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    • 1982 CX500 Turbo / 1983 CX650 Turbo.

Two very unique variants of the CX/GL engine line.

The 1982 CX500 Turbo, in its day, was an engineering marvel: at the time, arguably the most advanced motorcycle ever built. It was fuel injected, turbocharged, and had an onboard diagnostic computer (ECU). Front Forks included Honda's TRAC anti-dive technology with air assist. Rear suspension was a Pro-link monoshock with air assist. Rounding out the package was dual disc, dual pot caliper brakes in the front, and single disc, dual pot caliper in the rear. Honda claimed 82 horsepower. While it was a highly acclaimed motorcycle, it had some very distinct issues. Due to the high weight of the bike (576 lbs) and severe turbo lag, the low compression engine chugged off of the line until the turbocharger's boost finally kicked in around 6000 rpm. Once the 19 lbs of boost kicked in, the bike became a rocket. It had been compared to a 400cc bike off the line, and a literbike on boost. This unique engine characteristic made the bike a challenge to ride for those who had never experienced instant onset power. If boost unexpectedly kicked in when the rider was in a deep lean, the pre-silica technology tires of the day often did not have the grip to keep the rear tire from spinning up. Even modern technology tires can slip under the extreme onset of boost. As advanced as the bike was, it fell short of the expectation of a small engine with literbike power.

In 1983, the introduction of the CX650 Turbo had solved the turbo lag issue, and gave Honda the small engine/literbike power it had sought after with the 500T. The overly complicated 500 Turbo sensor and ECU system had been simplified, compression had been increased, boost had been decreased to 16 lbs, and a very well rounded engine powerband was created.

Unfortunately, the high cost of adding the systems needed for turbocharging, the added weight, the improvement of metallurgy allowing for higher compression engines, and the insurance industry's extreme prejudice against anything turbo or supercharged, killed the production of turbocharged motorcycles, and Honda dropped the line by 1984.

Known Issues aka "THE TRIPLE BYPASS":

See: Triple or Quadruple Bypass

    • Stator- This is an engine out repair.

Both bikes suffer from regular failure of the Stator, with 20,000 miles historically being end of the stators life. Part of this is simply the fact that Honda decided to bathe the stator in oil. Over time, this bath cooks and breaks down the stator wire resin and shielding.

    • Stator to Rectifier Connector

Another of the reasons for early stator death seems to be the stator to rectifier connector. These connectors have been known to melt after a few thousand miles. Once the connector melts, and the wires short/ground to each other, the stator is done for. To eliminate this problem, some owners have begun to take the connector out of the equation and solder the stator wires directly to the rectifier wires, then seal them with heat shrink wrap.

    • Cam Chain and Tensioner system- This is an engine out repair.

These are good for about 40,000 miles, but should be regularly checked after 30,000.

    • Mechanical Seal

Replace when leaking. When the Mechanical Seal fails, there will be a small puddle of coolant "weeping" from a small hole. You will know it when you see it. Fortunately, with the turbo models, this can be replaced without removing the engine, however it might as well be replaced while the engine is out.

CX650 Turbo "Quadruple Bypass"

See: Triple or Quadruple Bypass

    • Starter Clutch Torx Bolts- This is an engine out repair.

In addition to the Triple Bypass on CX500 models, the Starter Clutch Torx Bolts MUST be replaced on the CX650's. No one is sure exactly why these fail so often on all CX650 models, but the general consensus is that the heavier engine components seem to put more strain on the starter. All CX650 Engines (turbo and naturally aspirated) are prone to "kick back" on the starter clutch, and the Torx Bolts tend to back out or even sheer.

      • Note: Once Torx Bolts have been removed, they cannot be reused.
    • Issues stemming from aging components.
    • As these bikes reach the 30 year mark, some new issues are coming to the forefront.

"P" Sensors.

