Dual 44mm Mikunis on a L20B question.

Engine, Transmission and related drivetrain.
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paul97
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Joined: 07 Jan 2009 18:52
Location: Hanson Ma.

Dual 44mm Mikunis on a L20B question.

Post by paul97 »

I was wondering if you were running dual 40mm Mikunis on a stock L20B driven on the street would you have to run an electric fuel pump or will the stock one work fine?
demo243
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Joined: 19 Dec 2012 18:55
Location: Topsfield MA

Re: Dual 44mm Mikunis on a L20B question.

Post by demo243 »

You should have no problem with either. Many people running dual sidedrafts - weber and mikunis- using the stock fuel pump.

I ran a mechanical - dont think it was stock, but was never able to dig up any info on it - on my old L20b with hot cam and Mikuni 44s.

My guess is electronic fuel pump might deliver a more consistent feed of fuel... but also is one more thing to break or go wrong...

You would need to run a low pressure electronic pump and probably ideal to run a regulator to - Mikunis are pretty particular about fuel pressure - ideally between 3.5-4.5 psi. I am running the a Carter low pressure pump with a Holley low pressure regulator on my current Mikuni set up - Ive got an inline gauge in there too, mostly for setting the pressure initially, but now just to keep an eye on it.
'71 4 Door - Street/AutoX/Track Day Romper - Carb'ed KA24DE
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Byron510
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Re: Dual 44mm Mikunis on a L20B question.

Post by Byron510 »

You can certainly run either. I ran twin side drafts for years on stock type mechanical pumps in daily drivers.
If going mechanical, try to utilize the later L20B pumps from 78-80. These are higher volume - but not higher pressure. These pumps also seems to work better when high under hood temps weer causing problems with fuel boiling - a problem I had on one of may DD comunter cars years ago.
Also, if you can find a quality fuel pressure regulator and take the line pressure down to 2.5 to 3 spi - your needle and seats onthe carbs would love you for it.

Otherwise, you're good to go.

Byron
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because the opposite never works.
paul97
Posts: 669
Joined: 07 Jan 2009 18:52
Location: Hanson Ma.

Re: Dual 44mm Mikunis on a L20B question.

Post by paul97 »

Thanks for the info everyone.
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