[MarieK]

Hi,

I am wondering if you guys could answer a few outboard questions. I have a Mariner 75 4 stroke and was reading that the only difference between it and the 90hp is different carb, is this the case? and if so how much would the upgraded carb cost?

Also is there a big performance gain to be had from fitting an aftermarket prop, I am basically looking for faster to plane and/or top end, acceleration isnt such a big issue.

Lastly, has anyone fitted the doel type fins to their outboard? Do they make much of a difference, pro's con's would be appreciated.

Thanks,

MarieK

 

[ChrisP]

the carbs are different and the exhaust tuning is different. Carbs work out at about £300 each.

Aftermarket prop is the same as the mercury size for size, you may get a knot or 2 different as you may fitting a stainless prop. As long as the engine is operating within it's optimal rpm range changing the prop will not make a noticable difference.

I would not advise you to fit a SS prop as if you clunk it you not only damage the prop but there is also a chance of damaging the gearbox. Ally prop repair = @£50, SS repair >£100, gearbox= £ don't ask

I don't like fins simply because I have had a lot of cav plates to repair that were sheared off between the 2 drilled mounting holes. If they gave better fuel economy, better top end speed and easier planing I think the engine manufactuers would build them in, or at least make them as an aftermarket add on and strengthen the cav plate to take the loads. I have never had an engine fitted with them so cannot comment on their claims from personal experience. I have read and heard a lot of positive comments for their use.

Can you not trim the engine in to get on the plane and then trim it out for max speed?

 

[MarieK]

Thanks for the advice, like you I have read the reports of performance increase etc I will however probably just leave things well alone!

One thing i forgot, when using your outboard in saltwater how often do you flush it? The manual suggests after every trip, do you adhere to this?


Thanks

MarieK

 

[ChrisP]

Yes, I allway start it and warm it up on the muffs before I go out, better to find out if there are problems before launch

 

[sanctuary]

Most defiantly after every trip. I used to spend all summer on a caravan site and they were not best pleased with me using the water tap. I fixed up a large water carrier, a piece of hosepipe and a set of muffs syphoned the water down the hosepipe and attached it to the muffs best done when the engine is still warm so when you run it with the muffs on it opens the thermostat and completely flushes out the system.

 

[pincher]

Yes, I allway start it and warm it up on the muffs before I go out, better to find out if there are problems before launch

SORRY FOR SOUNDING STUPID,BUT WHATS THE MUFFS????????????????

 

[ChrisP]

They look loke a set of headphones that clamp onto the engine leg behind the prop and supply cooling water so you can start the engine on land.