Extra Long Shaft YES/NO ???

Pash 1 · 26-08-2007, 10:06 AM

Hi guys does this engine have an extra long shaft??
it on the cat and Roofer (Chris) says the boat is not suited to this engine if thats the case? can anybody explain why it wouldn't be

cheers
Martin

MrRob · 26-08-2007, 10:27 AM

it is an 25" (extra long shaft) I know that Roofer had a very similar engine on the back of his cat which if I remember right he said it didnt handle very well with such a large engine on the back.
If you really want this boat then offer the guy some expenses and take it for a test and if u like it have a marine engineer/surveyer give it a once over.

Pash 1 · 26-08-2007, 11:16 AM

when you say didnt handle very well what sort of thing should i be looking for on a test? as you can tell i havent got a clue, Blufin has told me what to look for when I inspect the boat but handling????
Cheers

Pash 1 · 26-08-2007, 11:34 AM

the other thing is im being told the prop turns counter clockwise!!!!! is that something I sould be warry off??

MrRob · 26-08-2007, 11:42 AM

I dont know the handling of such boat but I guess this may have something to do with the engine being heavy compared to a 2.5ltr. There isnt really anything wrong with having a CT Rotating gearbox other than getting hold of LH props wont be as easy as getting hold of RH props. But getting hold of a 20" RH Gearbox shouldnt be hard.

Pash 1 · 26-08-2007, 11:47 AM

So I could get the leg changed then?

verytricky · 26-08-2007, 11:50 AM

Pay £250 and buy Geoff Purvis's time and expertise. He will give a proper assessment and proper feedback on the handling of the boat. PM me for his contact information.

roofer · 26-08-2007, 12:28 PM

Quote:

Originally Posted by MrRob

. But getting hold of a 20" RH Gearbox shouldnt be hard.

I think you will find its almost impossible to get a gearbox for a 300 promax, ask Verytricky.

verytricky · 26-08-2007, 12:33 PM

Easy enough to get. You just have to pay full price!!! I finally ordered two brand new ones, and they arrived in three days!

Shiny and new and fecking expensive! £10k for the two.

However, there are dodgy second hand ones around at about the 2k mark.

MrRob · 26-08-2007, 12:47 PM

Quote:

Originally Posted by Pash 1

So I could get the leg changed then?

I think a 25" leg just has an adaptor that legthens it to 25" so I think all u need to do it removed the adaptor that lengthens it and cut the shaft down. If you find it have to get a 20" RH box then just have your 25" shaft cut down and have your gears swapped over to RH ones.

sterling · 26-08-2007, 07:35 PM

If you are lucky ,your Mariner 300 could have a 2 piece driveshaft.
The piece shaft that comes out the gearbox is very short ,and is connected with a round sleeve with inner splines and the part that goes into the crankshaft is the length you need for your type engine .
So if you have luck you only need a upper driveshaft,a few shorter studs /bolts etc

Not many were made by Merc with these shafts ,but its worth a look.