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Last night I finished up the brakes on the Colt and went for a test drive. Just like a little roller skate! The old neighbor dude gave me lots of dirty looks, but I told him "I was going under the posted speed limit. It just sounds fast."

I've got a side draft intake manifold with duel Mikuni 44's, or at least I think that's what they're called.

Does anybody have a source for info. on these things? I'm looking to buy jets and stuff like that.

This weekend the motor will be inspected with a leakdown gauge, timing issues inspected, etc. If the leakdown and timing doesn't prove to be the problem I can only think it's the carb.


Brian "Where's my laptop and engine program?"}>
 

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Brian-

A Carburator (UK: Carburettor) is a device that provides for the mixing of fuel and air at atmospheric pressure, then uses the vacuum created by the lowering piston in the cylinder to draw that mixture into the combustion chamber. It is an amazingly primitive device but has the advantage of working even in the absence of a an electrical current, to say nothing of the absence of a laptop. It was very popular in the days before the Mercedes 300SLK and indeed remains popular in India and Mexico, although it is losing power (har har) there as well.

Your Mukini (by licencing agreement with Weber) carburators are of a shockingly primitive design that requires different "jets" for different mixtures at different load ranges of the engine, and switches between these "jets" by a mystical and unpredictable algorithm known as the Dark Science.

A truly futuristic design of the carburettor was, shockingly, developed in Britain by the "SU" company. As with all time-hono(u)red British "design" this was sketched on the back of a napkin after a jolly good load of Gins and Tonic (Gynnantonix). "What," reasoned the post-Gynnantonix British engineers, who were really just a load of Harrow-"educated" ne'er-do-wells who liked the smell of petroleum, "is the key behind the Dark Science?" Much pondering went on, and several more Gynnantonix were consumed (per engineer), until eventually the last one standing said "I've got it! The more it sucks, the more we'll give it!"

Much experimental sucking of the legs of chairs (which were then convenient to the maximally-entropied (on the floor) heads of the "engineers") went on, until someone managed to extract the chair leg from his mouth and said "by George I think we're on to something" and the variable-jet SU carburettor was born (or, rather, stillborn as in their hangovers they all forgot what they had said the previous night and it was not until weeks later when someone noticed the paint missing from the chair legs and inferred that they must have been at this for a while so was sharp enough to go easy on the Gynnantonix and note the insight as it happened (again) that night).

And then a bunch of Germans invented fuel injection and the fun was over.

ACP
Flirting with the laws of history.
 

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your other left, you idiot
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Kudos to ACP.

And from the learned Dick O'Kane: "Carburetor is a French word meaning 'leave it alone'".

Seriously, roundy-round guys still use carbs. And your buddy, Scott Jr. could ask his dad. Webers always were considered an arcane "science".

press on,
jimmy
 

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just another old phart
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ACP said:

>Brian-
>
>A truly futuristic design of the carburettor was,
>shockingly, developed in Britain by the "SU" company. As
>with all time-hono(u)red British "design" this was sketched
>on the back of a napkin after a jolly good load of Gins and
>Tonic (Gynnantonix). "What," reasoned the post-Gynnantonix
>British engineers, who were really just a load of
>Harrow-"educated" ne'er-do-wells who liked the smell of
>petroleum, "is the key behind the Dark Science?" Much
>pondering went on...

It is my understanding that the reason it is such a "Dark Science" is that the particular Gynnantonix emporium in question was lit by products of the Lucas Electric Company. ;)

Kent Gardam ((not being one to let the opportunity for a Lucas Electric (now there is an oxymoron) dig go wasting))
 

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400 flat to crest
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Oh you poooor thing, those saddled with Mikunis or more properly Mikuni/Solex aka Soil-ex (as in the quaint term for what goes in the chamber pot "night Soil" or Soil+ ex from latin for former or from to wit former Soil) must first and formost detirmine WHICH Soil-ex PHH or whatever they have. There are about 5 variations on the bodies, unlike the Weber which my have some little "off idle bleed" differences but are in essence the same stuff since the last century!!
I'll send a link later to a place which has silouettes of the different carb tops, that's the first thing.
As always with carbs, the first question is always cleanliness in all the passageways and to that end Gum-out and the red squirty tubie thing are you first tools: cram that in anything that looks like an orifice and blast away. and don't be stingy.
next establish a base line and use notes.
There are things called "Pencils" and some get all obsessive and insist that you use only some Kraut 0,2 (null komma zwei) mm mekaninische blei schrot-dinge, but any pencil will do.
Get some tape and stick it where it won't get lost and thern draw a little piccie of the carbs and then make a note of the turns out each screw is that control VOLUME and throttle schtopp!!
Get the terms right to understand better what you're doing.
Example, the thing that peeees out fuel at and just off idle and the source of most big stumbles and coughs is not the "mixture" screw, it's the volume control screw, it controls the Volume of mixed air/fuel that passes by. The mixture of that fuel was detirmined by the fixed air and (austauchbart) fuel jets.
Note if the things are say 1.75 turns from their seats or if some are way out and some seated.
Run them all volume screws in then come out say two turns.
back the throttle stops off then run them up til they touch and then give each a turn.
Disconnect thottle linkage and fire it up.
See first you gotta get it to be a carbioe question and not a linkage issue, so eliminate the linkage variable.
then report.

