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JeanFabricio

[HELP] My LI problems / BRAZIL / Energy / Environment

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Hi guys.
I have an 1966 brazilian LI (http://lambretta.org/message/viewtopic.php?t=15540)
And I also have a very bad english... so I'll try to describe the problem.

The LI came with an original Dellorto carburetor. But it was troubled that I could not fix. So we installed a Jetex carb.

The engine is good, magnet and all the electric parts are also good - some parts are new. The LI has 900 km since the engine was rebuilt.

But it has a problem: when I start the first time in the day (2°C or 20°C), it usually start at the second try.

But if I ride, no matter how long or how far away, and turn off when I turn it back on after 5 to 40 minutes, it does not start. I've tried everything: choke, throttle position, inclination, in the sun, in the shade ... and I can not figure out why this happens.

The jet (I believe that is the part name) was changed yesterday from 115 to 105, but today it "died" in the street... and took 30 minutes to start.

I'm almost loosing my leg!!!!!!

I don't know what else to do ... can anyone give some idea, even if it is an idea too crazy or too stupid?
Thank you.

 

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J-F,

 

the Jetex has a different setting for the air-mix screw. try it at 3/4 of a turn out, not the normal 1 1/2

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try as above - but next step would be to get rid of the Jetex carb. Very problematic and do weird things.

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try as above - but next step would be to get rid of the Jetex carb. Very problematic and do weird things.

 HAHAHAHAHAHAHAHAH

 

Yesterday I found a Dellorto Sh 18, the original model. I clenned up all the carb and today I let the carb in a shop to do tests. If it works, I'll get rid of the Jetex. But if it don't works... :(

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I have two perfectly operating Jetex22's. One is currently on the jet200. The 18 would be better suited.

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What octane?

regular (here we call "comum"): 87

"super" (here we call Podium, from Petrobras): 95.

 

I use only regular with a 4% oil mixture.

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That high mix of ethanol has much lower energy content than gasoline, and it needs a different air amount to burn.  Gas burns at 14.7:1 vs the 9:1 for ethanol.  Your mix will burn at 13.3:1.  Since you can't do much for your air metering, you probably need bigger jetting than stock, not smaller.

 

You might try closing your spark plug gap a bit, ethanol is harder to ignite than gas.

 

I'm just going on the fuel properties, we have 10% ethanol in California, but 25% is a different thing altogether.

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That high mix of ethanol has much lower energy content than gasoline, and it needs a different air amount to burn.  Gas burns at 14.7:1 vs the 9:1 for ethanol.  Your mix will burn at 13.3:1.  Since you can't do much for your air metering, you probably need bigger jetting than stock, not smaller.

 

You might try closing your spark plug gap a bit, ethanol is harder to ignite than gas.

 

I'm just going on the fuel properties, we have 10% ethanol in California, but 25% is a different thing altogether.

 

 

HI jheadley.

I don't understand some things:

 

- "advancing your timing a few degrees" - ???? I don't understand! Do you have a picture?

 

- "closing your spark plug gap a bit": do tou mean the space that I circle in the picture above? (not this much, of course...)

RgIEwf.jpg

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 HAHAHAHAHAHAHAHAH

 

Yesterday I found a Dellorto Sh 18, the original model. I clenned up all the carb and today I let the carb in a shop to do tests. If it works, I'll get rid of the Jetex. But if it don't works... :(

If the SH18 doesnt resolve the issue - then the ignition system is the next place to look as menstioned. If you plan on keeping stock or slightly  modified maybe one of these carbs might be the order of the day. Probably expensive to get to your parts - but may be worth it. As for the ethanol issue - maybe a nice electronic conversion would give you a stronger spark needed to burn ethanol along with the addition of this. Good luck!!

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I have two perfectly operating Jetex22's. One is currently on the jet200. The 18 would be better suited.

You got lucky and got 2 assembled by the right Indian kid !! The one I have will be getting smashed with a hammer so it doesnt end up in anyones hands!!!

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HI jheadley.

I don't understand some things:

 

- "advancing your timing a few degrees" - ???? I don't understand! Do you have a picture?

 

- "closing your spark plug gap a bit": do tou mean the space that I circle in the picture above? (not this much, of course...)

RgIEwf.jpg

 

For the spark plug gap, yes, you are correct.  You can try reducing the gap, I run mine at 0.018 inches which is 0.46mm.  You might even go as low as 0.016 inches or 0.41mm just to see if it helps.  If you have electronic ignition, you should not need such a small gap but it's worth a try.

 

For setting the timing, you must adjust your stator position to open the points earlier before the piston reaches top dead center.  Here is an example page that shows what I mean:  http://www.scooterhelp.com/tips/timing/points.timing.html 

You might want to set your timing a couple degrees earlier than it currently is, but you must be careful not to go to far or you can cause problems with detonation.

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Hi.

 

The more I read, the more I remember things.

First of all, my LI has no battery. And the magneto is rebuilt. The coil is 12V. I used 3 6V coil, but all "broke". The magneto is very strong, and finally the 12V coil works.

 

ALEXOFC69, thanks. I save the link of the Dellorto carb. The electronic ignition kit is terrific, but is very expensive. Here our govern has a tax of 60% on imported stuff. So if the kit is 425 box and the S&H is about 75, the tax is 60% of 425+75... Here there's a guy who built a home made eletric start, but he built only to him... :(

 

jheadley, adjust the timing seems complicate... but if anything works, I'll try.

