201 hop up project

[Cpt.Fred]

good point indeed...

i stayed close to my manual and retorqued after the first ride,

on hot engine. i was surprised how much i could move them.

but i didn't repeat that because honestly i was afraid to kill the bolts

if i tightened them too hard, or to warp the head...

well, i got a new compression tester yesterday and i'll check the engine this evening.

let's hope i just blew the gasket and didn't frag any valves...

thanks for the tip!

[P-12 Tommy]

Don't screw the adapter too far in the spark plug hole to test compression! Been there, done that!

Tom

[martybose]

Don't screw the adapter too far in the spark plug hole to test compression! Been there, done that!

Tom

And if you have both a short and a long adapter, use the short one!

(Corollary to the above)

Marty

[Cpt.Fred]

first of all:

i didn't bend anything, my tester works fine (checked that before bolting the shaved head down, because i was told to do so on here earlier, so thanks!)

funny thing is, i have between 115psi and 120psi on all 6 cylinders... this is even better than it was on the first test!

so that's a good thing for start. the head can stay on there.

so the culprt is either one (or all three) of the carbs or timing

is going nuts for some reason...

since we all get flooded here for the last few days (rain, rain, rain, more rain)

i guess i will go on next week.

OT...

another good news: my scooter's engine got a good makeover, too.

now i can finally ride it again, so much fun!

picture from last year's camping trip:

[greg g]

Is the scooter a Zundapp? What year. Didn't know you were "scooter trash" as they say over here.

[Mark D]

Awesome scooter!

[Cpt.Fred]

scooter trash, hehe. that's good.

it's an IWL SR59 Berlin from 1959.

IWL means "Industriewerke Ludwigsfelde", SR means "Stadtroller" (city scooter),

59 is the year of introduction, and "Berlin" is the name of the model.

you can see the lettering and city arms on the right front of the shield (or what is that called in english?)

typical east-german 2-stroke dinosaur

the engine is a 9,15 cui single cylinder developing something around 8hp, enough

to cruise 50-55 on country roads.

edit: just looked at the papers, it's a '60, not '59

Edited July 4, 2011 by Cpt.Fred

[greg g]

the front fender and suspension looked a bit like a Zundapp, but Now I see the rear body lines are different. Looks like fun.

Here is the Zundapp (bela) I was thinking of

Which way do you seperate the word Stadtroller cause is you break it after the "D" it becomes Stad troller as in trolling or cruising for chicks...........

55mph ugh no thanks, a few year back my wife and it took a trip out to the western states to visit some national parks. Going through Nebraska we encountered a whole group of folks on scooters going the opposite direction, probably 30 or 40 of them, all loaded down with gear and spares.

Apparently they were involved in a long distance ride (3500 + miles) or so.

I believe this was it, and it look like it runs every 2 years so make plans for 2014

http://www.scootercannonball.com/results/2006Updates.html

So get it done up and come on over

http://www.scootercannonball.com/

[Cpt.Fred]

of course you're right, greg, those 50s and 60s scooters all look pretty much the same

(except the harley topper:rolleyes:)...

but i must say i like the Berlin's lines very much and it is a good and reliable machine.

most important, it's still quite cheap to own one, those Zündapp Bella,

Heinkel Tourist, Piaggio Vespa or Lambretta scooters all cost a fortune

and you don't get spare parts that easy.

the Berlin is just a motorcycle in disguise, engine, drivetrain and lots of other parts are basically the same as the MZ RT 125 (former DKW),

though they enlarged the engine a little.

and if you like trolling... get a load of this:

http://www.weickert-online.de/assets/images/troll1.JPG

the mighty IWL Troll (Touren Roller)... ugly as no other:D but fast.

that cannonball race looks fun, though. i have to talk to some friends here...

BTT...

Still wondering what could cause that much power loss and back firing on my flattie. Guess i open the carbs, check for damage in there and try putting the timing back to TDC for a start.

[greg g]

Have you tried taking a vacuum reading??

[Don Coatney]

I wonder how many Cushman scooters were on the Cannonball Run?

[Cpt.Fred]

i got to perform some more tests yesterday

and finally took a vaccuum reading on all three intakes simultaneously -

a good friend has a testing unit with 4 gauges for his motorcycles, great stuff...

all three carbs are acting equal and pull a very strong vaccuum.

then again i was asking myself, since there are balance tubes now,

doesn't that falsify the readings on a single carb? because the others sort

of "help" if one isn't pulling enough vaccuum?

hmm...

please correct me if i'm wrong.

it was funny anyway, because when we wanted to start the engine it didn't fire up at first,

which is very unusual on this one, and when it ran it was idling very smooth, surprisingly,

because it ran like s*@t when i parked it about 2 weeks ago...

when we tested the timing again we used a tachometer this time and had a look at what the advance was doing when we would rev up the engine.

