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201 hop up project


Cpt.Fred

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thank you very much, greg!

that was a good read, i instantly printed that

and i'll follow it when i get to start the engine.

i have to buy a new manometer anyway...

hehehe.... "funky home-made manifold" ... i like the sound of that!:)

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it's alive!:eek:

no exhaust no nothing...

we set everything up as a first test and had a first try just for the sport of it.

it came alive on the first try:D

now i take evrything off again and fix some stuff...

fuel leaking out of the throttle valve shaft... no clamps on the fuel hoses...

and so on.

i'm a happy man for today!:D

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i admit i was merry as a lark in that moment,

since we didn't expect it to do more than some coughing and backfiring:D

this engine is amazing, it didn't run for half a year now and it came to live instantly.

i was very afraid i would have bad starting trouble with the new setup,

hence i went through all the fuss with the chokes and hand throttle and everything,

but apparently it works pretty well.

i'm a little worried about the gas leaking from the throttle shafts, though.

i will build my own gaskets for the spacer on the carb foot, where it seems

nobody is able to supply you with a decent gasket set for that area.

once i'm sure all three step up jets are working correctly i will know more,

when i still see gas down there i might have to wind my own springs for the jets.

i will also lower the float level a bit.

other than that everything seems to fit very nice, i have to move the wire loom a little and build a bracket for the dual horns, they're not in there at the moment.

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Fred You have Larks in Germany???? Probably das Ohrenlerche, Ja???

If you have raw fuel weeping out the throttle pivots it usually indicated needle valves not closing or a too high float level. Set them a 1/32 lower than factory. Remember you have 3x the gas in the float bowls than one carb, and each carb will be drawing 3x less gas each than the single. Each cab is only feeding 2 cylinders and air flow throug each carb is 1/3 of the total that used to flow throughthe single carb.

check for gas smell in the oil before you try to start it again. If there it supports flat bowls overfilling and overflowing.

Also did you set the accelorator pump linkage to their shortest stroke setting??? I did that on my duals.

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yep, larks everywhere! :)

Ohrenlerche, Hornlerche, Feldlerche, Heidelerche,

Bartlerche, Haubenlerche, and , my favorite, the Kurzzehenlerche!:D

i set the carbs up bone stock, that means pumps are now set up to medium stroke. but you're right i guess, and i will change that next time i get there!

float level will be lowered as well.

thanks greg!

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Fred, congrats, looks great, only one other thing that I'd be very careful about is that if there is any leaks from those carbies directly above the spark plugs...............spark plugs do spark........and live in a recessed area thats sometimes collects water.......so fuel might also collect.........I'd be making sure I had my new best friend, my FIRE EXTINGQUISHER very close and personal always........not trying to jinx you but I didn't realize that the carbs were that far over........but it looks great & sounds good........best wishes........andyd

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andy, you're right, it's good to be careful... the fire extinguisher is always at hand next to the driver's seat. not only since yesterday but always.

i don't want to see my car burn down, believe me.:rolleyes:

the carbs have new, selfmade gaskets on the middle part now,

the acc pump levers are in the shortest stroke position and the float levels are set

lower. i'm now waiting for some parts and then i continue.

does anyone know why this middle part spacer thingy is in the carb anyway?

it looks like it could be left out... and it's a major weakness when it comes to air leak issues.

i hope i can get a nice low idle in the end... i really don't like it when the engine races along at 800 or more at idle.

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I dont know why its there but I know there were atleast 3 different versions of it. Have to be very careful when picking the correct ones out of the carb kit to make sure the inner circle is the same size. There is another gasket in there that lines up with all the screw holes but has a slightly bigger inner circle which prevents a good seal.

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that's true, ed, at least 3 of them.

i checked all of them very carefully because i had the same trouble

last year when rebuilding the original carb.

this time the kits were a little better, but after i saw the gas leaking

down there once again i thought to heck with it and built my own ones...

it's a very interesting detail about these carbs, it makes them more complicated

and most likely more expensive in production, so maybe there is a different

version of it where the part makes more sense than on the D6A1 and A2 units...

i'll try to assemble one without it just for the sport of it, see what comes out:rolleyes:

eidt: just found some pics from last year where you can see the culprit and our step up jet vaccum test...

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Edited by Cpt.Fred
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What gaskets are you using between the carb and the manifold??? Are they slotted to provide a vacuum signal to that port on the bottom of the carb??? They must be open or you will have an over rich mixture.

If the vacuum signal is missing, the valve will be out of the seat at all times.

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yes, i know, i'm using correct ones:

20110329173525886_xovwmykifk.jpg

my only fear is that the vaccuum might now be too weak to pull the needle down

hard enough, now that it's only 1/3 per carb. that might force me to fabricate weaker spings somehow...

same thing with the ignition vaccum advance.

but let's see. crossing my fingers:rolleyes:

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Yep thems the ones, doesn't take much vacuum to hold them down, but if your plugs read rich after running for a while, that might be a concern. How much vacuum did it take to hold them down in your test??? That is one of the reasons why a balace tube might be beneficial, the cabs would have a vacuum signal all the time. With the inividual runners, the carbs will get a vacuum signal only from the two cylinders they feed and then only on each intake stroke. Something you might need to take note of down the road.

For timing, I have set mine at 6 degrees BTC at idle, I think this might be making up for the weaker vacuum signal to the advance. I run the advance from oe carb, but it is on a shared plenum so its got air flow all the time. You might want to plumb in all the carbs into that line to the dist so you have vacuum signal all the time.