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You might need to lower compression to deal with that much ethanol in the fuel. Ethanol attacks and dissolves / corrodes most rubbers, plastics, and many metals, including the metal the carburetor is made of. I would also run a 2 stroke oil made from esters as these seem to do a little better in ethanol laced fuel.

 

Now for the politics, 'cause I am in Warsaw and see that most people in Poland want to emulate the Americans and drive huge, fast, gas guzzling cars. There is no talk of conservation of fuel resources. Hell, I would support fuel rationing. We need to seriously reduce the rate at which we burn fossil fuels and the only way to do that without giving up our private transportation is to force lower fuel consumption, not dilute gasoline with agra fuels that cause high food prices and shortages and on a global scale, do the opposite of what supporters claim.

 

Your ethanol comes from sugar cane that has replaced the rain forest that was cut down for the plantations. This creates a net carbon increase in atmospheric CO2.  It's better to just burn pure gasoline and mandate small, efficient engines in cars so we burn far less of it as we are doing now as we make the move to electricity as a main motive fuel. In the USA, as unpopular as it was in 1971, the banning of manufacturing of high performance muscle cars and the introduction of corporate average fuel economy standards for car manufacturers reduced to a greater degree atmospheric CO2 output from cars than just about anything since then, with the exception of severe economic recession.

 

To the USA I say, screw the V8s and other huge engines and heavy cars and SUVs. These things should be legislated out of existence. We can have fun on our scooters, instead.

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You might need to lower compression to deal with that much ethanol in the fuel. Ethanol attacks and dissolves / corrodes most rubbers, plastics, and many metals, including the metal the carburetor is made of. I would also run a 2 stroke oil made from esters as these seem to do a little better in ethanol laced fuel.

 

Now for the politics, 'cause I am in Warsaw and see that most people in Poland want to emulate the Americans and drive huge, fast, gas guzzling cars. There is no talk of conservation of fuel resources. Hell, I would support fuel rationing. We need to seriously reduce the rate at which we burn fossil fuels and the only way to do that without giving up our private transportation is to force lower fuel consumption, not dilute gasoline with agra fuels that cause high food prices and shortages and on a global scale, do the opposite of what supporters claim.

 

Your ethanol comes from sugar cane that has replaced the rain forest that was cut down for the plantations. This creates a net carbon increase in atmospheric CO2.  It's better to just burn pure gasoline and mandate small, efficient engines in cars so we burn far less of it as we are doing now as we make the move to electricity as a main motive fuel. In the USA, as unpopular as it was in 1971, the banning of manufacturing of high performance muscle cars and the introduction of corporate average fuel economy standards for car manufacturers reduced to a greater degree atmospheric CO2 output from cars than just about anything since then, with the exception of severe economic recession.

 

To the USA I say, screw the V8s and other huge engines and heavy cars and SUVs. These things should be legislated out of existence. We can have fun on our scooters, instead.

 

Kevo, I understand everythig. But all that "ecological" stuff are bla bla bla here. Just for the TV and ads.

 

I have a way to "take off" the alcohol of the gas and works very well (but do a giant mass!!!!): 1/2 liter of gas in a Coca-Cola bootle. Put 1/2 liter of water. Shake very hard. Let rest about 30 minutes upside down. The water and alcohol get together, but not the gas. Open just a little bit and let the water flow... slowly... only gas will rest in the bottle.

Retirar+Alcool+da+Gasolina.jpg

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PLEASE DO NOT PUT GAS IN A COKE BOTTLE AND SHAKE IT.

 

THAT'S RECIPE FOR A DISASTER.

It is a very bad idea, and could have very disastrous consequences.

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As the ethanol in ethanol blended gasoline is used to raise the octane rating, removing it leaves you with very low octane gasoline. What you did was to cause phase separation. Ethanol is added to gasoline when the fuel trucks are filled at distribution points. This is to prevent the gasoline stocks from going stale within weeks of storage. So you might want to look for an octane booster to add to your fuel once you've taken the ethanol out. I would still try lowering the compression (by enlarging the combustion chamber of the cylinder head) or retarding your timing to 17 or maybe 16 degrees before top dead center (BTDC).

 

Btw. it's not just ecological blah blah blah, as you say. It's a serious issue and it will become more and more so, leading to political solutions that may come down hard on us owners of vintage machinery. I know I'm an outsider and as such it might be none of my business, but I gotta ask you how your politicians allow so much of your rainforest resource to be cut and burned down? That happened in my home state in the mid 1800's, but the forests were replanted by 1900.

.

I should add that as an American I am dismayed, ashamed, and angered by what my country has done and continues to do, emitting more greenhouse gases than any other country, especially as measured per capita. By riding our scooters more and driving our cars less, at least us scooterists are mitigating the problem but in a very small way due to our very small numbers compared to the general population.

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back to the original question, jean, try something very simple before you go fiddling with things. turn the choke off, hold the throttle all the way open, and kick 10-20 times. if the bike starts this way, then your problem is probably a little bit of flooding. this is VERY common. if this is the case, then next time you ride, try turning the fuel tap off a few seconds before you stop the engine. sometimes this makes it a lot easier to start back up when warm!

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