Hard Starting Harley Milwaukee-Eight? Two Very Easy Fix From Sumax.

If it seems like you need an extra punch of power to ignite your Milwaukee-Eight motor, Sumax offers a 1-2 punch for a fast, easy and cheap fix. Your conventional spark plug wires fire intermittently no matter what coil or ignition you have. That is why you see carbon build up on your spark plugs. Sumax’s Thundervoltv50 wires fire a solid steady stream to unload your spark plugs. It is like running new spark plugs all the time. Colors available: black, red, blue, purple, orange & yellow.

Next add a set of their 2 Ga. Extreme Duty Battery Cables where over 2000 strands of copper transfer the amps to crank your motor to life. These flexible cables feature a thermo plastic rubber jacket with heat shrink sealed with glue at either end. Both plug wires and battery cables are custom fit ready to plug in or bolt on. Spark Plug Wires and battery Cables are each $78.00/set or $156.00 for the package. Call Sumax 315-768-1058  to receive free priority mail shipping on package.

19 Responses to “Hard Starting Harley Milwaukee-Eight? Two Very Easy Fix From Sumax.”


  1. 1 richards May 10th, 2017 at 10:58 am

    It says above….”If it seems like you need an extra punch of power to ignite your Milwaukee-Eight motor, Sumax offers a 1-2 punch for a fast, easy and cheap fix. Your conventional spark plug wires fire intermittently no matter what coil or ignition you have. That is why you see carbon build up on your spark plugs. Sumax’s Thundervoltv50 wires fire a solid steady stream to unload your spark plugs”.

    The spark plugs fire, on time, slightly ahead of TDC, near the end of the compression stroke to ignite the gas/air mixture. They need not fire at any other time during the 4 stroke process. Carbon build up is the result of too rich a mixture, or oil consumption. I’m not sure what ” Sumax’s Thundervoltv50 wires fire a solid steady stream to unload your spark plugs” means???

  2. 2 huls May 10th, 2017 at 11:59 am

    Nice piece of sales gibberish. Is there any real information on these items besides the colors?

  3. 3 rebel May 10th, 2017 at 1:23 pm

    mines been hard starting for years

  4. 4 BobS May 10th, 2017 at 4:55 pm

    Richards I would add that running an Octane higher than necessary results in incomplete burn and hence carbon deposits too.

  5. 5 James just another crazy kiwi May 10th, 2017 at 7:57 pm

    Hi BobS,
    I know very little about fuel. I run 98 when I can, is that ok for a twinky and Evo ?

  6. 6 Mike May 10th, 2017 at 10:47 pm

    Let me see if I have this right. . . $20,000 motorcycle that needs $156.00 aftermarket wires to get it to start properly..

  7. 7 dhaffa May 11th, 2017 at 5:34 am

    [quote] … are each $78.00/set or $156.00 for the package [quote]

    Wow, Sumax really helps and saves me a x2-multiplication with there package price … or where is the benefit?

    and as addition to Mike … a €31,300 motorcycle (the cheepest M8 here) needs aftermarket wires?

  8. 8 BobS May 11th, 2017 at 6:29 am

    Crazy Kiwi, I believe your 98 is the equivalent to our 91. NZ-Aus use a different measurement than Trumpistan so you may need to google the conversion. I believe in your case 98 is fine. Over here we have a LOT of guys that falsely believe higher octane = more power, better burning, so they go find themselves a station with 94 or higher, 114 or higher there. And they put that in a motor with 9.4-1 compression. The result is carbon buildup on the valves and piston crowns which creates hot spots in the combustion chambers. They create the mess they think they’re preventing with higher than needed Octane.

  9. 9 DFW May 11th, 2017 at 7:10 am

    Mike said: “Let me see if I have this right. . . $20,000 motorcycle that needs $156.00 aftermarket wires to get it to start properly”. Mike, you might want to do an on-line search of Milwaukee Eight problems. Apparently, oil pumps are failing already…after 110 miles low oil light comes on. Some need total engine replacement. Welcome to the world of Harley.

  10. 10 rags May 11th, 2017 at 7:26 am

    more sales bs for yuppies

  11. 11 Doc Robinson May 11th, 2017 at 8:52 am

    Hard starting M8? Rubbish! I’ve just spent four months on a Twin Cooled M8 Ultra and six weeks on an M8 Road King doing lots of miles on both. And buddies of mine with M8s have not experienced this at all. Marketing gibberish is what Sumax are spouting.

  12. 12 chris May 11th, 2017 at 9:26 am

    Ill take the Brooklyn bridge as well thanks.

  13. 13 kirk May 11th, 2017 at 9:32 am

    We have had several customers come to us with starting problems. In the past those with big inch high compression motors were sold high torque starters. We found that a better spark transfer eliminated the problem. You did not need to spend big $$ on a new starter.

    Those customers with hard starting Milwaukee 8 motors stated that their bikes turned over easier with the 2 ga battery cables. Dyno tests in the past show a marked improvement in HP & Torque when adding the Thundervolt plug wires.

    Cost for a 4 wires set of plug wires is $78.00. Cost of Battery cables is $78.00. Add those two together and it is far less than a new High Torque Starter.

    Hey… if your bike starts easy, quit whining and be happy!

  14. 14 James just another crazy kiwi May 11th, 2017 at 1:30 pm

    Thanks BobS ,
    I will look into that. 98 is only available through one company here.The rest is 95 and 91.
    I will do some reasearch. I have other motors that pink with out the higher octane gas. Fuel here has been a bit of a joke in the past.

  15. 15 Easygear May 11th, 2017 at 1:45 pm

    Evo forever
    forever Evo

  16. 16 Carl H Hursky May 11th, 2017 at 2:26 pm

    Was there EVER a Harley made the aftermarket companies did not offer just about everything on the bike to improve it? I got tired of buying a bike and spending $27,000 Then spending thousands to fix it. Glad I dumped HD and ride an Indian.

  17. 17 Roberto May 11th, 2017 at 5:10 pm

    I use those battery cables on 2012 Road King with a lithium battery and a Starterdrives starter clutch. Works great!

  18. 18 Pat h May 11th, 2017 at 8:56 pm

    The aftermarket offers parts to improve a motorcycle some is snake oil some is legit no manufacturer makes anything that can’t be improved on in the case of Indian (it runs with its own problems) it’s butt ugly and won’t be around long hence not much aftermarket, had 3 bikes I put over 100k on each never did more than tires batteries and brakes all made in milwaukee come to think of it I still own them and a bunch others 27k would sure maintain a lot of bikes

  19. 19 Gasbag May 15th, 2017 at 8:45 am

    Good grief.

Comments are currently closed.
Cyril Huze