Evo trouble
Seasoned HDF Member
Joined: Feb 2007
Posts: 6,086
Likes: 1,128
From:
I will guess that you mean gaskets with an S since there are two.
If gaskets are original factory gaskets then it is kinda hard to see unless it was changed lately. Some people test by spraying a small amount of WD40 into the area while holding a steady idle.
I will also guess that you reviewed the Y pipe really well since the crack is sometimes hard to see since it is located under the right passenger floor board.
Is exhaust all original? with no leaks at head or clamps?
If gaskets are original factory gaskets then it is kinda hard to see unless it was changed lately. Some people test by spraying a small amount of WD40 into the area while holding a steady idle.
I will also guess that you reviewed the Y pipe really well since the crack is sometimes hard to see since it is located under the right passenger floor board.
Is exhaust all original? with no leaks at head or clamps?
Thread Starter
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Stage III
Joined: Jan 2024
Posts: 3
Likes: 0
From: Arkansas
I will guess that you mean gaskets with an S since there are two.
If gaskets are original factory gaskets then it is kinda hard to see unless it was changed lately. Some people test by spraying a small amount of WD40 into the area while holding a steady idle.
I will also guess that you reviewed the Y pipe really well since the crack is sometimes hard to see since it is located under the right passenger floor board.
Is exhaust all original? with no leaks at head or clamps?
If gaskets are original factory gaskets then it is kinda hard to see unless it was changed lately. Some people test by spraying a small amount of WD40 into the area while holding a steady idle.
I will also guess that you reviewed the Y pipe really well since the crack is sometimes hard to see since it is located under the right passenger floor board.
Is exhaust all original? with no leaks at head or clamps?
Stellar HDF Member
Joined: Feb 2013
Posts: 3,072
Likes: 1,727
From: Dallas, Texas
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Grand HDF Member
Joined: Apr 2007
Posts: 3,727
Likes: 3,072
From: Brighton, MI
What do your spark plugs look like? Rich or lean?
If lean suspect intake manifold seals or faulty petcock. Check the vacuum line going from carb to petcock or VOES.
As Dan89FLSTC mentions, any missing? Is the "popping" more like a cough? There is a thing called a lean cough with these evo's from bad intake seals or leaks, then there is a cylinder firing "miss" that can be from a bad ignition cam sensor.
With cam sensor, the problem usually crops up after the bike has ran for awhile say 15-30 minutes then starts acting up.
When you say "jets are clean" which jets are you specifically talking about? How about the emulsion tube? idle transfer ports?
If lean suspect intake manifold seals or faulty petcock. Check the vacuum line going from carb to petcock or VOES.
As Dan89FLSTC mentions, any missing? Is the "popping" more like a cough? There is a thing called a lean cough with these evo's from bad intake seals or leaks, then there is a cylinder firing "miss" that can be from a bad ignition cam sensor.
With cam sensor, the problem usually crops up after the bike has ran for awhile say 15-30 minutes then starts acting up.
When you say "jets are clean" which jets are you specifically talking about? How about the emulsion tube? idle transfer ports?
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Seasoned HDF Member
Joined: Aug 2008
Posts: 5,071
Likes: 1,006
a carb is a dirty port devise, meaning, there are air jets and passages to boot. these control mixture.
a lot of people will think right off it is a lean pop, but it actually could be from a rich mixture.
i assume it is the exhaust and not back feed through the cab.
right off, i would check float level. when accelerating, the mix will go rich and excess fuel will collect in the exhaust and when conditions are right it will ignite, the same for decel, fuel build up in the exhaust.
the plugs may/may not show, depends upon many things.
inline spark testers will show if the ignition is dropping.
a lot of people will think right off it is a lean pop, but it actually could be from a rich mixture.
i assume it is the exhaust and not back feed through the cab.
right off, i would check float level. when accelerating, the mix will go rich and excess fuel will collect in the exhaust and when conditions are right it will ignite, the same for decel, fuel build up in the exhaust.
the plugs may/may not show, depends upon many things.
inline spark testers will show if the ignition is dropping.
Grand HDF Member
Joined: May 2008
Posts: 4,329
Likes: 3,626
From: Picayune, Ms.
Vacuum leak in VOE's either at the switch or the carb. Maybe the hose has a leak. On some bikes the hose from the carb to the switch is inside a protective sleeve. Make sure you check the hose and not the sleeve.
