Dumas Hot Shot 3.5?

[crispy]

I got this hull from my boss at work and had to put a bunch on $$$ into it to get it water ready. I've never had a tunnel hull and thought it would be fun. It has a K&B 3.5 in good running order with the self tilting mount.



The steering cables are tight and there is virtually no slop of the engine side to side. The servo wheel has not been stripped out.

Ive tried to raise and lower the engine and even tried a different engine mount that allowed me to take the tilt out of the engine...actually point the prop down.

 

[julianconde]

prop and engine hieght,angle of the prop thats your problem... change props use a X438

 

[dave roach]

That is the first boat that I built 24 years ago and I still have it.Does your boat have a turn fin on it,On the right sponson under neath. If it doesn't and that is your problem to your turning problem.See if I can get some pictures of mine to show you the turn fin.

Dave Roach

 

[crispy]

prop and engine hieght,angle of the prop thats your problem... change props use a X438

What height and angle is a good start point?

I have the height set so that when the hull is flat on the bench, the center of the prop is level with the top of the bench.

the transom has a set angle, how do I change that? I put the stock mount back on because the adjustable one I used made no difference.

What's the difference between the x440 and the x438? Be kind.....I'm a NOOB. LOL

That is the first boat that I built 24 years ago and I still have it.Does your boat have a turn fin on it,On the right sponson under neath. If it doesn't and that is your problem to your turning problem.See if I can get some pictures of mine to show you the turn fin.

Dave Roach

No turn fin. It is the fiberglass hull, how would I mount the turn fin?

When I first got the boat together, it seemed to run good. (black carb and x440 prop) but it was slow. I got the gold carb and that's when the problems started. Have a look through my other videos, there is a prop cavitation video with the stock prop.

 

[norm j]

here are some things to consider, make shure your steering rate is at low setting,move your steering links close as poss. to the inside of the arm,on the servo

also make shure you have a strong enough servo,for steering,i have one of those boats,as well they are kinda touchie to drive,be smooth on the steering

controls,you might want to consider installing some trim tabs on rear area on the sponsons too

good luck!

norm j

 

[norm j]

i noticed the auto tilt feature on the mount,cool idea!,but with that boat,its gonna hook up as soon as the nose comes down,try to run it without the

adjustible mount and see what happens, if you have watched to real sst style boats, they drive in a simular manner,bow comes down and then

sharp turn,try to slow down into the turn let the bow come down then apply steering,that about all i could say right now

norm j

 

[Kez]

I still have three of these Hot Shots after some 25 years.

It is counter intuitiative but having the CG too far back will cause hooking. Try moving the CG forward. Add wt if you have to.

The HS sponsons have a "keel" (for lack of a better word) about 3/16" at the inner edge. If you place your boat on a bench, that would elevate the boat by about 1/8. Keep that in mind when you set the prop depth.

 

[crispy]

i noticed the auto tilt feature on the mount,cool idea!,but with that boat,its gonna hook up as soon as the nose comes down,try to run it without the

adjustible mount and see what happens, if you have watched to real sst style boats, they drive in a simular manner,bow comes down and then

sharp turn,try to slow down into the turn let the bow come down then apply steering,that about all i could say right now

norm j

I did run with a prather mount and it didn't help ,so I put the tilt mount back on. The steering servo is a Hi-tec hs-645mg with a wheel. the steering rate is really low (around 25%) Side to side throw at the prop is about 1" either direction.

 

[moparbarn]

motor height looks low to me. try raising it up to even with the bottom of the sponsons ( not the little inner keel), maybe 1/8" above. the lower the motor, the more the nose is down, that will cause hooking. the prop will try to run about 1/2 way in the water, so as you raise the motor, the stern goes down, & the bow comes up.

 

[PhillyDees]

Try lowering the engine down. This will help. Go all the way down and see if it helps. If it does then slowly start moving it up till it starts doing it again