AQ225E engine, AQ280 outdrive

Hi all,

i've just put together the combination from the subject line and had it put in the water this weekend.

A few questions, though:
1) Am I fine with the AQ280 outdrive with the AQ225E engine? Asking because the out drive was previously working on the same boat with 6 cyclinder AQ 170 (less power)?

2) I am afraid the AQ280 comes in 1.89 ration variation (I am assuming that because it was, as said, previously running with AQ170 which were supposed to run on 1.89 ration. For 225E, according to Google, 1.61 is best.

a) Can I solve this with a propeller only?

b) What dimension would you recommend? (5.8m boat, 1.400 kg fully loaded).

(Current propeller is completely wrong, needing 5000 RPM for 21 kts - note I just tried it couple of time and did not run engine on this RPM for long time).

c) What should I look at when buyinh new propeller? Only Volvo or other propellers fit as well? (in terms of shaft fitting)

3) The engine starts immediately when cold, but not so good when operationally heated - what should be changed/looked at with this engines?


Thank you very much for your answers/suggestion in advanced.

You are absolutely correct with your final drive ratio numbers!

The V-8 engine must use the 1.61:1!
You will never successfully "prop" your way out of this!

When changing lower unit from the 1.89:1 to a 1.61:1, there is a critical shimming procedure that must be followed!
Damage may result if you do not follow this procedure!



.

Thanks for the quick reply.

Would I 'survive' with this setup (1.89 ratio) for couple of month (the season on this part of the world ends end of September for me) and then do all the modifications during the off-season.

I mean - what can happen besides not running optimally? I am not that much into speed, just crusing at ±25 kts will do (which a boat of this size/weight with this engine should easily handle. I guess the fuel consumption may no be optimal but I am looking at apx. 80-100 hours of operation by then).

What would be ideal prop size for my current setup (14 x 25)?

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Damjan Slapar said:

Would I 'survive' with this setup (1.89 ratio) for couple of month (the season on this part of the world ends end of September for me) and then do all the modifications during the off-season.
Most likely, yes!


I mean - what can happen besides not running optimally?
The 1.89:1 lower gear set will have a lessor tooth count at the "drive" gear than the 1.61:1.
These means slightly less gear tooth contact at any given time, which means that this gear set is not quite as strong.
Go easy.... and it should hold up.

I am not that much into speed, just crusing at ±25 kts will do (which a boat of this size/weight with this engine should easily handle. I guess the fuel consumption may no be optimal but I am looking at apx. 80-100 hours of operation by then).

What would be ideal prop size for my current setup (14 x 25)?
If you stay within the same RPM range, you may be able to use the same propeller.

You just won't be able to take full advantage of the greater torque of the V-8 engine until the "taller" 1.61:1 is installed and propped.

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