idle is currently 550-600rpm, that's as low as i want to go because lower usually kills the engine when i come to a quick stop at a light,

or when i open the throttle too jerky. is that still too high or just right?

the tests were done with disconnected throttle vaccuum on the vac advance.

i'm running 6-10° spark advance (it's a little hard to read on the pulley),

because when i run too conservativly (TDC like in the manual) i feel like the engine is a bit muffled and doesn't run too good.

but: when i raise rpm to about 1000, the advance has already nearly left the scale!

above 1500 massive backfiring starts...

we did a road test without vac advance and my friend asked me to step real hard on it to reach high rpms.

that wasn't easy for me because the car sounded like a shot down fighter plane and i really feared blowing the engine, but he was right:

when we reached high rpm ( i guess round about 3000-3500?? don't know exactly) the backfiring ceased and it began running smoother.

i had to stop than, because we were in city limits

so our theory would now be that the centrifugal advance is acting too agressive on low rpm. what do you think about that?

i'm going to change the condenser as well, though it's not even a year old, but i my friend thought i should try.

but i guess ignition is the culprit here, no matter what part exactly.

i would love to hear your thoughts on this!

best,

fred

by the way, should i stop this and open a new thread or is it ok if i go on here?

Edited July 13, 2011 by Cpt.Fred

[Don Coatney]

Fred;

I think it is good to keep this thread so all the information is in one place.

Follow this link for information on how to correctly set up your vacuum advance.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=7564&highlight=advance+curve

Also I would set your mechanical advance at no greater than 5 degrees advance. Read these two threads for the reason why.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=2198&highlight=knock

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=2341&highlight=knock

One other issue is with the vacuum set too high engine overheating may occur.

[moose]

Hey Fred,

I agree the distributor may be the culprit. What number is your distributor? I may have a replacement for it in my stock. If so I could set it on my distributor machine and send it your way.

so our theory would now be that the centrifugal advance is acting too agressive on low rpm. what do you think about that?

i'm going to change the condenser as well, though it's not even a year old, but i my friend thought i should try.

but i guess ignition is the culprit here, no matter what part exactly.

i would love to hear your thoughts on this!

best,

fred

by the way, should i stop this and open a new thread or is it ok if i go on here?

[Cpt.Fred]

Thanks for the links, Don! I'm going to read that carefully.

Especially important because i do not have the original washers

for the retainer spring of my vac advance anymore,

so i don't know if it's acting like it should.

but since everything kind of worked for a while,

there should be more other stuff that stopped working...

Moose:

sounds good, my dizzy number is IGS-4109-1.

someone told me this might not be the original part for a 201, i don't know.

i'll pm you for further stuff, a new distributor might be good anyway.

everything a little shaky in there, though i had it apart, checked all the cables and oiled it up.

[moose]

My book shows those numbers as for a 1940 Plymouth 6: P9-P10

I'll check what I have later today. I probably don't have that exact one, but we could work something out, I bet.

Moose:

sounds good, my dizzy number is IGS-4109-1.

someone told me this might not be the original part for a 201, i don't know.

i'll pm you for further stuff, a new distributor might be good anyway.

everything a little shaky in there, though i had it apart, checked all the cables and oiled it up.

[T120]

sounds good, my dizzy number is IGS-4109-1.

someone told me this might not be the original part for a 201, i don't know.

i'll pm you for further stuff, a new distributor might be good anyway.

everything a little shaky in there, though i had it apart, checked all the cables and oiled it up.

..Don't know if this is useful info for you or adds to the discussion, but it appears as though the advance curve for the IGS-4109-1 and 4111-1 also the 4204-1 are the same

..(dist rpm 1/2 eng rpm)

[Cpt.Fred]

cool, so i do have the original one. i email you tomorrow.

thanks for the chart, Ralph!

[Cpt.Fred]

hey Don,

thanks again for the link, the one on the vac advance is really helpfull.

as i wrote, i too just put a random amount of washers in there... so i guess i get myself a vac pump here and do some testing.

anyway, i have one more question, because the thread ended there without a real solution...

you wrote:

"The vacuum advance comes into play only while accelerating. Once at speed it does nothing."

martybose wrote:

"The OEM connections were straight manifold vacuum, so there would be no advance when you were on the throttle and accelerating,

but you would have the advance when the throttle was mostly closed and

cruising at a steady speed. Having the advance generally improves gas mileage, but you can't run that much advance under full power."

can it be that you both meant the same thing?

or is there a mistake, because on my engine the vac advance feeds from throttle vacuum, and the manifold vacuum only powers the wiper motor.

here

and here

when i recall correctly, manifold vac collapses as soon as the throttle plates flip open (thus limited wiper operation when you pass for the lead...),

while in return throttle vacuum is high on WOT operation and low when the plate is closed.

is that true or do i mix up stuff once again...?

