yamaha's

lucasv · 26-05-2012, 12:52 AM

does anyone knows the difference between the 1996 200hp v pro's and the 225/250hp yamaha's from the same year? is there any way of upping those from 200 to 225 or 250?

OCRDA · 26-05-2012, 06:59 AM

Carb or injection ? The 200 Pro is almost certainly same as 225 2.7 litre. the 250 is bigger at 3.1 litre

scooby_hugh · 26-05-2012, 10:39 AM

The 150, 175, 200 and 225's are the 2.6 litre and can have carbs swapped and ign timing set to make them whichever one you like

Toffy · 07-06-2012, 11:58 AM

I have the carbed 200hp 2.6liter. So I could turn it relatively easy into a 225hp ? Aren't certain parts designed for 200hp ? Don't want to risk damaging what works flawlessly now.

greets, T

still no worries · 07-06-2012, 01:35 PM

My mates 200 v-max had 1mm off the heads and you can notice the difference.

Toffy · 07-06-2012, 05:14 PM

Sorry mate, but I'm no specialist. Could you give a bit more info ? You mean 1mm less piston height compared to what ? did you make this mod yourself or is a V-max default like that ? Difference in comparison to a normal 200 or a 225 ?

Still very interested in this thread !

gmc · 07-06-2012, 07:21 PM

Quote:

Originally Posted by still no worries

My mates 200 v-max had 1mm off the heads and you can notice the difference.

I bet you can notice the difference!!

Yamaha 200 2.6 blown up spares 20" leg
Offers, (please don't ask how much as its a mates and I don't know !)

still no worries · 07-06-2012, 08:09 PM

Quote:

Originally Posted by gmc

I bet you can notice the difference!!

Yamaha 200 2.6 blown up spares 20" leg
Offers, (please don't ask how much as its a mates and I don't know !)

Same mate different motor, he's got three of them, John you've seen the v-max go on robs boat (80 mph on gps)

still no worries · 07-06-2012, 08:13 PM

Quote:

Originally Posted by Toffy

Sorry mate, but I'm no specialist. Could you give a bit more info ? You mean 1mm less piston height compared to what ? did you make this mod yourself or is a V-max default like that ? Difference in comparison to a normal 200 or a 225 ?

Still very interested in this thread !

Hi
You just remove the cylinder heads and have them skimmed (1mm)then replace with new head gaskets and torque them down.

Toffy · 08-06-2012, 12:07 PM

Still learning here...

So you're skimming both of the heads with 1mm and leave the block and pistons untouched, right ? So, the remaining cilindervolume at TDC becomes reduced, therefore compressionrate is higher and this results in a more powerfull powerstroke ?

Is this what you have to do to turn a 200 into a 225... or does this modification lead to higher powerrates, and therefore decreasing lifespan of your engine or risk to blow the block ? What hp does your motor produce now with this mod ?

Still very interested, but that's clear by now

Cookee · 08-06-2012, 12:32 PM

Quote:

Originally Posted by Toffy

Still learning here...

So you're skimming both of the heads with 1mm and leave the block and pistons untouched, right ? So, the remaining cilindervolume at TDC becomes reduced, therefore compressionrate is higher and this results in a more powerfull powerstroke ?

Is this what you have to do to turn a 200 into a 225... or does this modification lead to higher powerrates, and therefore decreasing lifespan of your engine or risk to blow the block ? What hp does your motor produce now with this mod ?

Still very interested, but that's clear by now

It's a rule of thumb that modifying an engine does not increase the life or reliability of an engine!

Toffy · 08-06-2012, 01:28 PM

Quote:

Originally Posted by Cookee

It's a rule of thumb that modifying an engine does not increase the life or reliability of an engine!

I agree! But you can keep an engine 'on the safe side' still reliable , or you can mod it very high performance with risk of blowup.... I hope I'm explaining this correctly in English.

What I'd like to know is on what side the described engine mod is and what sort of resulting hp we are talking here: is this risky business or is your engine still reliable ?

Big Dutch · 08-06-2012, 04:13 PM

I don't think farting around with the engine will make you go any better then getting a really great prop worked and balanced and thinned -just a thought.

still no worries · 08-06-2012, 04:31 PM

hi
the best thing you could do would be go and see nico at bernico boats he will be able to tell you all you need to know, it cant be far from you so take the boat with you....

Toffy · 08-06-2012, 04:42 PM

Thanks guys, I know Nico but he's more a Merc guy and I'm just looking for forum-info here

Sorry to hijack your thread Lucasv

bigboy · 08-06-2012, 04:55 PM

Quote:

Originally Posted by Toffy

I agree! But you can keep an engine 'on the safe side' still reliable , or you can mod it very high performance with risk of blowup.... I hope I'm explaining this correctly in English.

What I'd like to know is on what side the described engine mod is and what sort of resulting hp we are talking here: is this risky business or is your engine still reliable ?

Shaving the heads. So basicaly you make the heads smaller which bumps up the compression and performance.

If you do this than I believe you always have to run on 98gas which may not be for sale everywhere or harder to get (f.e. if you go on holiday and take the boat with you).

Toffy · 08-06-2012, 05:19 PM

So I was right then, thanks bb! ... and my google search redirected me to... boatmad !!

all shaving/skimming heads info -> http://www.boatmad.com/forum/showthread.php?t=5693

deepvee · 08-06-2012, 05:34 PM

Quote:

Originally Posted by Toffy

Thanks guys, I know Nico but he's more a Merc guy and I'm just looking for forum-info here

Sorry to hijack your thread Lucasv

once youve gone black you never go back, ha ha

Cookee · 09-06-2012, 08:11 AM

Quote:

Originally Posted by bigboy

Shaving the heads. So basicaly you make the heads smaller which bumps up the compression and performance.

If you do this than I believe you always have to run on 98gas which may not be for sale everywhere or harder to get (f.e. if you go on holiday and take the boat with you).

I'm afraid you believe wrong! It depends on how much you skim the heads by and what compression ratio you end up with. The guy with the 1mm heads in Salcombe runs regular pump fuel as far as I know.

bigboy · 09-06-2012, 09:38 AM

Quote:

Originally Posted by Cookee

I'm afraid you believe wrong! It depends on how much you skim the heads by and what compression ratio you end up with. The guy with the 1mm heads in Salcombe runs regular pump fuel as far as I know.

Cookee I said that he will need 98 which is regular fuel. But if he's going on holiday to fe Kroatia it may be harder to get 98 while it's no problem to get 95! Something to consider...