Still Having Problems

MrLarkins

HS Math Teacher
Jun 17, 2008
487
0
0
45
Arkansas
This is frustrating...I still can't get my bike over 20 mph. I use to get 30+ easily. Now it bogs do when i get to 20mph. I have lots of throttle left, but it only starts to chug when I use the rest of the throttle. My mixture is right, my clip is on the highest point...could the fact that I ported my exhaust have caused this somehow...maybe causing a backflow air problem?

I'm grasping for straws here.:(
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
0
0
45
Arkansas
the plug is black and sooty...and I am sure that my ratio is 44:1 ! It shouldn't be black and sooty with that ratio...the thing is, the first quart turn of the throttle the engine runs perfect. but after that the rest of the 3/4 turn of the throttle the engine bogs down, chugs, and won't rev past that rpm...that would probably explain the black and sooty plug...its getting more gas but is not burning it...right? so why not? why is there a barrier? should i video it or something?
 

Ghost0

New Member
Mar 7, 2008
764
0
0
Bellingham, WA
It sounds as though you are running into a rich condition at full throttle. You may need to go to a smaller jet. You can buy a new one or do the solder and drill trick. I found that after modifying my intake and exhaust ports that it ran richer and I needed to make the jet smaller. Here is the drill kit that I bought.
25pc. Carburetor Drill Kit I also attached a drill chart for reference.
In my opinion these carbs are jetted to deal with all of the issues the engine has, intake leak and poor fit of intake and exhaust manifold. By the time you fix these things the carb is no longer jetted correctly. You can double check that the rich condition is your issue by running the bike at full throttle and slowly applying a little choke. If it runs better with a little choke you would need a larger jet, if it runs worse you will need a smaller jet.
 

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Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,664
5
38
Duvall, WA PNW
www.sickbikeparts.com
Agree with the overly rich condition. Just dropping down to a .65mm jet without even selectively trying other sizes nearly eliminated any high RPM rich 2-stroke symptoms, but hold the phone because I'm still tuning.
 

Ranger

New Member
Aug 7, 2008
55
0
0
27
Have you tried a thinner air filter? Or just simply taking off what ever you did to the exhaust?

A smaller, less dense air filter and a bigger exhaust pipe should help.
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
0
0
45
Arkansas
i guess ill try to 're-jet' it

what is the process? do i need a new needle? or do i just fill and redrill the whole and keep the same needle? if i need a new needle, where do i buy it?
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
38
68
pampa texas
you don't need to mess with the needle sounds like your main jet's hole is too large. try to find out what size it is by using a set of micro or carb jet drills so you will know the jets size that it is now.
then solder it shut. I solder them shut and redrill them to either 0.025 or 0.026 thousands.
If you don't mind a wait I can do your jet just let me know all I will need is the main jet. look at my carb post and you will be able to see just what I'm talking about.
Norman
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
38
68
pampa texas
It gives a little smoother ride, can make the tire run hotter and may cause a flat, makes you or the engine work harder to get up to speed (robs power as the engine has to work a lot harder)
I inflate mine to the max pressure all my tires front and rear are at 60 psi.
I made you some gaskets do you want them?
 
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MrLarkins

HS Math Teacher
Jun 17, 2008
487
0
0
45
Arkansas
:rolleyes:
well I aired it full last night and by morning it was completely flat! so I guess I got to take the rear tube out (not going to be fun) and patch it. I wonder what I ran over?

oh well.:ride:
 

Biker Mike

New Member
Mar 21, 2008
143
0
0
Cropwell Alabama
Ok, check this out...I had a sputter and power problem with one of my kits as well. It ran great for the first week and then all of a sudden no power, sputter, 20mph top end etc.... I finally figured it out after 2 carb's, new wire and end, new plug, new CDI, new rings and all. Here is what caused my problem and once done I am riding SMOOTH once again.

The problem was restricted Air/Fuel flow to the cylinder by the factory intake gasket. It seems the gasket is cut to the size of the intake and not the cylinder. Once the gasket was saturated with fuel and oil it expanded and interfered with the flow.

The fix: Remove the carb and intake. Cut the intake gasket center hole out using the engine side as a guide (I used an exacto knife). Be careful not to get pieces in the engine. Add blue sealer (small amount) to both sides of gasket and re-install. Mine runs GREAT now.

I hope this helps. Let me know if anyone needs further info on this such as symptoms,or fix procedures. I love it when a plan comes together!
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