Gw invader with Johnson Motor

[carbineone]

Hey everybody,this is a great site and has been very helpful so far.Only been here a day but it has helped me out alot.I have another question and I am sure more later.I will include a pic of my little 10 foot invader so you know what I am working on.I bought this little boat about 15 years ago on a farm auction for 12.00.I got the 28HP Johnson motor,controls and wiring for free.So really the only money I am into it is the trailer for 175.00 and a 100.00 for the new seats.The 28HP is really not my first choice.They are rated up to 55HP but I am hoping to atleast get 30MPH out of it with the 28 but maybe I am dreaming.So my questions are it is a short shaft boat and my cavitation plate sits about 1 1/2 inches below the bottom of the boat.Hopefully you can see it in the pic.Should I raise it maybe even with the transom bottom.I can put a spacer in to do so but about a 1 1/2 inches is all I can get it raised.Also do you guys think the 28HP Johnson will move this little boat decent.I am hoping to get atleast the 30MPH out of it.I am going to have some questions on painting the topside also later.Thanks

 

[mikesea]

Re: Gw invader with Johnson Motor

what i think is,sell it to me,kiddin,thats a fun boat,it will porpose a lot,you can try jacking it up the 11/2,i knew 2 gw's that had 33 hp's on them,surely 30 mph,as for paint,i'd use awlgrip,you can roll it out,follow the instructions,u can also look under the restoration forum on iboats,

 

[carbineone]

Re: Gw invader with Johnson Motor

Thanks,are you saying it will porpose because the motor has lack of power or because it is sitting too low currently,You think it will porpose if its raised up.I did see a guy with a old 18HP Johnson on his GW and he claimed he could get 25MPH out of it..Saw a video but could not tell just how it handled for sure..Yes I should sell it to you,LOL..But I have had it like I said for about 15 years and its just been sitting till now and have decided to get it going,some for me but mostly for my 13 year old son..These only weigh around 250 lbs.I sure would like to have atleast a 40HP but cannot afford one and short shafts are very hard to find..Have looked for about 4 months now and did not find anything I could afford so am going to try this old Johnson I had anyway and see what it will do...Maybe I can get lucky and find a bigger HP over the next winter if this one is way under powered...

 

[tashasdaddy]

Re: Gw invader with Johnson Motor

OK what you have is an older short shaft motor, they do set a little deeper, due to the cooling water pickup. you have a 15inch transon. the older motor measured from transom clamp to AV Plate 17 1/2 inch. you might raise it 3/4 to 1 inch at most.

if i were putting a 13 year old son in it. i would keep the 28 on it. that is plenty of power for him, and will get close if not to 30 mph.

porpoising, can be helped by moving the adjustable tilt pin, on the transom bracket, or adding more load to the bow.

i envy you with the GW.

 

[mikesea]

Re: Gw invader with Johnson Motor

as Tash said,you might fix the porpose with the tilt pin,BUT ,back in the 60's I knew 3 guys with GW's and I THINK they liked the porposing,ya gotta remember ,it was a time when the 110 MERC was the top dog,so that lil invader was a speed demon beyond any comparision at the time,most lil boats were still wood,the bounce added to the picture.You can add trim tabs.I have often looked on the NET for a GW OR the old GLASPAR G3.With the 28,the boat will be fast and squirley for a young kid (especially no experience.My buds flipp[ed OFTEN enough,put a safty kill on it .Most 'shorty "lower units were fabricated by racers ,I belive there were a few units made for special run boats,if you can find one ,your lucky.At this point ,run as is,you can play a bit with the tilt pin and since your eng is a hand screw connect,you can shim under the mounting clamp as you want.I would LOVE to try that boat with a 3cyl OMC and a short lower designed for the SST racing circut.Likely I would end up swimming.I know there are clubs for old boats ,look on the net and try to join.That is my desire SOMEDAY after the woman says my honey do's are over.NO NEEED TO COMMENT GUYS.carbineone,you have a classic,I think u know it ,enjoy it.PLEASE watch out for the young guy.S**t happens

 

[carbineone]

Re: Gw invader with Johnson Motor

Thanks,well the little fella will not be operating it alone.I do not even think he can here till hes 14 maybe 16..I will be supervising him atleast this summer for sure and will ride with him,By the end of the year he should be pretty good with it..About all we can do is run it and see and will not raise the motor more than a inch you said to keep the pump pickup in the water.Did they actually put a 110HP on these back in the day?Or am I just misinterpreting something.I cannot imagine someone putting that big of a motor on one.I have seen one with a 60 Merc though.I am not wanting to die just have some decent power and fun.I actually have not been able to find alot of info on these little boats since I have had it.

 

[tashasdaddy]

Re: Gw invader with Johnson Motor

i do not think the transom would stay above water with a 110 on it.

 

[chrissunsation]

Re: Gw invader with Johnson Motor

I had one of these that started out with an old evinrude 40hp (Space Helmet) and later installed a inline merc 50 hp. A group of my dads friends leased the molds and had a dozen of them built up here in Algonac, MI. With having so many around it was a major competion to have the best one. We were seeing mid 40's out of ours. The trick to these is to install a jack plate, it really helped minimize the porposing, it didn't eliminate it but it did help. The other thing about these is that they turn like crap so I installed a skeg off of an old water ski and boy did that make a difference. I really miss that boat and I would love to find another one so if anyone has one let me know. Good luck with your project and feel free to contact me with any questions.

Keep us posted on your progress

 

[carbineone]

Re: Gw invader with Johnson Motor

Hey Chris,well I will keep you in mind if I for some reason do not like mine..About these water ski skegs.I know what they are but where exactly did you mount them on the boat?Just one or two or what?I really do not know what to expect from this little boat.Like I said I bought this 15 years ago and am just now going to try to use it..I need to get it painted yet,do a little more wiring and install a bilge pump and get the lights all working.I am hoping it will be a fun boat.I am getting anxious for spring to get here and it will be quite a while before theres open water here in Nebraska to give it a test run.It has just been a miserable winter as all know I am sure..I am sure I will have some questions and will contact you.I do not find a lot of people that have or had one of these little GWs.Thanks...Bruce

 

[carbineone]

Re: Gw invader with Johnson Motor

Chris,so where did you mount the waterski skegs?One in the middle or one on each outer side?Heres a couple pics.Almost getting close to being done.Have a few little minor details to finish but we are getting anxious to try it out this spring...Bruce

 

[mikesea]

Re: Gw invader with Johnson Motor

i do not think the transom would stay above water with a 110 on it

R U trying to B funny,or did my inability to be clear screw it up.I was trying to say,anyone with a 40 on a lil boat had something fast,a 110 ,today is small compared to the 350 hp's,that leaves a 40 hp,today,like a 10 hp back then,OR SOMETHING LIKE THAT.
anyway,enjoy the invader,wish I had one

 

[carbineone]

Re: Gw invader with Johnson Motor

Thanks Mike.I guess I am confused what a 110 Merc is.I looked it up and I thought it was a 10HP when I did.Maybe 110 is a model designation for a 10 HP Mercury in the old days? Not real familiar with stuff so go easy on me and I am really not as stupid as I sound.LOL...Mine is rated up to 55HP on the ID tag is all I know for sure...Bruce

 

[mikesea]

Re: Gw invader with Johnson Motor

oh man,Im talking about a one hundred and ten horsepower mercury .Back in the 60's exact year I cant recall.But the 110 merc was considered the top dog in my town,I lived in a small town and a guy had a 110 on a tri hull,that boat looked like it was flying back then,the guys with the lil invaders ,with 33 and 40 hp gave the guy in the 110 a good run.