Has anyone put a 1.75 su on a 998 before? I am currently porting an unleaded head i got to replace the stock head, and while I was at it, I got a 1.75 with a water heated manifold to chuck on as well. I know I will probably run into problems with the jetting. Apparently the carb has been setup for a standard 1275, so I guess my real question is will this combination (worked head + 1.75) go well together or am I biting off more than I can chew?

Dont get caught up in the V8 scene, where they believe that bigger is always going to be better. Massive carbs, massive ports/valves, massive cams....

Id be inclined to go with a 1.5in SU.

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http://www.youtube.com/user/Hanras

or a small weber

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busier than a 0ne legged man in a butt kicking competion

webber would be www.flatspotmaster.com.au

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http://www.youtube.com/user/Hanras

Disregard the doomsayers and the weberists.

Yes the 1.75 in both HS6 and HIF44 form is a common carby on small bore motors. Graham Russell will tell you of a few well developed motors on his dyno, with a 1.75 carby, sucking all the air and fuel it can get.

It does have to be properly set up with t e right needle but its a good and common carby swap.

I have a 1.75 SU with a water heated manifold on my LS.. The motor was a 998 but has been bored out to 1030cc and worked over a bit but I found the 1.5 SU was just a bit to small to suit the new motor.

yeah, I have a HIF44 to go on my 998, just waiting on the head - let me know how u go!

thanks

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OK then what needle should I go with and any other setup issues I should know about so that I can buy everything I need before I put it all on?

Hahaha....!!! How long is a piece of string?

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http://www.youtube.com/user/Hanras

The first question that would need answering is "What Type of carb"???

That is to ask,,, is it a HS series or a HIF series

Float bown on the side???

or float bowl underneath????

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

float bowl is on the side, how do i tell if it is a HF or HIF?

What is the carby off originally ?? please dont say an Austin 1800

Its a HS6 btw but that doesn't matter greatly.

Is the fuel bowl on an angle to the main carby body or is it straight and in line ????

Buy an "OA6" mixture needle & shove that in & see what happens...

That should get you started & point you in the right direction mixture wise,,, the OA6 needle is a dam good "All-rounder" & will make just about anything with a 1.75HS carb on it work ok for starters.

But if you don`t quite know what you`re doing then just take it to some one who does,,, please???

& read what i just said again please,,,, the 0A6 needle is a good "STARTING POINT"
Not the be all & end all of mixture needles for your particular engine & state of tune/modification/package. Just a good starting point & wil;l run it ok till you have it tuned properly by some one who knows what they`re doing.

Treat it like a cheats way around tuning & because it will run pretty good straight up (as long as everything else is fine & dandy) you can tell everyone that you tuned it yourself & they will all think you`re a mini SU carb tuning GURU

ok,,, maybe not a GURU

But don`t tell anyone else , ok??? it can be our little secret

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

yeah maybe I should get someone who knows what they are doing to have a good look at it after all I am just a noob. Oh well gotta start somewhere... Oh yeah the fuel bowl is on a slight angle too.

agreed with Matt OA6.