Engine Upgrade

[karlws]

Hi I am hoping someone can help me with some information.
I want to upgrade my engine to a four stroke. I currently have a 70HP Johnson on a 2000 Stacer BayMaster 475 which has the pod on the rear. I have had this since new and the boat is still in pristine condition. The Maximum rating for the boat is 75HP. On the manufacturers tag back then they only recommended Max HP. My question is to anyone who may know is I am considering a 75 Honda or 75 Yamaha both these engines are around 40Kg heavier than the current two stroke. I know that four stroke engines were around back then so I am guessing that as long as I keep to the HP range I would be OK but I am unsure. I contacted Marine Hull who I am insured with and asked about the weight hoping they may know but was steered to the manufacturer who was also unsure. So is there anyone out there that has a 75HP four stroke on a 2000 Stacer BayMaster 475?
Thanks for taking the time to read this ... Karl

[sandef]

Your engine wt that your transom is rate to will guide your engine choice control thrust lower leg let's put a bigger prop to increase performance with lower engine at eg Merc 60 ct

[frozenpod]

40kg extra will hurt. You might be able to move the fuel tank and or batteries further forward.

[sandef]

40kg extra will hurt. You might be able to move the fuel tank and or batteries further forward.

Depends on what the transom is rated at I think it's only 140kg = a 60hp a 75 same as a 90 168kg

[frozenpod]

The boat will be setup for the existing boat motor combination.

Assuming the current setup is correct it will require adjustment when fitting a noticeably heavier motor.

[karlws]

Hi all and thanks for the input. I decided to err on the side of caution and went for the Mercury 60 CT.

[sandef]

Hi all and thanks for the input. I decided to err on the side of caution and went for the Mercury 60 CT.

I have a 450 topender transom is rated to 140kg I run a 60 merc ct with a 15 in prop I get 30knts at 4300rmp and is very fuel efficient

[sandef]

Trevor Yates at Bendigo marine is excellent for boat set ups