Hey all, I've been racking my brain trying to figure out what the deal is with my miss elams .15 engine. It starts great and out of the water runs beautifully. When I get on the throttle it snaps quick and strong. It puts out a nice little ploom of bluish/white smoke. The problem is when I toss it in the water it runs sluggish for anywhere between 15 to 30 seconds and dies no matter how much throttle I give it. I've ran it rich, lean and everywhere between. I've had approx ten tanks of gas through it and I took my time and broke the engine in per the instructions that came with the boat.

Possible culprits?: The engine seemed to have ran okay before I installed a twisted liquid y535 two blade prop. I also added a fuel filter and extended the fuel line a little. I can't see how any of these would affect the engines performance. Just thought i'd add that in so if someone on here tries to take a stab of whats going on here.

Please help, I like this little boat but it's tiring out my retrieval boat and it's definatly trying my patients. This boat is one sputter away from a target at the local gun range.

Out of the water the engine should be rich, and sluggish to respond from an idle. Once in the water it leans up. The prop change will probably change the engines need for fuel. Or it could be the prop is just too big for the engine to turn. Been there tried that with my boat.

sounds like too much prop to me...i had the same problem a few times..

Have you tried going back to last good running prop and no fuel filter? I would do that and add each in and see how it goes from there if the filter works with your set up then try your prop. If the boat performs with the filter then its probably your prop, and vise-versa. Also make sure your pressure lines are good (no leaks and the fuel line is the same ,no leaks). Ya gotta do the systematic trial and error. Hope this helps a little


Paul

Thanks guys, noted. I'll give all the suggestions a try.

Are you launching the boat with a good toss to get it up on plane?

Ryan

RaysonCraft and mtruex are on the right track. If you can pop the throttle and the engine accelerates cleanly with the boat out of the water, you are to lean. The engine should stutter when accelerated without a load. Unless you have contaminated your fuel with solids and the filter is partially plugged I doubt that the filter is contributing to the problem. To much prop will load the engine and prevent acceleration also. Did you just grab any old prop or did you pay attention to the diameter and pitch to be sure the engine can handle the load? My guess is that the wimpy engines they put in RTR boats can't take much prop. And excuse me for correcting you but we do not run gas. We run a Nitro methane, methanol and oil mixture we call fuel. Two entirely different combustables.

check 2 make sure that your head is not leaking water. This is best done static with some sort of water pump.

RaysonCraft and mtruex are right the y535 is too much prop for the .15 to handle. Alot of people say thats a good prop for the proboats but its not, unless your running a .18 engine like the formula boat has.

I would recommend a M435 prop for your proboat, thats a awesome prop and works well with the .15. I race the proboats hydros in my local area and have tried just about every prop out there, and I always come back to the m435/3 blade

I run the same prop and no propblemo..(lol)...bottom line,you are tooo lean ,start out at 3 1/2 turns out and work your way in 1/8 at a time.......voila