Hey ,

just recently i found a bunch of clips of people who have 4 motorbike carbs on there 4 k motors and other various motors, is this practical and does it work well?

 

also how do i know what size carbs will fit on my 4k motor?

Currently doing this to my 3tg, I'm using Keihin FCR41's which are 41mm. I had plans to put a set on my 4k before it blew up, and they were 32mm i think. If your going a fairly worked 4k i'd go for maybe 38mm carbies but that would consist of, big-ish cam, high compression and flowing exhaust. If you're keeping it relatively standard don't go anymore that 35mm in size.

 

Also you would have to make up your own manifold or adapt them to a twin side draught manifold some how. Wouldnt say its the easiest option, but its something different and it works wonders if its done right.

 

Carbies with all the black hoses were the ones I was going to use on my 4k, ones with red ram tubes are going on my 3tg.

Edited December 13, 200916 yr by toyota_ae71

wow awsome dude, so no bigger than 35, what will this upgrade n will it handle any different?

They should give you more power right through the rev range, as a big single carb is just a compromise everywhere.

 

Its just like fitting twin Weber side draughts, but more trouble!

 

It crossed my mind for the KE70, but I haven't got the gear to weld my own manifold up out of steel pipe anymore. SUs will have to do for me.

 

If you're keen you can airbox them with a cold air intake and run a recent-model Corolla filter.

Yeh Tommy (can't remember his full name) has a setup on his orange KE11. It's pretty mad, but you'd want to be reasonably slick with the fabrication for your manifold.

gaahhh whats cheaper.. cuz i can weld up sum stuff n fabricate a manifold?

gaahhh whats cheaper.. cuz i can weld up sum stuff n fabricate a manifold?

 

yeh man, grab sum pvc pipe n shit. hold it all together wif knead it. the chicks will go crazy for the cheapness :y:

 

In all seriousness, Have a look at TommyKE11's thread. He had a plate laser cut then just had runners directly to the carbs. manifold fabrication and laser cutting wouldnt cost too much. The carbs would be the most costly part of it IMO

The carbs would be the most costly part of it IMO

 

Agreed! :y:

Agreed! :y:

 

But thats just me, I have access to most things to fabricate a manifold etc.

 

Someone might get a workshop to make them a super titanium, gold plated manifold. then the price of the carbs would probably be the cheap part :P

Someone might get a workshop to make them a super titanium, gold plated manifold. then the price of the carbs would probably be the cheap part :y:

 

hahaha yeah i guess your probably right there. If i can find the right size alloy, that's what ill be making mine out of. The first set i brought for the 4k were under $100 but the keihin's were $500. Hope to god its worth it. Although Jay from B-parts had them on his 4ag and produced 115rwkw.

hahaha yeah i guess your probably right there. If i can find the right size alloy, that's what ill be making mine out of. The first set i brought for the 4k were under $100 but the keihin's were $500. Hope to god its worth it. Although Jay from B-parts had them on his 4ag and produced 115rwkw.

 

Wanna sell the 32mm's?

Sold them to another member on 86dc 12 months ago. look on ebay mate, theres usually a fair few around. ill have a geez for ya :y:

Sold them to another member on 86dc 12 months ago. look on ebay mate, theres usually a fair few around. ill have a geez for ya :y:

 

Thanks mate :P

 

What are they off of, if you know?

 

CHEERS

Ryan

FCR keihins are pretty common on later model 4 cyl sports bikes. Also see mikuni's come up as well. Just Ebay search Mikuni/Keihin.

just remember to allow funds for a reground camshaft and new valve springs, or it will be a waste of time,