Help needed with Aero 50

fbergski · Post by **fbergski** » Tue Sep 27, 2005 8:06 pm

Here's the problem. Just got the Aero back together and I cannot get it to run decently. I broke the bystarter on the original carb by accident and substituted a good carb off a 84 Spree, changed the main jet also. I replaced the pistons rings and put it all back together.

Bike starts decently but runs doggy after that, the bystarter seems to work ok because I checked per the Spree service manual. If I remove the vacuum line to the fuel valve it runs better. What's weird is it's spitting air/fuel back out the carb when it runs. I thought maybe I had the reeds in upside down but after looking at the intake manifold they only go in one way. The idle mixture screw is backed way out also for it to run.

I'm pulling my hair out on this one, exhaust seems to be good, steady stream of smoke when I give it gas. I did take the oil pump cable off, could it be getting too much oil? I've disassembled the carb like three times now and see nothing wrong, all the passages are free. Float and needle appear to be working fine also.

If I adjust the needle it doesn't change a thing, I have it one lean right now. When it runs it will run smooth then the whole engine shakes and it smooths out again?

Help me PLEASE!!!

Philip

MySpree · Post by **MySpree** » Tue Sep 27, 2005 9:16 pm

spree carb that is all. maby thats itt?

Post by **noiseguy** » Wed Sep 28, 2005 11:38 am

What year Aero are you running? Are the Aero and Spree throat diameter's the same (smallest diam of carb.) What jet are you using?

Is your idle jet clean on the Spree carb?

Reconnect your oil pump cable. That thing increases the oil you get at WOT, so you are actually starving the engine for oil, not overoiling it, unless you locked it in maximum open position. Read up in the tech docs on this.

Sounds like you're running rich, if creating a vacuum leak helps. Too large a main jet, perhaps? Needle valve off adjustment?

fbergski · Post by **fbergski** » Wed Sep 28, 2005 2:35 pm

Oil cable is connected. Carb is clean and all passages are open. I installed the main jet from the Aero carb into the Spree carb. It's possible the carb that was on the Aero when I got it was incorrect. I noticed that the previous owner had messed with it.

What size jet should I have?

Philip

vette76 · Post by **vette76** » Wed Sep 28, 2005 2:50 pm

65 68 is fine too.

Post by **noiseguy** » Wed Sep 28, 2005 3:13 pm

Those are good Spree sizes, I'm guessing that the Aero would be about the same....? Post back with your sizes. Some ppl like to upjet their Spree for no good reason. It usually just wastes gas.

I'm always nervous working on something that someone else has been into. The dead Spree I'm working on had the starter bendix resassembled wrong (don't know why it was apart in the first place.) That was fun to fix.

fbergski · Post by **fbergski** » Wed Sep 28, 2005 11:51 pm

Problem solved. Replaced the Spree carb with the Aero carb and it runs fine, jury rigged a temp solution for the broken bystarter.

Philip