    • The sensors that make the fuel injection and turbocharging system work, the P1, P2, PB, and PIGN sensors, seem to be nearing the end of their serviceable life.
    • There are presently more reports of these components beginning to go out of specification and/or fail.
    • Unfortunately, there are no known replacements, modern or old, aside from the limited supply of used sensors from bikes that have been stripped.
    • UPDATE
    • As of March 2013, The Pb and P1 Sensors can be replaced with a modern unit.

Suzuki MAP-sensor or Toyota MAP sensors:

Below the details of the Suzuki-sensor. Brand: Denso. Type number: 100798-5630. Suzuki orderingnumber: 15620-35F00. Suzuki description: Sensor Boost, IAP (Inlet Air Pressure) sensor. Requires Connector type: DJ7036F-2.2-11/21 The mentioned sensor-type is fitted on the following Suzuki motorcycles: Type Year of production. 2003 - 2006, AN 650 2001 – 2004, GSXR 1000 2000 – 2003, GSXR 750 2001 – 2004, GSXR 600 2003 - 2007, SV 1000

Below the details of the two Toyota sensors. Brand: Denso Type number: 100798-4530 and 100798-5256 Toyota ordering number: 89420-16080 and 89420-02010 Toyota Starlet ‘96 – ‘99 and Corolla ‘95 – ‘04.

    • A HUGE thanks to Leo Knijnenburg and Ko Maljaars for testing and confirming these sensors, and sharing this information with the CX Turbo community.

Brake systems. Back in the day, these were fairly solid brakes; after 30 years, we are beginning to see more owners converting to stainless steel brake lines to replace aging rubber.

  • A highly recommended steel braided brake line vendor is coastguard1975 on e-bay. His brake lines come in stock 3 piece front (unlike Galfer or EBC), and 1 piece rear, and lines are thicker than most other aftermarket steel braided lines, so the appearance is closer to stock, although they are still not as thick as rubber lines. In addition to black, many other line colors are available, and he can make custom sizes for any application.

A few owners are going all out, rebuilding and cleaning the entire system, then trying the new DOT 5 silicone fluid. Results are still pending, and this method is not recommended for these bikes at this time.

Here is a document the dealer got for setting up the bike from the factory. Link to forum thread:

AFTERMARKET PARTS Windshields/Windscreens Skidmarx UK Limited. Unit 16 - 18 Cambridge Road, Weymouth, Dorset DT4 9TJ , UK Phone number (0044) (0) 1305780808 . The standard height and flip top high screens were the same price at about £40 GBP each + P&P (that's British for Shipping and Handling)

Gustafssen Plastics in the U.S. makes Stock height through 10" over windshields (not recurved) Prices range from $135-$160 plus shipping. You have to drill your own holes (with a special drill bit), and be very good at making hole templates. They shatter easily if you screw up. Gustafsson Plastics, Inc. 1704 Lakeside Ave #1, St. Augustine, FL 32084-3567 / Toll Free 1-888-824-3443

Replacement Air Cleaner Elements. The Moto Air part number is 2054. Moto Air Holland, Poppenbouwing 15, 4191 NZ Geldermalsen, The Netherlands. Website (, e-mail ([email protected]). The Air Cleaner material is resistant to the oil as given in the Honda Workshop Manual (gear oil, SAE 80 - 90). In addition; Moto Air also supplies suitable oil for oiling / re-oiling the Air Cleaner Element.

Turbocharger Oil Feed Repair. Tip to O-ring groove - 2 mm O-ring groove width - 3 mm O-ring groove to turbo center-housing flange - 4 mm Overall from tip to turbo housing flange - 9 mm.

Oil hole diameter at tip - 2 mm O-ring inside diameter - 7 mm O-ring outside diameter - 11 mm.

Lathe and Drill from Billet Aluminum.

Drill out mating surface in the oil inlet.

Press fit with a locking sealant (not too much, you don't want to get any on the feed hole).

<more to follow at a later date>

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