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MG MGB Technical - carbs ' crosseyed'

I have been out of scene because i am busy the honda s800.
Its hard to get tecnical info or expertise on this car, but the question is regarding the carbs,
its basically a copy of Su's, the needels are tappered but the jets are straight bore ,fixed and not adjustable.
So i can not adjust the petrol misture, just air intake by means of individual jet screws.
the engine works well without air filters, but once fitted its caughs, by pulling the choke it comes right, so i thing it runs lean...
any bright ideias?? new spark plugs, points, leads etc..
Thanks

here is the little bugger
http://groups.msn.com/Carrosemotasclassicas-/hondas800.msnw?albumlist=2

Alfredo

alfredo

There should be mixture adjustment screws on the side of the carb, similar to an HIF4. I've never known a carb to not incorporate a mixture adjustment. That would be like a car without a throttle pedal.

Jeff Schlemmer

Try asking on here
http://www.honda-s800-club.freeserve.co.uk/

Looks a newish site but there should be someone there who can tell you what you want to know.

Colin

C J Bryan

Just found this link may be of use to ID the parts on your carbs
http://www.sudco.com/cr_diagram.html

Colin
C J Bryan

Colin - great website! It looks like those carbs need individual jet changes and needle changes to tune. Those carbs have as many variables as tuning a Weber DCOE!
The following is a better link to the full parts info.
http://www.sudco.com/catalog105/096-105.pdf
Jeff Schlemmer

Colin, i think these bike carbs, they similar but diferents,
thanks
Alf
alfredo

alfredo

yes guessed they were bike carbs and couldn't find any reference to the S800 on their site despite them manufacturing them.
Having had a further look around came up with a link to Honda engine diagrams try
http://www.honda.co.jp/memory/mem-s8/s8parts/s8list.html
Item E13 in the list brings back the carbs picture and parts listings.No detail of the internal parts of the carbs are shown but at least you can see if they are the ones you have.

I found it easier to find them in the listings by getting Google to do a Translation from the Japenese to English

I think Jeff may be right about them needing indivudual jet and needle changes to tune them, A Motorcyle mechanic could tell you for sure if you have one near to consult.

Just thankful I only have a pair of SU's to work on!!!!

Hope this info is of use to you.

Colin
C J Bryan

Alfredo - the S800 used Keihin carbs similar to those used on bikes. Honda designed and made them.

Love the S800 engine - but I'd rather have an S2000 in my MG..........
Bill Spohn

Colin, thats the one E13, but is not easy to translate.
i had a reply from Norman Hart in US,apparently is an expert on this cars, hope to get some answers.
thanks
Alfredo
alfredo

Alfredo,
When you last mentioned you had purchased a Honda S800 I had posted that I had a copy of a magazine (Classic and Sportscars) which did a comparison test a little over a year ago, between the Honda and an MG midget, Well I finally found it but as yet to scan it into my computer. If you email the above with your email I'll be glad to forward it to you.
John

here some more pictures..not in bad shape...

http://groups.msn.com/Carrosemotasclassicas-/hondas800.msnw?albumlist=2

Alfredo
alfredo

Alfredo,
Keihin carbs were used by Honda for their motorbikes as well so perhaps a bike shop may be able to help?

Cheers , Pete.
Peter Thomas

I would like to thank John Mancone for sending me as he promissed, the classic magazine where it shows comparison test between midget and honda s800.

Otherwise i managed to tune the carbs not 100% but acceptable until final restauration.
alfredo
alfredo

Your welcome Alfredo, enjoy the car.
John

Alfredo, The carbs are tuned by a clip at the top of the needle. Look at the carb parts diagram Colin posted. See the needle #12 and the Clip #13. Usually motorcycles will have the clip in the center retaining ring. Move the clip down to for a richer mixture and up to make the mixture leaner. Hope this helps.

Clifton
Clifton Gordon

This thread was discussed between 14/10/2005 and 25/10/2005

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.