Converting Mercury 4 stroke 30hp to 40hp

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TIZUCK

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New member here. I was looking and I heard you can change a 1999 30hp 4stroke to a 40hp by only changing the resticter plate. Is this true or do you have to change other stuff?

Thanks in advance,

Tizuck
 
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TIZUCK

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Re: Converting Mercury 4 stroke 30hp to 40hp

Yeah, that was the post I was talking about but I wanted to make sure that is all I have to do so I don't mess anything up. He dose not state he ever did it. I don't want to know what someone thinks might work but as what will work.

Thanks,
 
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carholme

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Re: Converting Mercury 4 stroke 30hp to 40hp

Why not just send Faztbullet a PM and ask him as he is the one who advised you that it is only the isolater which needs changing.

Gerry
 
Silvertip

Silvertip

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Re: Converting Mercury 4 stroke 30hp to 40hp

You can also go through the entire engine parts list for both engines while comparing part numbers. Any part number that differs between the two engines means that part is different. Decals for example would have different part numbers. If a restrictor plate is used, the 30HP parts list would show it while the 40HP would not. If the cylinder head or ECU part numbers are different then you know those parts are different (and expensive I might add).
 
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TIZUCK

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Re: Converting Mercury 4 stroke 30hp to 40hp

I did that and he never got back to me. I might just try it, if something bad happens it will give me a good excuse to the wife to buy a new 75hp.
 
Faztbullet

Faztbullet

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Re: Converting Mercury 4 stroke 30hp to 40hp

TIZUCK you have a pm, I took some family time off this weekend. The difference in the 2 cylinder 2 stroke is just a carb and the 4 stroke is the isolator. The only difference in the powerheads is the crankshaft to allow the bigfoot lower unit as driveshaft is larger.
 
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causing

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Re: Converting Mercury 4 stroke 30hp to 40hp

Faztbullet said:
TIZUCK you have a pm, I took some family time off this weekend. The difference in the 2 cylinder 2 stroke is just a carb and the 4 stroke is the isolator. The only difference in the powerheads is the crankshaft to allow the bigfoot lower unit as driveshaft is larger.
Click to expand...

Hey Faztbullet. I was wondering if it is the same procudure for yamaha F30 (only replacing the isolater). It was also build from 1999 and carbed (mine is from 2001). Is there any need of any adjustment to the carbs after replacing that isolater? I heard that the mercs have a yamaha base, so its probably not a problem...? But i'am not sure.

Gr, Stefan, Amsterdam (could not find any native forums about it)
 
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scotty m

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Faztbullet said:
Re: Converting Mercury 4 stroke 30hp to 40hp

TIZUCK you have a pm, I took some family time off this weekend. The difference in the 2 cylinder 2 stroke is just a carb and the 4 stroke is the isolator. The only difference in the powerheads is the crankshaft to allow the bigfoot lower unit as driveshaft is larger.
Click to expand...
Hi Faztbullet
I am interested in 30hp to 40hp upgrade on my Mercury four stroke EFI. You mentioned the "isolator" where is that located on the engine?

Regards
Scotty
 
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