yamaha 75 2 stroke becoming a 90?

[118118]

hi,
iv got a 2005 yam 75 2 stroke on my searider, and its great. but.... anyone got any idea how its restricted to 75? anybody made it into a 90?

it seems a relatively simpleish engine.... still on carbs... and its the same block.... so it must be do-able.

is it just a simple spacer between the carbs and block thats got restrictive holes, or more serious stuff?

thanks.....

[Jizm]

I may be wrong but I think it's done with carbs.

Have a look at a microfiche parts cd (ebay) and see what's different. The carbs were the difference on my 50 to take it to 60.

[jyasaki]

2-stroke? I'd guess you're right on carbs with port sizes and timing running a close second.

jky

[fast fred]

carbs

[fast fred]

hears them 90 premix carbs, thay make a set of oil injecter ones, they are square in style.

[Pete7]

Are you sure its the same block and not a tuned 60/70 block which were smaller?

Pete

[118118]

http://www.outboards-direct.co.uk/aw...p?vid=57&rip=1

yes, its definately the same block.
if its different carbs il leave it alone,

thanks

[Pete7]

Yep worth a check though. However if the 75 is in good nick and running well would you want to mess about with it. Spring is just around the corner, seems a shame to risk lots of problems just as its warming up.

Pete

[118118]

nope, it runns very nicely, only asking unless it was something simple,
swaping carbs is someting i dont want to do.....

thanks for your replys...

[John Kennett]

No use for 118118, but what's involved in upgrading an 85 to a 90?

John