yamaha 70 ces

[Roy Hodges]

Can you tell me what's the dif in weight ,between the running POWERHEADS , of a
75 hp 49 in OMC ;and a 90 HP yamaha ? It seems to me that a sport E boat or a mod 50 boat , with a stock 90 yammy powerhead on a sport E tower &lower unit ,with nose cone & low water pickup would be the cats pajamas !

[Fast Fred]

from shippin them out i know a Stinger, in full dress is right about 100#, the 90 was feelin like about 140# when i pulled her off, what's up Yard Bird

[mobil1]

there is two styles of 90hp carbs, the square style fit right on, the round style you need to change the screws in the top of number 2 and 3, number 3 needs some room between the tray and the bowl, if you don't want cut the tray, you can sand off the bowl and just get it.
i liked the round style best.

I have the round style, as i remember.
What do you do with the electric choke, does it fit the 90 carbs?
And the rods connecting the throttle levers of the carbs, do they fit?
The boat and engine stands in winter storage, so i can't check anything...
Trying to work everything out before the season starts so i can mount them fast...

regards

[Fast Fred]

on the 90hp power head, you want the carb studs in the intake. choke, remove choke plates, toss them out. 70hp gang linkage works on the 90carbs. thinkin you my have to cut the tray.
you want to open the intake so it is the same as the 90hp gasket, i cut 1/3 off the reed stops. you will need a new throttle cam. no air silencer,

[Fast Fred]

[Fast Fred]

and one more

[mobil1]

thats clear...
Now waiting for better/hotter weather. First test with the 70carbs and cleaver.
The i will try the 90hp carbs.

Thanks for the info, looks neat on the pics.

[Fast Fred]

a good place for a half set of 250hp carbs, be on the front of the 90hp

[sharpeye Mike]

Hey! We should start a thread on the mighty 90 Yammy......Well not me but maybe one of you connoisseurs, it seems to me that theirs lots to say about this motor.

[mobil1]

Still bad weather over here but drove the cat 2 times last month.
First time was good, acceleration ok. Top speed fast!
After that run checked the plugs and the where on the lean side, to lean for pleasure so i richend them up one size.
Following time on the water acceleration was bad, difficult to pick up rpm's after a turn.
The cleaver i bought is a size to big, think i need a 11 x 20.
With the 11 x 22 i was turning arround 6400 rpm.