PDA

View Full Version : question about 15' tunnell



wawa c
08-31-2013, 05:16 PM
i have a 15' gw invader tunnel hull boat with a 140 johnson. when planed off no matter what the trim setting is it shoots water straight up each side of the motor and into the splash well. i mean a lot of water gets into the boat. is the motor mounted too low on the transom? or what is going on here? i will try to post pictures of the setup as soon as i can. but right now i am on a tablet. i've seen a question of this nature on this site before but can't find the post or if there were any solutions. any help is appreciated thanks

fs5
09-01-2013, 03:44 AM
from my experience mate,water usualy sprays up the way your saying from a motor mounted to high.
you still getting water pumpin out the pisser?
are you runnin tabs,or a dolphin fin on the motor?

wawa c
09-01-2013, 05:28 AM
thanks for the reply. no dolphin or trim tabs. pees just fine. i don't think it could be mounted too high as the prop shaft is 3" below the sponsons, and the cavitation plate is 4" below the tunnel

zul8tr
09-01-2013, 06:00 AM
Show us a side view pic of the transom and motor out of water and any other pics you have.

wawa c
09-02-2013, 06:24 AM
here's pics5484554846

zul8tr
09-02-2013, 07:09 AM
Hard to see in the photo but has the forward edge of the lower anti cav plate been trimmed away? Has the forward part of the upper deflecter plate been trimmed? The upper deflector plate is there to prevent (or reduce ) the upward climb of water spray from the forward edge of the gear case below the anti cav plate and water rise from the rear planning surface from a non tunnel hull. Somewhat unlikely scenario but the tunnel pads do not look that wide at the rear and even though there is a small positive dihedral angle on the pad planning surface that would spray water out, the narrow surface could spray alot of water toward the engine tower and then vertically up? Plus your engine looks kicked out that would force the tunnels deeper at the rear and that contributes to the side spray.
Next time out take have a rider take a video (or pic) of the water action at the rear.

wawa c
09-02-2013, 07:24 AM
it doesn't look like anything has been trimmed off the plates. i took this motor off an 19' mark twain tri hull boat that was just used as a family runabout. hard to believe anybody messed with it. the kick out on the motor is just where i sat the engine back down with the power trim for the pictures, it goes further down than that. i ran it at different angles didn't seem to make much difference in the spray. does the height of the setup look ok? i could raise the motor maybe another 2-3 inches with the mounting holes on the swivel bracket. i will try to get pictures of it in action next weekend.

zul8tr
09-02-2013, 09:40 AM
The height looks OK for now, run it and get some pics or video of the water as it comes off the hull and as it contacts the motor and rises up.

Popa Sam
09-05-2013, 04:47 PM
Appears you about 3" too deep. When you raise the motor enough to stop the transom over wash you will need a different prop.

Riverrat001
09-05-2013, 06:10 PM
I agree with popa sam motor needs to go up at least 3 inches. I've never had a problem with water coming over the transom from being to high

wawa c
09-09-2013, 12:45 PM
thanks guys. i raised the motor about 2" thats all icould without drilling new holes in my new transom. splash from the motor going straight up and into the splash well went away. thats good. whats bad is now i get cavitation just as the boat is planing off or when throttle is really jumped on. it acts like a spun hub because even when i back off or feather the throttle it still spins, tried a different prop that was in my garage seemed even worse. the first prop is a stock 131/2 x 17 aluminum i had run this prop on this motor with my 18' aluminum fish boat with no problems, the second prop was given to me with a box of other parts condition unknown. same size and pitch. i know i need something different prop wise, what would you all suggest? heres a side view of the rig.54920

sabine river killer
09-09-2013, 02:00 PM
now get a good prop and keep going up

Jimboat
09-14-2013, 02:12 PM
Appears you about 3" too deep. When you raise the motor enough to stop the transom over wash you will need a different prop.
Yup, for sure! Sounds like you're much too low. Raise motor, make sure you're still getting water (get a pressure gage). Test for new surfacing props.

Detroit Whitey
09-23-2013, 07:53 PM
Had that boat might even be that one who knows but what I do know is you have to go way up get a jackplate and block off the two top holes on your water pick up on Gearcase or you'll over heat. That's a t150 gw invader I had a 235 on one and it was a great ride I think I remember the guys name who built it gray wooldridge or something like that. did that boat have space invader black and yellow stripes on the deck?

pdt
09-24-2013, 04:03 AM
what sort of speed would this boat do with that 140hp Johnson on the back / and is this a crossflow 140hp circa 1977/78 ?
looks like a pretty mean and sleek boat.
are these ok in the rough stuff or purely a smooth water boat i.e lakes and rivers it looks pretty nice

wawa c
09-24-2013, 05:51 PM
from my info this boat came from southern indiana. i bought it near indianapolis. these boats were made by gary wooldrige (spelling?) in central indiana. i'm told gary hada cottage on syracuse lake 2 doors down from were i now live. any way this boat was gold with silver metal flake and equiped with twin 105 chryslers pipes and speedy lowers. early 70's. think i shoulda used a short shaft motor, as i have raised this motor at least 2" and it needs to go up more. some one please give me an idea on what type of prop i need. any input or leads to a prop would be appreciated. oh yeah the motor is a 1978 don't know if thats good or bad. just stuff i had laying around.

pdt
09-25-2013, 12:26 PM
That 140 crossflow v4 is a pretty good engine when going right. very powerful;l for just 1600cc engine.
still plenty of them around for spare parts as well.

They are also so much lighter than the v4 engines nowdays. only around 320 pounds with power trim !!!!

Detroit Whitey
09-26-2013, 12:26 PM
If you gonna run the fishing lower unit i would look for a stainless prop from omc like a srx or maybe one of ther bass boat props like a raker or shooter. I ran mine with a 27 omc cleaver and didn't have it set up very well I could see 80's bit after that you were in the danger zone.thats why I sold mine wanted to blow over over easy fun boat thou!!!

thornl01
09-28-2013, 05:53 AM
you have got to get a jack plate ( see Carolina jack plate.com) BEST PRICES & simple plates. No new holes to drill, plate mounts to existing holes.

start looking in prop section here and on ebay for older style cleaver props. I would be a little leary of a chopper style prop as these have a lot of bow lift & I have heard that these invaders like to get a little kitey.

Props from the SST-60 guys will be your best bet. 12-13" x 23,25,27" pitch.

Contact Ron Hill, he may have some 27,s w/13 spline.

play fast roger
11-06-2013, 09:32 PM
I agree with popa sam motor needs to go up at least 3 inches. I've never had a problem with water coming over the transom from being to high

any one done this