I have suggested to several friend who have Mikuni/Solexes to sell them on Ebay for millions!!! to the resto-pervs out there where the demand is high mongst Dastsun 510 pervs and get some Webers so that all the vast knowledge is available to get you going.

EDIT>here's a link to that palce with gasket silouettes so you can ID the carb you have before you call all the joints everybody else has suggesting.
http://shakekun.hp.infoseek.co.jp/page078.html
Rots o ruck round eye!

John Vanlandingham
Seattle, WA. 98168

Vive le Prole-le-ralliat

Black Rocket Rally Tires
http://www.blackrockettires.com/
 

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400 flat to crest
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5,777 Posts
>
>Brian-
>
>A Carburator (UK: Carburettor)
or more commonly Carbie


is a device that provides for
>the mixing of fuel and air at atmospheric pressure, then
>uses the vacuum created by the
exit of the high pressure charge out the exhaust leaving a low pressure area behind which the weight of 62 miles (or over France 100 kilometers) pushes thru the carb which, much like a drunken attempt at drinking whiskey with a bunch of Finns in London years ago, sorta slurps some fuel along. And the beautiful Indian girl from Bradford didn't need to sock me in the ear when I drooled at her well "bosom region".



lowering piston in the
>cylinder to draw that mixture into the combustion chamber.
>It is an amazingly primitive device but has the advantage of
>working even in the absence of a an electrical current, to
>say nothing of the absence of a laptop.
Sorta like "pens" and "paper"
It was very popular
>in the days before the Mercedes 300SLK and indeed remains
>popular in India and Mexico, although it is losing power
>(har har) there as well.
>
>Your Mukini (by licencing agreement with Weber)
Herr Edvard Weber is rolling 'im graben' junge!!
He may have been Austrian Jewish but his carbs were and are usually Italian, historically the Emprire of the Rising Sun have looked to "das Reich" for guidance.
such is the case in the Mikuni and Solex licencing arrangement....


carburators
>are of a shockingly primitive design that requires different
>"jets" for different mixtures at different load ranges of
>the engine, and switches between these "jets" by a mystical
>and unpredictable algorithm known as the Dark Science.
Or one does the unthinkable and looks in a "BOOK", a thing even older than "carbies".
If it were a Weber, then one could instantly get a "calculator", punch a few things and as I used to say in France "Viola manure!" you have a really good starting point.
>
>A truly futuristic design of the carburettor was,
>shockingly, developed in Britain by the "SU" company. As
>with all time-hono(u)red British "design" this was sketched
>on the back of a napkin after a jolly good load of Gins and
>Tonic (Gynnantonix). "What," reasoned the post-Gynnantonix
>British engineers, who were really just a load of
>Harrow-"educated" ne'er-do-wells who liked the smell of
>petroleum, "is the key behind the Dark Science?" Much
>pondering went on, and several more Gynnantonix were
>consumed (per engineer), until eventually the last one
>standing said "I've got it! The more it sucks, the more
>we'll give it!"
>
>Much experimental sucking of the legs of chairs (which were
>then convenient to the maximally-entropied (on the floor)
>heads of the "engineers") went on, until someone managed to
>extract the chair leg from his mouth and said "by George I
>think we're on to something" and the variable-jet
Variable venturi, or as some who have had to work on them in 37 degree sleet night call them by the "pommie" term "constant depression" carbies.


SU
>carburettor was born (or, rather, stillborn as in their
>hangovers they all forgot what they had said the previous
>night and it was not until weeks later when someone noticed
>the paint missing from the chair legs and inferred that they
>must have been at this for a while so was sharp enough to go
>easy on the Gynnantonix and note the insight as it happened
>(again) that night).
>
>And then a bunch of Germans invented fuel injection and
some clever "bosche chez Bosch" thought 'let's sell these old diesel pumps to the Luftwaffe for a million marks each,.....and they can shove them on the Diamler inverted V12s then they can sell them to our little "gelb freunden im Ost" and they can shove it on some Kawasaki but it was all too late so.....and they both lost the war to the 'Pommies', 'Ruskies', 'Froggies', and 'Yanks' who all opted to stick with 'carbies'
the
>fun was over.
for a generation or two...........
>
>ACP
>Flirting with the laws of history.






John Vanlandingham
Seattle, WA. 98168

Vive le Prole-le-ralliat

Black Rocket Rally Tires
http://www.blackrockettires.com/
 

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Sorry to interrupt with actual information......

TWM induction has mikuni parts.

