80 c.c runs best on half choke..whats wrong ?

[misteright1_99]

Cutting the rod doesnt make that much of a difference except for noise... You want performance after you get strait, take off the exhaust and look at the gasket, cut it so the opening matches the opening in the exhaust port in the cylinder, then carefully take it off and hold it up to muffler and see how far they are off. Same with the intake. Grind the muffler and intake to match the ports in engine, and you will get increased performance... But thats at a later date. Look at that post I sent you.in PM....

 

[misteright1_99]

Mister right
You beat me to it.
I guess i type to slow LOL.

well my lunch is over i'm going back to the shop.

Bob

Sorry Bob Im semi retired got nothing but time......

 

[BlueCollarBikes]

well since I know its not a air leak probelm..and adjusting the needle clip fully to the bottom position didnt fix it, then I will have to take it apart......

I wonder if cutting the rod inside the exhaust down to 2" would be causing this ? Unfiortunately, I did that mod first.....before running the engine with the totally stock muffler.

I would guess no.


So your saying
no air leaks
( carb is tight and pushed all the way into the manifold , manifold flange was inspected for rough edges,and manifold gasket is tight with no leaks.the slider throttle housing is not cross threaded and tighten correctly,
.
And jet is clean of goodies. and oil gas mixture is correct.
and Compression is good .


bob

 

[BlueCollarBikes]

Sorry Bob Im semi retired got nothing but time......

I'm retired as well But i can't seem to stop working.LOL

Cheers

Bob

 

[misteright1_99]

20 : 1 mix.....7 ozs to a gallon using MC1

I didnt clean out the gas tank cause I didnt think it was neccessary and becuase my manual said there are 2 filters pre carbertour...one in the petcock and one in the inlet of the carb.......

I guess ill take it apart.....:{ I think I may have some feeler gauges that are the round circular kind...and I could use that to go thru the jet....

That mix is more like 18:1 but that is good. My tank was just filled with rust, flakes, and garbage, and even after cleaning it out, my filter still plugged up 2 weeks later....

 

[rumme]

well I just spent 90 minutes working on the carb..

took it apart.....nothing looked out of the ordinary...the float system on mine isnt attached to the float rod like older motorcycle carbs.....kinda neat...

anyways....the jet wasnt clooged...no massive dirt or metal filings in the carb....and the long needle valve looks like it has a slight taper but I did go ahead and hit the bottom of the rod with some emery cloth about 15 rotations...just enough to take the dull brass look off of it and now its shiny....


I put it all back together...moved the needle clip back to stock middle position....did the same thing...had to keep choke in about middle position for it to run decent and not bog down when givign it throttle..

moved the clip to its lowest position....no change.....runs best with choke pulled up about half way....if I pull choke up all the way, it immediately stalls out.....

no air leaks at the intake......but there is a very slight bit of oil around the exhaust port where the muffler bolts on....not alot.....the gasket between that joint is a carboard one sandwhcihed in between two flat copper looking gaskets ......fitted together to make one whole gasket....looks more stout then your normal cheapy all cardboard style gasket

does anyone else have any ideas whats going on ? If not, im just gonna have to ride it with choke about half on all the time.....

 

[rumme]

maybe I need to drill out my jet ? or buy another one.....about 35 miles from me there is a motorcylce place....they might sell carberoutor jets....does anyone know what size this carberutor takes or should I try and go up a few sizes and see if that helps ?

I havent run a full tank of gas thru this engine yet..and sure would like to get this fixed if possible, before going to my 2nd tank of gas for break in procedure

 

[misteright1_99]

I dont think your going to find jets for these carbs, but I believe stock is .026 or #71 drill bit size.

 

[rumme]

Hmmm...I wonder if other people are having the same problem as I am...and cant figure out whats wrong, and are just running their engines with the choke lever about half way up ?


I guess I could try and drill out the main jet a slight bit bigger, whcih should mean more fuel getting thru the carb..correct ? That might be my only option left since I have the needle clip all the way in the bottom position and it still isnt get enough gas. If I accidnetly drill the jet a little to big, I could always raise the needle clip and lower the needle valve down again to compensate...right ?

 

[rumme]

im only about half way thru my 1st tank of gas. Im assuming once the engine is broken in, I would notice a significant increase power/ top speed ? I weigh 235 lbs and it seems like the most this engine is doing is about 15 mph when I give full throttle and then back off . { I dont break in my engines with just giving 1/4 throttle for the intital break in period, I beelive its best to hit all throttle positions and not stay there for more then a few seconds at a time } ..

How many tanks of gas does one usually have to go thru with these engines, before a notciebale increase in speed/power is realzied ?