carburetors adjustment on 115 V4

[rodbolt17]

I think the 6K7 fit the old 220 excel.
the venture diameter is almost twice the diameter of the 6E5 or 6G6.

[vintageus66]

this relates to what I found on the net : 6K701 seems to be used on 200 or 225 hp. It was mounted when i bought the motor 2 1/2 years ago.
After one year of use, i gave it to fix to a (supposed) naval mechanic : the slow motion was too high (1800 rpm) and the mas speed was too slow (4400 rpm). I skip the details but when i got my boat 10 months after (yes, yes, 10 months), the slow motion was good (800 rpm) but the max speed was worst (2200 rpm). That's why i decided to do it myself ... but i need to learn a lot of things.
At the moment, i've set the 4 air screw at 1/2 turn on the 6E515 but i need beetween 50 and 100 key starter before the motor turns.
This is the reason for my question at the beginning

[almetelo]

dismantle both carbs and check if a least they looks identical (however this means nothing)

Check jets # (sizes) on both carbs.

[99yam40]

Why not ask the guy what he did to the motor?

[vintageus66]

@almetelo : they have been dismantled, cleaned in a ultrasound machine and dryed with compressed air. Jets were the same. But the air screw adjustements were totally different of what is advised by yamaha.

@99yam40 : because he is far away now

[99yam40]

e mail and phones reach a long way

[rodbolt17]

and at the end of the day,phone,email.
the 6K7 carbs will fit the V4 but the venturies and the jetting are wildly different.

[vintageus66]

he is far away and i don't know where he is. I even don't know his name.

This week-end i've dismounted the carburetors. When i opende one, i've mesured the float height. The first was 17 mm and the other was 17.5 instead of 16 +/- 0,5 mm on constructor values.
Is it enough to explain its difficult start ?
If it isn't what is the result of a non good float heihgt adjusment ?