Outboards only revving to 2900 rpm????????????

[JOHNBULL]

Hi all,

I need help i have a pair of Mariner 40Hp on a 19' half cab. My problem is they get and go from take off great to 48 kph and approx 2900 - 3000rpm and that is it, i still have plenty of play in the controls but no more revs or go. I have looked up on the net and they should rev to 5500 -6000rpm. Is it possible that the last person that had the boat could have governed them somehow. I dont think that it has anything to do with the props that they have on as they get up and go from take off with no problems. Any help would be greatly appreciated.

Cheers Bull

[akman1]

wrong props most likely my guess if it gets out of the hole so good

[Spaniard_King]

Bull,
a few things to check

Are both engines acheiving full throttle at the engines. (check this by putting engines in gear and see if the carbies have the butterfly plates wide open)

2900 seems a bit low for 48klm/hr.. maybe your tacos are out

see if you can find someone with the same engine and see what sort of speed/rpm they get.. also find out what prop they have so you can compare.
The mmore I think of it.. ya probly not going to get more than 48lm/hr out of 80hp on a 19fter.. ya tacos gotta be out

some starters there for ya

[tim2]

What about a faulty Tacho?
edit:wrote this the same time as spaniard king

[Steven78]

At that speed i would be looking at faulty Tacho

[bigjimg]

Hey don'i forget you've got two engines.you have to multiply by 2 thats 5800rpm.Sorry could'nt resist Jim. Pointing toward tacho fault.

[Brice]

Yeah it has to either be the tacko or the props are a really high pitch.....or a combination of the two. What is the pitch of the props?

[JOHNBULL]

Thanks for all your help so far fella's.

When i got the boat one motor needed a CDI pack (i think that what it called) as the taco and the kill switch didnt work. Each motor has it own taco and they both read about the same within 100rpm. When you are doing the 2900rpm the motors dont appear to be working too hard at all. I dont know what pitch the props are as i am about 1000kms away at work at the moment but i will find out and let you know.

Thank again for your help.