Widowmaker 4-into-4 Megaphone Exhaust System for Honda GL1000

This custom exhaust system is currently out of production. Contact – Hank Thibodeau for more details.

For my exclusive Master Carb Overhaul Kits and other items…click here


Honda GL1000 4-into-4 Megaphone Exhaust System by Widowmaker

  • Custom fabricated by my friend and fabricator extraordinaire – Hank Thibodeau.
  • Removable baffles.
  • Complete with proprietary headers constructed with heavy gauge tubing and laser cut flanges.
  • Sidestand and centerstand use is retained.
  • Unlike the OEM system, each side can be removed independently.
  • Headers are ceramic coated (inside and out) for long life and beneficial scavenging effect.
  • Individual, high quality, detachable mufflers.
  • Mufflers are made of heavy 16 gauge material.
  • Mounting hardware and instructions included.
  • Exhaust header to cylinder head crush gaskets included.


  • The system is quite loud! Sounds like a cross between a small block Chevy and a very angry Porsche!
  • The prototype shown is mounted onto a bike that has frame modifications which influenced the design of the rear support bracket on that unique bike. Production models have a different rear support system. No frame modifications are required.
  • Centerstand will “ride” approximately 1″ lower than normal. You may wish to remove the centerstand for best appearance and maximum cornering clearance.
  • Designed for Honda GL1000 only (all years). Will not fit Honda GL1100 models.

Important Order Details:

  • This is a limited production Widowmaker product.
  • Contact Widowmaker directly for current pricing and availability
  • Allow 6-8 weeks for delivery.
  • Each system is custom made for each customer.
  • Each system is test fit onto an actual GL1000 during construction to insure proper fit.

To order, contact:

Widowmaker Custom Design and Repair

5582 Mt Harmony Church Rd.

Rougemont, NC 27572

(919) 618 – 7202 or

(336) 364 – 8535

website: Widowmaker Custom Design and Repair

email: nitetrain74@earthlink.net

4 Into 4 Megaphone Exhausts

Honda GL1000 4-into-4 Megaphone Exhaust System by Widowmaker


  1. clive oakes says:

    Hi can you tell me if the con rod bolts on a 1976 GL 1000 engine can be used a second time ?

  2. Jeremy Cote says:

    With the installation of this exhaust is carb rejetting required?

    • Jeremy.

      Not re-jetting would be required so long as you use the OEM air filter.

      Honda constant velocity carb’s of this vintage and design are very sensitive to flow dynamics on the intake side.

      That’s why departures from the OEM air filter are not advised. K&N makes a good product, but I don’t recommend such air filters for these bikes. The Honda engineers have already calibrated the carbs for the optimal air flow to result in max power and efficiency. CV carbs are theoretically “self-adjusting,” but the reality is that they are rather sensitive and their inherent flexibility is easily exceeded.

      Ditto for “pod” filters of any brand.

      Adding even more air via a “free-flow” filter does always not help performance. In fact, it can introduce chronic, undesirable leanness which is hard to overcome on carbs that were not designed to be “tuned” to any great extent.

      Aftermarket filters typically make lots of “noise,” but noise does not equal power.

      Finally, these carbs are not particularly “tunable.” The jet and needle choices are very limited.

      I’m not alone on this point of view. Per my friend and carb guru Mike Nixon:

      “One thing folks seem to not be willing to believe is that changes to the intake side of the engine have 20 times or more the effect that changes to the exhaust side have. Specifically, change the exhaust, no change to carburetion. Change the air filter type however, especially going to pods, and a HUGE change requiring changes to the main jet of over 10 jet sizes! This is likely your problem if you are using pods and the carbs have not be rejetted to them. Fitting the stock airbox and air filter is of course the better solution. 🙂 Mainly because, although the carbs CAN be jetted to match the pods, and the engine will run right, the factory seamless throttle action will suffer, even with the proper jets.”

      Setting aside the dubious merit of more exhaust noise level, these bikes will tolerate almost any exhaust without the need to re-jet so long as the intake is the stock setup.

      Keep in mind that the OEM exhausts on Hondas of this vintage are not only quiet, they flow exceptionally well and out-perform virtually all aftermarket pipes.

      Again, noise does not equal power.

  3. Robert McNeil says:

    I have a 1976 Honda GL 1000 and I was wondering what a 4-into-4 exhaust coast my bike already has a lot of custom parts and paint just want to switch out the exhaust ?


  1. […] exhaust like this: https://www.randakksblog.com/widowmaker-4-into-4-megaphone-exhaust-system-for-honda-gl1000/ (Now out of […]

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