Edited July 14, 2011 by Cpt.Fred

[greg g]

The ported vacuum signal and the intake signal are actually opposites. Carb vacuum is reacting to increased flow throught he carbs under acceleration or WOT, monifold vacuumdrops during acceleration and ironically both are at play during acceleration

Ported vacuum because it increasee timing advance ahead of anticipated timing needs, the manifold signals drop, allows the power valves within the to open to provide additional fuel after the initial shot from the acc pump circuit., as the intake signal increases when you let off the gas it closes the intermediate valves, and ported vacuum deminishes retarting the timing for cruise mode.

Hope that doesn't muddy the waters but that how it works on mopars.

Some chevys use manifold vacuum for timing but its a different system. The reason a lot of chevy guys run without vacuum, is that their dist are set up to react to centrifigul machanical advance. So for Drag racing where total advance is wanted for what is basically a WOT all the way run, the vacum signal from the intake is reduntant to that need. It does work for WOT operation but does not make a very driveable street car setup.

[Don Coatney]

What greg said should answer your question. Marty is using a Chevy distributor and his setup seems to work using manifold vacuum. However others who use the same chevy distributor have had good results using ported vacuum. But as you are not using a chevy distributor yours should work well with ported vacuum. Your application of random washers will work using a vacuum pump to test and make adjustments.

[martybose]

What greg said should answer your question. Marty is using a Chevy distributor and his setup seems to work using manifold vacuum. However others who use the same chevy distributor have had good results using ported vacuum. But as you are not using a chevy distributor yours should work well with ported vacuum. Your application of random washers will work using a vacuum pump to test and make adjustments.

It really depends on how modified your motor is. Mine is fairly well modified, and I started using manifold vacuum instead of ported vacuum when I started experimenting with different carbs. I did this with a stock distributor, way before I tried the HEI.

What most people miss is that with the stock single carb and ported vacuum you reach a point where higher speed necessitates more throttle, and with the ported vacuum you get a lower signal, retarding the ignition at higher throttle. Effectively with ported vacuum you get no advance at idle, strong advance at small throttle openings and less advance with larger throttle opening.

Anyway, I'd try both, and see which one works best for you.

Marty

[Cpt.Fred]

thanks!

all modifications on this engine can be found in this thread,

.040 milled head, triple carb setup, equal lenght full split headers.

nothing too fancy, so i guess i just stay with my vacuum setup

as it is.

i hope the test runs with lambda sensors will shed some light on this case...

[Cpt.Fred]

ok, this is a little embarrassing...

we installed the CO testing unit yesterday.

before that i started the engine and it ran very bad again.

only this time i checked if all the header tubes would get equally hot...

and they didn't. so i found out that the spark plugs on cyl 3 AND 4 (!!!)

would fail from time to time. when i hit them with a wrench they came to life,

only number 3 failed again after a minute...

so i took the plugs out and put new ones in there (these were new, too. i put them in there when i mounted the head roughly a 1000km ago).

great quality, thank you very much, sir.

the backfiring still continued, though.

i took the distributor out and took it apart to check for broken springs.

nothing. they might be a little tired, but nothing is wrong that one could see with bare eyes... so i assembled it and put it back in for now.

we then did a CO test and noticed the mixture would lean dramatically everytime i hit the throttle. so it appeared the backfiring wasn't really timing related

but due to a fuel shortage!

i took the tops off the carburetors to have look what's going on inside and i found that crud from the fuel tank had somehow managed to pass 2 filters

and the electric pump to gather in the float bowls and block the main passage.

i know someone who will take his gas tank out and give it a good cleaning...

it might be smart to take the carbs apart once again and clean them with compressed air, i guess.

i cleaned the bowls out, changed filters once again (they looked clean but what do i know??) and let the engine run: backfiring was history.

nice observation on the side: all three step up jets are down and stay down at idle.

afterwards we did a few road tests with the lambda unit.

result:

idle is too rich, WOT is too rich, but acceleration seems to be too lean.

i turned the idle screws in as far as it is possible without killing it, it's still a little rich but that's ok. results in a great starting behaviour, i guess.

i will play with the acc pump levers the next time and then we'll see what happens.

this story shows once more that if i can choose from either ignition or carburetor troubles i ALWAYS pick the wrong one.

...and that i tend to panic, of course.

i will, however, not forget about the strange behaviour of my centrifugal advance. maybe i can put a stronger spring in there or i get new ones somewhere?

we'll see.

more test runs.

that CO tester is the greatest little toy i ever got my hands on.

[Cpt.Fred]

few pics of the CO tester (have to share):

just hook up 12V and it's good to go.

i hope i make it to the dirt track race this weekend...

500km in total. i'll disassemble the carbs today and blow them clean,

and if i have time left i take the tank out.

i guess it's only bolted to the floor with two straps?