Why Don't I have Uniform Speed?

inspectorcritic

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I take the same stretch of road one day at 24 MPH next day I bearly manage 16 MPH also is a hazard on turning to cross the street I should have this speed to cross the distance of uncoming car but oops bog out.
 

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Steve Best

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Hard to guess every possible factor, but I'd guess your jetting to be the most likely candidate for inconsistent top speeds, especially where you mention "bogs out".
 

Wags

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I would also guess its jetting. Temperature and humidity change from day-to-day so one day it's running great the next day it will run sloppy. Especially if you're jetting is right on the threshold. Cold mornings vs. Warm mornings kind of thing. What carburetor are you using?
 

DuctTapedGoat

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if you want consistency maintenance of the top end of the engine and the clutch helps a lot, is what I've found.

Repaired heads from warping and new head/exhaust gaskets is a high priority maintenance on any kit, its the #1 offender that I see... and then clutch maintenance keeps that compression tightly driving your bike.

16mph I would be questioning the left and right engine seals in addition to the head and exhaust even effective ground.

Carburetor tuning can have a drastic effect as well if it is miscalibrated.

Also bicycle maintenance is important.

Brakes bearings and welds oh my it is still a bicycle.

references:
I have uniform speed at 32-37.5 mph on 24" wheels
 
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inspectorcritic

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How does one tell when heads warp? I mix match engines was running OK but I'm losing power now.
I have a CNC carb some MP pulled me over I told him my sad story he said it's your carb from using ethanol here between hot and cold seperates leaves gunk in the bowl drain it check needles, so I did ran better for while but problem keeps coming back.
 

CrazyDan

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Clean out carb again and empty your tank then clean that plus fuel lines. Put in all new fuel.
 

DuctTapedGoat

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How does one tell when heads warp? I mix match engines was running OK but I'm losing power now.
I have a CNC carb some MP pulled me over I told him my sad story he said it's your carb from using ethanol here between hot and cold seperates leaves gunk in the bowl drain it check needles, so I did ran better for while but problem keeps coming back.
Just take a look. It arcs like a bridge and the squish becomes nonexistant in the front and back. Look at the squish pattern on a new head gasket, warped head causes air leak at the front and back of the head. To repair just sand the mating surface of the head by hand, I use 80 200 2000 and it lasts a while. you'll know its done when you can see the sanding strokes are creating a flatter surface area.

I have 2 heads, one on my bike and one being sanded.
 

Street Ryderz

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Just take a look. It arcs like a bridge and the squish becomes nonexistant in the front and back. Look at the squish pattern on a new head gasket, warped head causes air leak at the front and back of the head. To repair just sand the mating surface of the head by hand, I use 80 200 2000 and it lasts a while. you'll know its done when you can see the sanding strokes are creating a flatter surface area.

I have 2 heads, one on my bike and one being sanded.
There is no such thing as a squish pattern on a head gasket!Why are you telling people things to check and do when you dont have a clue what your talking about!If your going to use the terminology at least learn what it means so you can use it accordingly!
 

DuctTapedGoat

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I'd guess he means the bite mark from the compression ring of the head.
If that makes more sense - but surrounding the bitemark is where squish occurs. If there is no full concentric bitemark then obviously its a warp sign, a great test is with a fresh new gasket. Look at some old gaskets, there is the crimp, the squish and between the crimp and the squish, which shows where it is not level. My head is warped like a record every few hundred miles, that's not break-in that's broken.

Its a standard factor that gaskets squish to create seal and there is a pattern that reads signs; especially warping.

There is many patterns, like spark plugs can only handle X amount of squishes before there is no squish and seal left and the same is true for any gasket whether there is a bitemark or not.

It is the same concept as a plug chop, no matter how many miles on it there is a few patterns of reliable information in there.

All you are doing is investigating a plane less than <1mm high for any changes - gasket crimping, squish or lack of squish, wetness/dryness, carbon buildup, warping, burn damage

In a perfect world every time you crack the seal or even relieve pressure on the seal replace the gasket. My base gasket is over 1000 miles, and its starting to soften from being squished so many times and exposure to gas/oil.
 
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