Small outboard carby

[PADDLES]

Is anyone familiar with carby's on small outboards? I've got a 1981 Suzuki DT8 which has got a carbureter issue. I don't have a manual but do have a parts diagram.

Anyway, it's a little Mikuni carby and it has a little brass tube inserted into the hole in the centre of the drain plug. This little tube then goes up the centre of the carby into the tube that the main jet screws into. This tube doesn't show up in the parts diagram for the carby, does anyone know what it does?

If I can't get the thing running properly I think it can just go on ebay for parts/wrecking.

[Tracker]

http://store.brownspoint.com/pdf/DT8%2883-85%29.pdf
page 7 fig 4.is what you need there?

[Roughasguts]

It might be there to keep the fuel levels up to the main jet (keep engine running) while the engine is tilted! and on full lock, for near beach, shallow water Etc.

Cheers.

[PADDLES]

thanx tracker, i've been looking on the brownspoint diagrams and the little tube still isn't shown. good point roughy, that might be why it's there. i've now downloaded a service manual for 6 bucks so i'll do a bit of reading.

[finga]

Let us know how you get on with it eh

[PADDLES]

no worries finga, i'll keep you posted. i've played with bikes a bit but never with outboards.

this motor came with a tinny i bought and i wanted to get it running so the father in law can use it on his little 10 foot car topper, it's got spark and i can get it started sometimes, but it dies. i can tell it's getting way too much fuel so i'll start by looking at the needle and seat and the float height. i've now read that if the seat gets damaged in these early mikuni carbys that they're a throwaway, so i hope that's not the case.

[PADDLES]

hey finga, i got it starting and running reliably. i cleaned all the gum off the needle valve so it moved freely and used a drill bit and lightly spun it with my fingers to ream and clean up the seat and it seems to have worked well. it starts about third pull when cold and first or second pull when warm and buzzes along beautifully.

it wasn't pumping water so i pulled the gearbox off and then opened it all up, there was a bit of water in the leg oil so i cleaned it all up with a bit of petrol and then some white spirit to get rid of any trace of water. so it looks like it will need a water pump kit and new shaft seals, i also figure whilst seals are being removed the bearings might as well be replaced too.

the long and the short of it though is that i've decided to sell it as is, i've done the bulk of the trouble shooting. it was actually going to be for my father in law who's 70, and the last thing we wanted was for the old bugger to be stuck up the creek and having to row home. so even though it seems like it could be made into a good thing, it's still 30 years old and we (wifey and myself) didn't want to take the risk. even if someone didn't want to get the lower unit issues sorted and use it, there are some quality parts on it for someone who's already got one of these motors and wants to keep one going.

[Noelm]

That tube you refer to is called an "emulsion tube" pretty common in small carbies, lots of old 4 stroke mowers had the same thing, not 100% sure what it does, but I guess from the name, it must do something (emulsify?)to the fuel before going through the main jet.

[Roughasguts]

That tube you refer to is called an "emulsion tube" pretty common in small carbies, lots of old 4 stroke mowers had the same thing, not 100% sure what it does, but I guess from the name, it must do something (emulsify?)to the fuel before going through the main jet.

Hmmm emulsify could that apply to water contamination and some how mix water and petrol together ???.

Cause if it is ! wan't a big one to put in me car and go half water and petrol to save some money.

Cheers

[finga]

Oi Rag...mate. There used to be an old guy at Alstonville who had an old 6 cylinder LJ or LC Torana which had water injection in it.
Apparently it saved him megabucks on fuel and it did no harm to the engine and in fact the guts of the motor were extremely clean according to my younger brother who did the servicing on it.

[Noelm]

nah, I doubt it means anything like that, but a place I used to work was big in mowers, and I used to see the parts all the time, and it was always called and emulsion tube!

[Roughasguts]

Oi Rag...mate. There used to be an old guy at Alstonville who had an old 6 cylinder LJ or LC Torana which had water injection in it.
Apparently it saved him megabucks on fuel and it did no harm to the engine and in fact the guts of the motor were extremely clean according to my younger brother who did the servicing on it.

He he yeah thanks finga I have already done that back in 1979 with me crappy brand new Sigma, geeez I hated that car! anyway it actually went okay with water and certainly did clear out the exhaust pipe couldn't see out the rear view mirror for about 20 k's for all the black smoke and steam coming out.

Could only do it for a carby motor it might rust up the EFI and cost a fortune to fix with the later vehicles.

Cheers.

[Roughasguts]

nah, I doubt it means anything like that, but a place I used to work was big in mowers, and I used to see the parts all the time, and it was always called and emulsion tube!

Bummmer...

[Roughasguts]

He he well okay this here emulsion tube prevents an over rich mixture when idling and prevent spark plug fouling because of it.

Quads - especially those use in farming and ranching applications, have a large "appetite" for needle jets (emulsion tubes), too.
They are commonly left idling or just about idle while being used in spraying and other utility operations. Most "savvy" mechanics know that replacing the "emulsion tubes" will fix plug fouling problems resulting from overrich low rpm conditions.

[PADDLES]

thanx noel and rag, good info, i learn new stuff every day.