hello all, im new to the site but have been in the hobbie for like 18 years. cars trucks boats planes helicopters ive had a ton. anyway the picture in my profile is a boat that i custom made 2 years ago, no plans, no molds,just a pile of wood i bought at the local hobbie shop. the build went great, took me some time, but what could you expect. i used a brand new thunder tiger .21 pro outboard and love the engine. well the boat go's good but i have one issue with it. when it gets up on plane the boat will start to bounce the nose and eventually jump completely out of the water, seems as though it is over powered. i tried trimming the engine down to try and hold the nose down,didnt help. i ended up putting some weight in the bottom of the boat. helped a ton. now it only does it at high speeds, and will start off as a slight bow hop and end up jumping out of the water again.. now after all the babbaling the main question here, would trim tabs stop the bouncing at high speeds. its not chime walking, im getting a bow bounce. any info would be appriciated. http://www.modelgasboats.com/media/kunena/attachments/legacy/images/3215_ebay_040_jpg252df2994484d82247e504523102a9b0
http://www.modelgasboats.com/media/kunena/attachments/legacy/images/3216_AC_CUSTOM_BOAT_001_jpg4c6e688901945f97bc11dec6f3a62cb3
http://www.modelgasboats.com/media/kunena/attachments/legacy/images/3218_AC_CUSTOM_BOAT_007_jpg1048d79cfa13eb2a79caca4c3827ad48
http://www.modelgasboats.com/media/kunena/attachments/legacy/images/3220_ebay_029_jpgf575807388e483b1c9c7a448a4930146

Trim tabs would probably help. I would start by checking the balance point of the hull. Not really sure what it should be, but I would think somewhere between 30-35% forward of transom. To accomplish this measure your hull from transom to tip of vee, and multiply this number by 0.30 to 0.35. Take that number and measure from transom and mark the hull. Add or remove weight from the bow to get the boat to balance at this point. Typically you do this with the tank half full of fuel.

Ex: assuming the hull were 30"long overall. 30"x 0.35 = 10.5". The boat should therefore balance at 10.5" forward of transom. Play with this to see if it helps. If you still can't get it to run satisfactory try adding trim tabs. On outboard hulls, a set of fairly long tabs usually works better, say 2-3" long by about 1.5-2" wide.

marc, excellent information. is this how all outboards should be balanced? does the weight of the engine matter? i found a set of adjustable trim tabs on ebay, that are 30mm wide by 40mm long. do you think this would be sufficent? im kinda limited on room obviuosly cause the outboard turns left to right so much.

The engine counts in the equation for sure. I am basing my suggestions on the fact that it's a V hull, not on the fact that it does or doesn't have an outboard engine. I could be wrong, but I think 30-35% should get you there...I would start at 30% and work my way up. A while back I built an outboard powered V hull also, and I think it balanced at about 31-32%...ran pretty good. No tabs.

im on it. this will be the first thing i do. i still need to wait for the weather to break anyway so i have time to mess around with the percentages. i know when i built the boat i was going to use a inboard .21 but the outboard came at a good price new in the box. the boat only weighed 2 pounds and the engine weighs 1.55 pounds so you could imagine when i put it on the transom and put it in the water the thing stood like straight up.