LX, Bogs down!

Michael Romano /

Well, i just rebuilt the topend on my tomos targa lx. I port and polished the cylinder, and ground out the intake and a few other things... Well when ever I ride, It is almost a task to ride due to me having to hold in the choke 90% of the time while I ride. I have to Hold it to start and then when i get to about 10 mph i let the choke go and it hits 2nd gear and i have to hold the choke In again and it wont rev at all without holding the choke and if i try to with out the choke it sound like its flooding... Ne body have ne clue what the problem could be... I would love some advice ... I also did a plugchop today and the plug looks almost a red color like rusty, that was after a nearly 7 mile ride!

Michael~

Re: LX, Bogs down!

Don Pflueger /

the idle circuit in the carb is plugged up.

Re: LX, Bogs down!

Michael Romano /

Are you referring to the idle jet? What about my air filter, Could a more restrictive Filter Work?

Michael~

Re: LX, Bogs down!

Don Pflueger /

probably. do you have a filter and air box on it?

Re: LX, Bogs down!

Steamboat Aka J. R. Stevens /

Donp, is that 7 mile run good for a plug chop? jim

Re: LX, Bogs down!

Don Pflueger /

it would be fine if he only ran at full throttle for 7 miles and did not let up at all. but about a mile is all that is needed. the key is to run full throttle and not idle, and shut the engine down at full throttle then close the throttle and coast to a stop.

so in my opinion his plug chop is not right. and ive never seen a redish colored plug myself so i dont know what that could mean. too hot maybe? inncorrect heat range on the plug?

Re: LX, Bogs down!

If this all started after modifying the ports the engine is probably just 4-stroking .. at low RPM in first gear.. shift to second and the engine RPM drops low again..

This low RPM flooding happens because the intake port is open for a while when the piston is traveling downwards.. fuel mix already inside the crankcase gets pushed back up into the intake manifold and through the carburetor at low RPM.

This recycled mixture then picks up another load of fuel (or two). The now triple-rich mixture causes misfires. Closing the choke probably just creates an obstruction to this backward pumping action and allows the engine to keep running..

When the engine speeds up, gases pick up speed too, and the inertia of the fuel mixture then prevents the piston from pushing it backwards.

There is a fine balance between maximum intake port timing and adequate low RPM performance... beyond that point you get very poor low RPM performance.

Re: LX, Bogs down!

Michael Romano /

Well i have an air filter, but all it is is a cheap lawnmower one from home depot and i had to cut the plastic on the filter to fit it on the bike... Now It idles at nearly 30 mph and the idle screw is all the way out. But i noticed if i took the filter off and placed my fingers over the air intake with just a small hole, that the Idle drops to normal!

Michael~

Re: LX, Bogs down!

a redish color indicates either a form of a cleaner like carburetor/injector cleaner or condensation in the cyclinder.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account