Yamaha 6m6 61x 62t and 64x question

[EightySeven550]

I have the following 4 engines
6M6, 61X, 62T and a 64X.

I also have 2 superjets these will go into.

What is the best combos I can make with these engines?

Thanks all

P.S. Whatever I dont use for the builds, will soon be in the "for sale" section.

 

[Boris]

What cylinder is on the 62T engine ?

 

[EightySeven550]

Dont know, I thought they were all 701s. How can I tell? this is from a 94 Raider.

 

[Matt_E]

That would be a 62T cylinder 701.
I would put the 64X engine in one SJ.

For the other, put the entire topend from the 61X engine on the T engine, and run that.

 

[#ZERO]

The 62T cases with a 61x cylinder would work great in a superjet and the 64x engine would work pretty well also.

You could make an extra backup engine from the 61x cases with the 62T 701 cylinder.

Just sell the 6m6 for parts.

 

[EightySeven550]

OK So heres the plan so far

64x into SJ1

62t 61x into SJ2

Should I use my 61x pistons along with my 61x cylinder?

 

[#ZERO]

OK So heres the plan so far

64x into SJ1

62t 61x into SJ2

Should I use my 61x pistons along with my 61x cylinder?

Yes.... use the same pistons in each cylinder if the compression is good.

 

[EightySeven550]

Just curious,

Why can I not just use the 62t cylinders? or whats the advantage of teh 61x cylinders?

 

[Mouthfulloflake]

depending on what sleeve is in your 62t cylinders, there is no difference between them and the 61x

 

[Mouthfulloflake]

err, sorry, I was mistaken.

62t cylinders suck, and are barely rideable in a stand up boat.

 

[keefer]

Port timing is different between the 61x & 62t cyls. The 61x cyl will give you better bottom & midrange, better for freestyle riding.

 

[Mouthfulloflake]

the height exh port height difference in the cylinders ive seen ( several of each) is really small. ( and porting generally makes them equal anyways)

but yeah, 62T cylinders SUCK.

 

[Matt_E]

They're terrible.

 

[keefer]

You could always put the 62t cyl on the 61x cases thus producing an aberration of nature that we call the Frankenstein engine. Some here say it makes good power. I built one with a milled stock head and a pipe and it had a good hit at 165psi. It would have been much better if the compression was increased to 180+.

 

[Mouthfulloflake]

the more compression the more they suck.

nothing sucks more than the 760 cylinders though, they have been known to throw people off the boat....

 

[#ZERO]

Actually the more compression they have, the more fuel efficient they are.

The higher blowdown time of the 760 causes more unburned fuel to exit out the pipe.

 

[Mouthfulloflake]

yeah, but 62T cylinders still suck.

you can say that again #0.....

 

[Freakrider]

the more compression the more they suck.

nothing sucks more than the 760 cylinders though, they have been known to throw people off the boat....

please explain....they have been known to throw people off the boat ? it is late now... and I am dumbfounded by that ? thx :crazy:

 

[keefer]

He just needs some better skillz so he won't get thrown off so much.:hitwithrock:

 

[Mouthfulloflake]

if you read and search, and ask around, you will probably hear that the 760 power band is all "top end"

and of course you know, thats terrible for a stand up, and will probably result in you being thrown from the watercraft in a spectacular fashion.

please explain....they have been known to throw people off the boat ? it is late now... and I am dumbfounded by that ? thx :crazy: