.
4: Impeller pitch: If you don't think the pitch is right, you can have the prop re-pitched. Look up "Impros Impeller Repair" They can build up worn down props, sharpen them, and they can also re-pitch them to whatever you want. You should talk to one of the techs, and give them your info, such as boat weight, type of engine, type of pump, and they can help figure out what pitch will help the boat run its best. With my XL1200 pump, I've run a Solas X prop in 14.5/17, had good results with that. Right now, I'm running a Solas Concord prop in 13/19 pitch.
5: LOUD....yep, that's one thing about Tigersharks, they are loud as hell. You might consider building a platform on your transom like I did with my boat. When I had the TS engine, this platform helped to quiet it down a LOT. And then when I put the 4 stroke in there, from the shore, you don't even hear the boat unless it's moving away from you.
Also, you don't have a cowling. You should consider fabricating one, and lining the inside of it, and the engine well, with some egg crate foam. You'd be amazed what a difference that will make. Also it will protect your engine from the elements, or being damaged if you get swamped.
6. High Idle: Make sure your idle stop screw on the front carb is properly adjusted, and make sure that your throttle cable has some slack, there should be a small amount of travel in the throttle lever before you see the throttle linkage move. The idle should be set out of the water, at about 1750 RPM. In the water, with a load on the prop, it'll be about 1100 RPM. Don't set the idle in the water, because it will idle too high out of the water, when you take the load off the prop.
7. Top speed 32 MPH. Is that a GPS'ed speed, or according to a speedometer? Also, remember that the pilothouse on your boat is going to create a lot of wind drag. I have a T-top that bolts onto my jetboat for wintertime use, when I have it on there, I lose a few MPH's because of the wind drag. Also, re-pitching the prop may help. You want the impeller pitch to allow the engine to operate at its max RPM, but don't over-pitch it too high, or the engine will not reach full RPM, and it will be under a much heavier load. Under-pitching has the opposite effect....15 MPH at 7 grand, LOL Again, the folks at Impros should be able to help you out.
whats not wrong
1: steering
2: Trim
3: electronics
4: bilge/ guages
5: no cavitation!
I figured the steering would be right when I saw the photos of the cable installed.
Having working trim is a good thing, too....you should notice the boat lifting at about the halfway point in the trim, and it should pick up a few MPH's. With the trim down, the steering should be very quick and responsive, like being able to spin a 180 in the boat's own length.
Working electronics and gauges is also a good thing. I always seem to have problems in this area when I build a boat.....everything else works good, but it's always something fruity going on with a gauge, usually minor, like a ground wire.
And finally, no cavitation is a great thing, because this is the most common problem with jetboat conversions to johnboats, it's worse on flat bottom boats like mine. Yours being a V-hull probably helps a lot. Since you don't have issues with cavitation, that means you don't need a top-loader grate. And if you don't have a top loader grate, that means you can convert your existing grate into a stomp grate, for clearing weeds. (check out the photos of mine for a general idea)
Like with many projects, it's a matter of trial and error, and doing some fine-tuning. Although I built my jetboat in 2005, I tweaked, improved, and fine tuned things for a couple of years, until I had the boat just about the way I wanted it.
Then, when I installed the 4 stroke, I had to re-configure some things, but once it was installed, it was a done deal.
