HOW FAST SHOULD I BE GOING

"About how fast should my boat

"About how fast should my boat be doing. I have a 1974 glastron aq130 with a 15 17 prop, tri hull speedo says fifty only does 20? I would think it would at least hit forty , All i need is an estimate, if someone as has this boat , tell me what yours tops out at. Just curious"

"Here is some math for you to

"Here is some math for you to ponder about.

If you divide your engine RPM by 2.15 (outdrive gear ratio) you get your prop shaft RPM. If you multiply the prop shaft RPM by the prop pitch in inches, then multiply the result by 60 x 2.54 and divide the result by 100 and then by 1852, you will have your theoretical speed in knots. Then, if you apply a propeller slip between 15% and 25%(that is, you deduct between 15% and 25% of the calculated speed value), you will have an idea of what your boat speed should be."

"What? sorry you lost me , not

"What? sorry you lost me , not a math kind of guy Just wondering if anyone had the same boat that they could tell me how fast theres did. because my boat boggs out, likes to turn one way, makes funny sound when turning and is taking on water some where. put too much $$$$ into it to turn back."

"Might be hard to find someone

"Might be hard to find someone with a truely identical boat. Maybe try to find someone with a similar setup. How long is your boat, how much does it weigh, engine type, drive leg, prop etc..."

"OK, I'll make it easy for

"OK, I'll make it easy for you. With a 17 " pitch prop you sould be doing a theoretical speed of 33 knots at 5100 RPM (max RPM for your engine). If you estimate the propeller slip between 15% and 25% you should be doing between 25 and 28 knots. Don't trust the speedo reading, use a GPS reading in an area free of currents.

If your engine boggs-out, check the timing and carb adjustment.

If the boat turns one way (I guess you mean it "pulls" to one side) then ajust the trim tab above the propeller. Again, check the volvo instructions.

If your outdrive makes a sound when turning, the outdrive u-joints may need replacement.

If you are taking water, that's another challenge, but make sure that the 6 nuts holding the transom shield in place are tight.

It takes awhile to get a boat perform the way you want, but patience will get you there. "

"thank you for all the info ,

"thank you for all the info , much appreciated Have just been fed up with it. Have tried to sync up carbs but Not sure , if they should have a vaccum advance on them ? or on the distrubutor , I should just bring it into a shop have them look at it. THANKS AGAIN"

"Marine distributors do not ha

"Marine distributors do not have vacuum advance.

To synchronize carbs properly, I strongly recommend that you use the Unisync vacuum gauge, which is inexpensive and effective. I also suggest that you get hold of the SELOC or Clymers repair manuals for your engine and follow the instructions regarding timing and adjusting carbs. Also, you can follow the instruction in the owners' manual for your engine, which you can download from the following link:

http://www.volvo.com/volvopenta/global/en-gb/marineengines/operators_manual/

Good luck."