Hi,

I was wondering if anyone has any bright ideas about why i have 'hesitation' or an unwillingness to go faster at slow acceleration (part throttle, low load). If I nail it it spins up to 6000rpm (my self imposed limit) very happily, no worries at all.

Basically, it accelerates well under heavy load, full throttle conditions, not quite so happy just creeping up.

What are the basic things to consider about this, where would the problem be?

1310cc
Twin HS2 SUs, reconditioned, matched, in VGC as far as I can tell
Maniflow inlet manifold and LCB
"AH2" needles ('rich' cooper s needles)
20w monograde oil in dashpots, correct level
ITG air filter on KC's ultimate filtration kit (stub stacks)
Fuel regulator regulating pressure to a steady 2.5PSI

Cheers
Matt

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68 Deluxe.... it's shiny..... I like shiny!!

overfueling

or

plug gap

or

coil

Not enough throttle?

What springs do you have in your SUs? Possibly a little too stiff?

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1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T

Thanks BIAM,

Overfuelling i will investigate, would it be the kind of thing caused by incorrect needle profile, or would it have to be 'bigger' such as needle valve, flooding essentially?

The coil is a new GT40T, may be at fault, might have to sub in another, see if it changes anyhting.

Plug gap is 35 thou I think, I also use a 123 ignition dizzy, so plenty of spark available.

Keep the ideas coming people!!

Matt

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68 Deluxe.... it's shiny..... I like shiny!!

Using the Cooper s springs, red I think. Slightly stiffer than the cooper Springs. Tried the blue ones, just didn't feel right, let the motor hunt a bit at constant revs. (very marginal hunting, I am picky).

There are times when i like to drive without using full throttle......

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68 Deluxe.... it's shiny..... I like shiny!!

I know you said refurbished SU's, did that include the throttle shaft bushes?

Air sneaking in there could be the cause.

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'72 clubbie, 1360,twin hs2,loud.- and currently broken
'06 Ducati Monster S2R 800

Hmm, doesn't sound like springs then, Cooper S would be the correct ones.

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1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T

don't forget change a spring change the Needle
also a reminder Check you fuel filter also

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Stop Licking the Dog...I Don't Care Who Started It

Hi

Yep, brand new shafts, which removed 100% of the 'slop' in the shafts. Good idea tho! I've also checked manifold to head mounting etc, no leaks.

Matt

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68 Deluxe.... it's shiny..... I like shiny!!

Hi Gaf, the current springs are the cooper s type, and the needles are the AH2 cooper s 'rich'. 'should' be suitable.

I guess a dyno run would help, the motor is so far from standard that trying to use 'standard' needles etc is only ever going to be a starting point!

Thanks!

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68 Deluxe.... it's shiny..... I like shiny!!

Try closing the plug gaps a bit, I find .032" better than .035" with the electronic Pulsar dizzy. At .035" it does that too when cold. It takes more energy to spark a lean mixture..

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.