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It would be an interesting experiment to connect a vacuum gauge to each separate port to see exactly how much vacuum there is individually and then hook them all together and check again for any difference there may be. Rubber hoses would make it fast and easy just for test purposes. I expect the readings will all be the same, separately and together.

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the fittings for all vaccuum purpose should be here by thursday...

i ordered everything i need to connect all 3 carbs to the dizzy.

the independant runner setup should guarantee a more steady vaccuum

on a small engine like this, i thought.

well, we'll see.

all i know is many guys using the 94 holley carbs in multiple setups are having problem with this issue...

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94 and 97 were are notorious for needing modifications to the step up circuit when used in multi cab set ups. Usually removing and plugging them in the seconday carbs, or rejetting to very small jets. But most of these ae run with progressive linkage, where one carb is primary and the other/s are secondary and only operate when the primary is at or close to WOT. The carters are much better designed and engineered. Techically since they are analog devices that operate on variable air flow, they are pretty much self adjusting, especially the main jet cicuit. Fuel flow is directly proportunal to the airflow (at least to the extent that their machining and build are accurate) so less volume of air the less fuel will be metered, in theory maintaning the correct AF ratio. But since the step up valve which is basically wide open at shut off, may not close all the way and or may open when the two cylinders in Freds set up are off line, since they will get only a partial and intermittant vacuum signal based on the vacuum in their individual intake runner.

It will be interesting to see what Fred runs into as he progreses, with set up and tuning his setup.

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amen to that...:cool:

thanks for all the input and help so far along the way, may it be advice or parts supply!

love this board...:)

I keep you updated as soon as i have new stuff here to go on with,

for now it's work work work to earn the money for me spleeeendid new toys!

best,

fred

andy: it seems your boys just taught ours a lesson ... hehehe. soccer stuff:rolleyes:

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Fred.......what did the Oz soccer team win something?........lol........that can't be right....lol.........andyd

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So we did some more testing and measuring today and i hooked up a little

exhaust and 2 mufflers to make it a little more comfortable to be around the engine when running.

this is interesting:

i took off the tops and we ran the engine with open float bowls to check step up valve operation (fire extinguisher at hand, andy:p).

check out the valve in the 3rd carb:

i changed the 2nd and 3rd carb afterwards and it stayed the same...

wonder if i might have a valve problem on cylinder #5 or 6?

the step up valves on the first 2 carbs work fine, so that's good.

also we could adjust the float level very good this way.

but still... first carb leaks gas at the throttle valve shaft.

the other leaks were all at those aluminium plugs at the top, i fixed those today. moving on.

what do you think about the 3rd valve flipping up and down?

Edited by Cpt.Fred
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Looks like you might need to do a compression test on theo back two cylinders. May be you have a sticky vlave from having the engine sit around over the winter.

I assume you don't have a place to attach a vacuum gauge. But see what a compression test shows.

I don't think you want the jumping around like that. I would set the float leves quite a bit lower that stock, shouldn't be a problem of starvation as each carb only really needs 1/3 of what would be the single carbs volume.

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couldn't i attach the gauge to the carb's vacuum port?

or do i absolutely need manifold vacuum to do that?

about the vibration, we found the carbs are going through a lot of unnecessary shaking,

so we will build a support for the manifold using the head bolt that originally carried the old air cleaner support.

otherwise we'd have to deal with fatigue breakage of the intake due to the vibration sooner or later.

about the float level, i thought it would need to reach this gap here to

guarantee correct operation of the accelerator pump?

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i will borrow a compression tester this afternoon from a friend.

i am also wondering why i cannot lower the idle to a normal level... right now it's around 1000 to 1200rpm, i guess...

i managed to get to about 700, but that was it. hmmm....

Edited by Cpt.Fred
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What you are pointing to is actually an overflow, the feed for the acc pump is the cast groove in the bottom of the float bowl. So the level can be below that slot.

You can attach a gaube to the carb port, but that will show you ported vacuum which is generated by air flow throughthe carb. It is actually intake vacuums opposite.

When vacuum is high through the carb, intake vacuum is low, as in WOT acceleration,

Intake vacuum is high at idle or sustained moderate speed.

So you would only get a significant vacuum signal from a carb port when asking for more power of speed from the engine.

Remember the vacuum signal from the manifold works to keep the step up closed at idle, and or cruise, the lessened signal at WOT allows the spring to open the jet to provide the extra fuel for the load. Theother side of the coin is that increased ported vacuum from the carb, when opening the trottle, pulls on the vacuum chamber to anticipate the ned for spark advance.

So ^ vacuum at the manifold = low vacuum in the carb, ^ vacuum at the carb = low

vacuum at the manifold. 2 sides of the same coin.

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couldn't i attach the gauge to the carb's vacuum port?

or do i absolutely need manifold vacuum to do that?

about the vibration, we found the carbs are going through a lot of unnecessary shaking,

so we will build a support for the manifold using the head bolt that originally carried the old air cleaner support.

otherwise we'd have to deal with fatigue breakage of the intake due to the vibration sooner or later.

about the float level, i thought it would need to reach this gap here to

guarantee correct operation of the accelerator pump?

i will borrow a compression tester this afternoon from a friend.

i am also wondering why i cannot lower the idle to a normal level... right now it's around 1000 to 1200rpm, i guess...

i managed to get to about 700, but that was it. hmmm....

When I first set mine up I also had a high idle. I ended up closing off the front and rear carbs during idle and they open up right off idle. I can do this because of the log type set up I have. Also the leaking at the throttle plates I had too. I put a fuel pressure regulator on and eliminated that problem.

Hope some of this helps.

Looks GREAT!!!

BloodyKnuckles

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