MOPED ARMY

Ok one more thing - opened the new plug and it was a little white on the top, and black oily fluid around the outside thread and head. Any ideas now?

I cleaned the air filter, so i know that it is not the air filter causing the problem.

However, I do think it has something to do with this one screw on the carb, which i've turned and adjusted, but haven't found the right mixture? Theres only one main screw on the carb that looks adjustable, i believe this is the screw that regulates the air coming in. I've adjusted this to different # of turns, but still the moped stalls sometimes.

Please Help, thanks

check the main jet for blockage.Jim

its definetly not your air filter. you mentioned it runs better with the choke closed and that your plug is white. that means it is too lean. the carb or something in the fuel system is partially plugged up, or you have an air leak. i'm betting your carb is dirty inside.

Oh and check the points gap and clean them...

Ok guys thanks for all the replies so far...

I tried starting my moped up this morning, and it started real quick. I put the choke down, and the moped accelerated fast.. I took it on the street and was going like 30 mph until i slowed down to take a turn and it stalled.. I noticed the choke lever was up by this time.

I have some questions about a few of the replies, but will first tell you what ive done to the bike to get it running:

-I cleaned out the gas tank with a phosphoric acid mixture, and flushed it out, then filled it up with new gas/oil mixture.

-I took the carb apart and sprayed it with a carb cleaner all throughout the insides... (i didn't poke holes with a paper clip or clean the main jet*)

-I installed a new spark plug (but i noticed a white residue on the spark plug after running the moped for a while)

Questions:

-How do I decoke the piston top, cylinder head and exhaust port? (in response to crisis)

-How do i check the points gap and clean them? (in response to crisis)

-I've located one adjustable screw on the carb, that if i adjust while the moped is running, it seems to idle the same, but give a different response to the throttle. (this is either the gas/air ratio screw or the idler screw, im not sure which)

Im thinking its the carb and im gonna take it apart today and clean the main jet and try to poke holes with a paper clip...

If it starts and is running your points are probably cool, but to check the points gap or clean the points you remove the magneto cover. The points are under the magneto. When the piston is at top dead center the points should be all the way open at whatever the points gap should be for that engine... I don't know off the top of my head what it is for your minarelli. To clean the points you bring the piston all the way back so that the points are closed. then pry them open and place a piece of 600 grit sand paper folded in half in there. Then let the points close on it. Then drag it out. Do this like 10 times... This is usually done only when you don't have good spark or no spark, so it's probably not going to fix your problem... To decoke the piston crown, head and exhaust port basically means that you scrape the carbon that is built up on the piston crown, head and inside the exhaust port off. I usually use a thin flat head screw driver. Just be careful not to gouge it or make any deep scrapes on the piston crown or head, since they are alluminum... If there is a screw on there besides your throttle screw, it's usually an air mixture screw, which will only effect your throttle response at idle. It basically controls the air/fuel mixture at idle... To me it sounds like you need to really clean your carb and make sure there is nothing in the main jet...

most often when a crankseal goes bad an engine cannot maintain idle because it cannot hold the vacuum or the pressure needed for proper fuel/air flow.

and it's a bitch to start...

My moped had a rusty gas tank and keep cloging up my carb on my old Vespa other then that it works like new. :)

Restart your process by using the Repair Forum and the very first thread—that’s about the wiki and Fred’s guide. You’ll frustrate yourself and others as long as any important steps (variables) are left out or checks are not performed. Get to know your engine and a bit of detail, helps a ton to know you have a Minarelli V1 with a Dellorto SHA carburetor (right?). That helps you drill more deeply into the wiki for more intensive troubleshooting. Rule out basics like the seal at your intake by just replacing the shim and o-ring type gasket. Totally clean carb plus those items could eliminate important variables. The time you spend is worth it for your peace of mind, but also gets you better advice here. Hang in there and post again when you make some progress.