Jetting messed after porting?

[Shift-MX]

My cylinder has recently been port/milled etc by mr.gorr and I have been having jetting problems ever since. Which most of you already know (And hate me for that one flame). I took my bike into the shop...again today. The first time the power valves were sticking and not opening properly. Well thats been fixed. After riding it for a while since then it now wont idle...at all. Ill come to a stop and it'll just quit. And it bogs down low, and iv gone from a 48 pilot all the way to a 55, and it idles now. But its very "eratic", itll idle at low RPM then JUMP up high for a few seconds...then idle down and may stall. They did a leak down test and everything checked out there. The float height is where its supposed to be at. Any suggestions? Im outta ideas...thxs for any info.

 

[r_rider28]

If it bogged and would not idle with the 48 and got a little better with the 55 but surges then you are still too lean. Also check your air screw. If it is turned over 2 1/2 turns out you can turn it in as far as 1 1/2 to 1 1/4 turns out and this will richen the low end circuit a little as well. Try going richer on the pilot and check the air screw. Sounds like you are going the right direction but you need to go a little more. If this doesn't help keep us posted for more ideas.

 

[Shift-MX]

Tried the air screw, but havent gone ritcher. In the manual the stock is a 55...i never thought you would have to go ritcher though?

 

[KX125pinball]

You will have to go richer than stock. It's not uncommon for you to have to. Ussually when the engine is ported you will want a bigger pilot jet.

 

[Shift-MX]

But it smokes...alot. And spooges outta the silencer?

 

[Rich Rohrich]

Originally posted by KX125pinball
Ussually when the engine is ported you will want a bigger pilot jet.

Based on what exactly??????

 

[r_rider28]

have you changed the needle setting and main jet since the motor work? If you have what jet and needle setting were you at before and where are you at now? I'm thinking you may have your circuits at the opposite ends of the spectrum, way too lean on one end and too rich on the other. Give us those before and after specs and we will give our best suggestions based on the information you give us.

 

[bigred455]

check the front of the carb to air boot connection,and manifold area,I know they did a leak down test ,but at least check these areas.Usually an air leak if anything will not stall the idle.It will run erratic like you described,also take out the slow jet and clean out the passage of the carb.Usually if you are too rich on the pilot and after you chop the throttle the idle will drop all the way down and either stall or come back up a little. How old is your fuel?check your vent hose on the gas cap,make sure it isn't pinched.If everything checks out keep going up on the pilot.

 

[Shift-MX]

Alright, thxs for all the info guys it was pretty helpful. I ended up being WAY to lean on the pilot. And i couldnt figure it ous so i brought it to the shop. I had to go WAY ritcher on the pilot and the needle clip is at its top postion now. It smokes...ALOT but doesnt sputter. Anyone got any ideas how to cut down on the smoke? I guess with the porting it just needs ALOT of fuel.

 

[r_rider28]

As I suspected, way too lean on the pilot and too rich on the needle and main. Try going to a leaner needle and leaner main jet. This should clean it up.

 

[Shift-MX]

actually i went eitcher on the main...ritcher on the pilot...needle is at stock postion. So i more less had to go ritcher all over.

 

[Rich Rohrich]

It sounds like you have an air leak, it's rare to have to go richer all the way across the board on this engine if it was jetted correctly before the porting.

 

[Shift-MX]

But like i said...they did a leak down test. And never found a leak. Any suggestions?

 

[Rich Rohrich]

Take it to someone who knows what they are doing.

 

[Shift-MX]

They know what there doing.

 

[Rich Rohrich]

Originally posted by Shift-MX
They know what there doing.

If you say so. :thumb:

 

[r_rider28]

Hold up. You went richer across the board for what reason? I thought your problem was at idle? If going richer on just the pilot did not correct the problem and you had to go richer everywhere to correct it, and it now smokes then you are either 1, too rich, or 2, you have a air leak. If you lean the main and the needle out and the smoke goes away but you still have the same symptoms of surging rpm's then you definately have a air leak. More than likely the air leak is where the carb mounts to the intake boot or where the reed cage bolts to the intake on the engine. I have never done or seen a leak down test but I assume they do this with the carb and reed cage off. If I am right then a air leak could exist in that area. If not then maybe you should consider having someone else do a leak down test to insure the results are accurate.

 

[Shift-MX]

they take the carb out...leave the reeds in. And it doesnt smoke that much anymore. And its running...better.