In general, the fuel jet (at the bottom of the jet assembly) affects the mixture at low rpm and cruise, and the air jet (at the top of the assembly) has a greater effect at full throttle / high rpm. Smaller air jet = richer at high rpm, larger fuel jet = richer at low speed or cruise. Buy some time on a chassis dyno that can read hp and A/F ratio and go to town.
 

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Opel is a 4-letter word...
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RE: Sorry to interrupt with actual information......

I just ordered some venturis from Toysport in California for Mikuni 44's. They have a reasonable selection of jets, gaskets, and other parts in stock for the Mikuni sidedrafts. Mikuni no longer imports these carbs into the US, so the sources for parts are scarce.

Bob
 

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Here it is!!

Brian,

Ha! Deez kinderlings isht playying vis yoo! Naughty funny boys!

I have hardcopy of the Mikuni PHH books you need. E-mail your street address to me again and I'll send Xerox copies by U.S.Mail. (If anybody else needs them too, just send me an e-mail.)

In the meantime, here's the link to Overseas-Auto in Vancouver, BC. They show cut-away views and give you an on-line parts list. Just follow their site map to the "Mikuni Pages". I understand they still sell some parts they've managed to rathole all these years:

http://www.overseas-auto.com/Home/index.html

Your PHH's have the reputation of being easier to adjust than Webers and relatively maintenance free (Ouch, JVL stop that!). More than one competitor has told me they just set'em once, and forget about'em for the rest of the season. ;)

Rebuild kits & parts show up fairly regularly on e-Bay.

Oh yeah, and the Mikuni Company is very much alive and well making carburetors for all manner of Motorcycles, ATV's, Snomobiles, etc.
VIVE LE CARBURETOR!!

Rich Smith
[email protected]

Vive le "Pro-le-Ralliat"
 

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400 flat to crest
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RE: Here it is!!

Comrade Smith,
Having worked on both Mikunis and Webers and Soil-ex and Bing more or less continuously since about 1966 I'll say that the strength of the Mikuni and for that matter Keihin and Nikki is the consistancy carb to carb when doing jetting changes.
All of them are quite easy to work with and as I sorta hinted at, there are often all sorts of other peripheral issues, shall we say "installer induced" problems like linkage, poor sync, chafing cables , crappy return spring arrangement, no stops, never ever cleaning the filter in the inlet under the big brass nut on DCOEs, never cleaning the schmutz und scheisse in the emulsion tube well, etc.
I build motors with a bit more comp and bit more cam than most others I see in the US and I dont see any trouble or odd carb related issues that need continuous fiddling.
All the esoterica and voodoo seems to me to be a way to retain mystique and power thru withholding information with smoke mirrors and 'argot', they really are rather simple if one just stick to something there is information published for, and parts available for.
Readily-
So for resto-pervs go anything including Mikuni-Solex.
Gonna use the things-why stick with them??

John Vanlandingham
Seattle, WA. 98168

Vive le Prole-le-ralliat

Black Rocket Rally Tires
http://www.blackrockettires.com/
 

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RE: Mikuni numbers

Some baseline numbers for 44PHH carbs on 1600cc, C-2 engine from Mitsubishi publication # WE420501, "Galant Sport Kit Manual"

Main jet: 155
Air jet: 190
34mm venturis
Pilot circuit screw: 1 3/4 turns out
Fuel pressure: 3.56 psi


Follow Mike Hurst's advice and hunt a chassis dyno.

George B.


There's a chassis dyno way down here, (S. Illinois). A guy in town named Willy Krup has it at his shop. Willy's the exclusive supplier of specially reworked Holley carbs for a couple of race teams owned by some former football coach. (One of the drivers is named Tony something; the other one is named Bobby.) ...supposed to be big names. Don't know; I don't get to town much. ;)
 

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RE: Mikuni numbers

After resolving a barely running fuel pump and a distributor that had a jammed mechanical advance, the old girl runs a little better now. We also checked the jets in the carbs and they were correct according to everyone's advice.

Andrew, your Purple Chariot awaits...



Scott Radabaugh
 

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Of course, I likes the old SUs....

ACP, what other carb requires a good porter for its dampers? (Various stouts won't hold up, I believe it's the lower sugar content, and despite the humulus lupulus virtues of various IPAs, they are just too transparent to keep an HS6 happy under full acceleration). Samual Smith's Taddy Porter seems to be the best, of course only a small amount is required in the dampers, and it's a bloody shame to waste the rest of a pint bottle on the ground.

Is there some reason to use any other carb?
 

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It's always a tradeoff, Phil: too little in the carbs allows them to flutter; too much on the ground causes the driver's heart to flutter, and too much in the driver causes his eyelids to flutter.

SU used to manufacture a "flutter meter" that would, through various catalogued (but never seen) BMC attachments, connect to the carbs, the heart, or the eyelids, but they were discontinued after Leyland mechanics started connecting the carb fitting to the eyelids with predictable results.

ACP
Flirting with the laws of physics.
 
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