Help! Supercharger related issue...

[Harley8029]

Has anyone had this issue before? I recently replaced my supercharger belt recently. Its a regular M112 no ported blower. Motor and SC are in great shape with no issues, spins freely in regards to bearings etc form snout. Bottom line is that the motor jerks when I tried to go over 2k rpm. I cannot WOT. When I take the belt from SC off I have no jerks or issues on passing farm road lanes. All hoses are well tacked together. Don't know if its a air leak related or spark plugs maybe? But again sparkplugs are in great shape and not knocking sounds. It just jerks or stuters when trying to WOT. Thanks again to everyone!

So far I changed a coupler that had slit that attaches to the back left side of the plenum, which connect to the pcv valve hose. Hasnt resolved the issue.

 

[Harley8029]

Well no luck yet. This jerking motion happens when the 3rd and 4th gear kick in "Low End Torque" is when it feels that loss of pressure. No "check engine" yet. I'm "SOL" still since here in south Texas there are no tuners that specialize with SC's only turbo shops. And my closest place to take a look at would be Lethal Performance in San Antonio, TX.

What does the cable thats underneath the throttle cable that goes to a box behind the air filter do? Thanks for the help!

 

[4rd Toys]

I believe you are referring to the cruise-control cable & assembly....

 

[Harley8029]

Got that. Thanks

 

[Harley8029]

My valve actuator looks to be working properly. How do you disgnose that part if it has gone bad?

 

[4rd Toys]

Did you resolve your issue?


Since no one else has chimed in:

If your SC pulleys, top to bottom, are all stock- did you check the length of the new serpentine SC belt with your "old" one?

Did you verify the condition of your SC tensioner?

That's where I would start..... Maybe someone else can confirm or dispute this. But the SC serpentine belts on the L & HD are different part numbers. I would research the part# to confirm what you have in-hand. [L- lightning HD- Harley Davidson]
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Maybe change the PCV & hose with new parts that attach to the plenum you are talking about too... something there might be wrong causing the problem... Maybe pull hose off & cap it temporarily... see if you motor runs differently...
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Hopefully this helps- if not I would take apart/disassemble the Air-intake assembly including the plenum to see if there is any obstruction....

 

[04MystiCobra]

Water in spark plug bore or bad coil(s)? After washing the engine I get that from time to time if I'm not careful.