Cobra 7.5M Owners - Compare Speeds

[boristhebold]

Hi, I recently put a laser 2 prop on my cobra 7.5M running a yamaha 200 2 stroke, while the acceleration and mid range have improved I dont seem to get any higher top end speed, in fact it may have dropped off slighly as I was getting about 44Knots of original prop now im struggling to get 41Knots - sea conditions slight.

What do other cobra owners get from there engine + prop mix and any suggestions as to best type of prop to use.

[boristhebold]

I bought a new prop like the original and have now found my lost knots. I guess with props it's difficult to beat the original spec. Lesson learnt.

[TangoTango]

I have a Verado 200, clean bottomed 7.55 and I get 42 knots max with 2 persons on board.

[Jizm]

Originally Posted by boristhebold

Hi, I recently put a laser 2 prop on my cobra 7.5M running a yamaha 200 2 stroke, while the acceleration and mid range have improved I dont seem to get any higher top end speed, in fact it may have dropped off slighly as I was getting about 44Knots of original prop now im struggling to get 41Knots - sea conditions slight.

What do other cobra owners get from there engine + prop mix and any suggestions as to best type of prop to use.

What revs were you getting?

[boristhebold]

The problem was completely sorted by buying a new prop same as original, it's a yamaha 200 2 stroke, highest recorded speed was 46 knots which is more than enough for me. I'm not going to mess with props again.

[Jizm]

Originally Posted by boristhebold

The problem was completely sorted by buying a new prop same as original, it's a yamaha 200 2 stroke, highest recorded speed was 46 knots which is more than enough for me. I'm not going to mess with props again.

Just wondered as I got 39kn on my 6.65m 200hp yesterday with a Merc offshore series 4 blade prop 22P? I think (Andy B will know, he looked, I'm not going out as it's pi**ing down!)
2 adults and 2 kids, lots of fuel and 5000rpm WOT.
About right?

[Andy B]

Originally Posted by Jizm

Just wondered as I got 39kn on my 6.65m 200hp yesterday with a Merc offshore series 4 blade prop 22P? I think (Andy B will know, he looked, I'm not going out as it's pi**ing down!)
2 adults and 2 kids, lots of fuel and 5000rpm WOT.
About right?

39kn's on year old fuel with the boats first run in 12months,
far from ideal conditions for a speed run and on a 4 blade prop!
not to bad me thinks!

[Jizm]

Originally Posted by Andy B

39kn's on year old fuel with the boats first run in 12months,
far from ideal conditions for a speed run and on a 4 blade prop!
not to bad me thinks!

agreed, is it a 22" pitch?