Recommended Honda GL1000 Timing Belt Change Interval

My recommendation for Honda GL1000 timing belts is simple: It you can’t verify their age – change them! Thereafter, my recommendation is to change them every 5 years or 25,000 miles…whichever comes sooner. Obviously, they should be inspected from time to time for any evidence of damage, oil contamination or deterioration which would warrant immediate replacement.timing belt replacement

If you saw GWRRA’s Wing World magazine’s June, 2006 issue you might have seen a letter to the Workbench column about GL1000 timing belts. The writer kindly referenced me as a “well-known wizard on the GL1000” and mentioned my timing belt change interval recommendation. I doubt that I’m worthy of the credential bestowed upon me by the writer of that letter!

In any case Stu Oltman, GWRRA’s Senior Technical Editor, took exception with my timing belt change interval advice. Stu is a very knowledgeable fellow and I have great respect for his expertise. He correctly points out that oil contamination and incorrect installation can shorten cam belt life considerably. In the separate article (same issue) on the ’75 restoration that he did for the GWRRA corporate office, he admits (page 43) that he doesn’t have much experience with the Gen I bikes. So, when he characterizes my 5 year / 25,000 miles service interval as “severe overkill,” I find that very interesting information and respectfully disagree.

I stand by my recommendation based on my own experience. Unfortunately, cam belt failure is not an “extremely rare occurrence” as suggested. I have seen the carnage this can cause many times! My recommendation is for GL1000 models only. I defer to others on GL1100s, GL1200s and GL1500s. I suspect you can go a bit longer on the belts on the later models because they have lower redlines.

The normal automobile recommendation for 4 cylinder cars is typically 5 years or 60,000 miles. I submit that the GL1000 engine puts more stress on it’s belts than a typical car does (via higher performance cams and much higher redline.) There is no definitive, non-contradictory recommendation from Honda regarding GL1000 cam belt interval. I’m quite happy with the conservative recommendation I make. In any case, belts are cheap compared to bent valves (and worse).

When you decide to change your belts, these aftermarket belts are suitable replacements at lower cost than the OEM Honda belts:

Gates #T274

NAPA #250274

Goodyear Gatorback #40274 (available at AutoZone and others)

Randakk’s also offers excellent replacement timing belts.

There are excellent step-by-step description with pictures on how to change the timing belts on the Naked GoldWings Forum

Search in the ShopTalk area then select this thread by Octane in the Timing Belt section.

I recommend free registration with the Naked GoldWings Forum to access the complete wealth of specialized information available via that site!

This information is courtesy of Lars Nielsen, aka “Octane” – Denmark. Lars is an internationally famous GL1000 enthusiast and prominent technical contributor to: Naked GoldWings Forum Thanks Lars!

Tip: contrary to most advice, it is not necessary to remove the the radiator and hoses when replacing the timing belts if you have access to this handy tool!

Tip: always adjust final belt tension with the engine fully WARMED from 20 minute+ ride. Per above – always let the springs do the work…don’t “help” them any.

Boxer engines “grow” due to thermal expansion and you will over-tighten cam belts, shorten their life and cause whine if you don’t accomodate these physics. On a GL1000, incorrect belt tension will also corrupt ignition timing since the timing apparatus is driven off the left cam not the crank as in later engines. Thus, belt tension has to be perfect BEFORE you mess with ignition timing. In my experience, many timing belt tensioners are needlessly replaced to correct “whine” cause by improperly tensioned belts.

Comments

  1. Slience since 2013. All speak of changing the idler pulleys but no one list a part number. Napa dont have them for something.?
    78 gl 1000.

    • Norton Muzzone says:

      We can assist with giving you the OEM part number 14510-371-008 for the idler pulley. There are two required. They can be located by an internet search with that number.
      Thank you for your inquiry,
      Norton
      Randakk Customer Service Team

  2. chad zayco says:

    hello! Gates belts came saying i need to replace tensioners, idlers and water pump whenever i change the timing belts. Please can anybody clarify this? my bike’s a 1975 GL1000.
    Thanks,

    Chad

    • You can safely ignore that advice from Gates. That was intended for automobiles using the same belt. The idler rollers do need to be inspected and evaluated for proper function.

  3. I recently broke a timing belt riding a ’77 through my neighborhood. I was hoping I would have no damage due to it being at a low RPM. I checked compression: cylinders 2 and 4 had 140 and 135 psi while 1 and 3 had zero. Any ideas why both cylinders would have zero? Bent valves I assume?? Any ideas where I can find valves as they are obsolete from Honda??
    Thank you.

    • Yes. You have bent valves on both of those cylinders. Good aftermarket valves are available from many online vendors including Sirius Consolidated.

  4. Eric Ellquist says:

    Hi, just bought my first Goldwing, a ’78. The bike had sat for 3 years in a garage, and so far as I know had not been started and run at all. The previous owner had a medical condition which made it no longer for him to ride. After a a few years, he decided to sell, to someone who wanted to ride it rather than scrap it, or part it out. I’m 65 yoa and need a more comfortable and reliable bike than my old BSA bitsa (bitsa this bits of that). Anyway, the plan is to clean it up and replace the things that have degraded from sitting, belts, hoses, points, plugs, etc. So, I checked out the piece by “Octane” on replacing the timing belts, and I have one question about that. What is the life span of the adjustment springs? In other words, do they weaken over time to such a degree that their ability to tighten the tensioner wheels sufficiently is suspect? I am amazed by the amount of available Goldwing info, I have yet to ride a Goldwing, but I suspect that when I do, I will find out why this is so… Thanks, Eric

  5. When I first started working on my 1978 GL1000, I knew the timing belt would probably need to be replaced. I went ahead and ordered a belt, but when I removed the cover, the old belt was actually in better condition than the new belt. The new belt I ordered seemed as if it had been around on the shelf for a while (not in bad shape), but the old belt seemed as if it was fresh off the factory line, or close to it. The bike had been stored under a pile of junk in a fully enclosed barn (not much moisture) and many of the rubber and all of the leather components were in perfect condition after cleaning (of course the 29 year old gas was a completely different story in the carbs and fuel tank). What is you opinion on this timing belt? I know by all reason, being probably as old as the bike, it should be replaced. However, I inspected the entire belt. I don’t know if I should replace it with a belt that is not in quite as good condition.

    Thank you

  6. Todd Kollman says:

    Upon inspection, both tensioner pulleys on my 78 GL have what black marks on them giving the appearance that they have seized and the belts slipped on them???? the right side belt still has the original Honda Belt logo on the od but the left side logo’s are completely rubbed off. I intend to replace both belts but whats up with the idlers? Your input?

    Thanks,
    Todd Kollman

    • Carefully inspect the idlers for bearing slop, binding, etc. A fair amount of rubber will “transfer” from the belts to the idlers over time. Whenever there is ANY doubt, I replace the idlers. Adjust the belt tension (cold engine) using the correct procedure (consult the Honda manual), then – RESET the tension again with a warm engine. This prevents over-tensioning the belts which is the leading cause of failed idlers.

  7. Thank You.

  8. NAPA has availability on the timing belt, 250274 but it’s listed for an ’80-83 Goldwing item. I have a ’78 1000.
    They list it as an 87 toothed belt, is this correct?
    I don’t want to remove mine until I have the new ones in hand.
    Thank you

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