Important Harley twin cam info

The redneck that lives two doors down still has to stand on his chipped and piped powerstroke to get it to move.

They belong to poor people who don't ride. They sit around and develop carb problems, won't crank, and then become the "I got a Harley" in the garage that never sees light.
Or they get eBayed the way all the Buells are.
Used to see a ton of 750fours around, and now they're the same place. In some guy's basement, or sold one piece at a time online.

I always have my ear to the ground for a Honda four. I used to have my pick. Same for evo sportys. Not so much any more.

I happen to have a solid mount evo sporty (03) and a evo dyna (97) and ride the wheels off both of them I had a buell too but it went to an early grave. Btw I'm also "poor" but do my best to provide for my family and if I have to sacrifice some riding to make that happen then that's what I'll do. I don't have a harley to say "I got a harley" I have them to ride as a "poor" person I have no need for something that I can't/don't use it's an extra expense that I can't afford.

I guess I took a little offense to your comment I probably shouldn't have I'm sure you meant no harm it's just your perception.

The Vision is sweet though.

Like limburger cheese.

Oh, another kool-aid drunk girly man...never mind...

Some of the 88's had cam chain issues but most didn't. It depended a lot on the way the bike was driven and any mods that the engines had done. I've seen some 88's with 50 K miles with still a lot of wear left on the cam tensioner.

With gear driven cams you are going to get the wine, listen to a gear driven VFR. As the engine wears the cam chain is much more forgiving if there is any cam/crank variance.

In all engines with a cam chain it has to be considered a wear item at some point in time. With air cooled motorcycle engines they are subject to more variance in their heat/cool cycle throughout their life so I wouldn't find it odd that a cam chain tensioner had to be replaced at some point in time. On many of the older Japanese bikes with adjustable tensioners when you got to the end of the adjustment you had to change the chain/adjuster.

I think modern oils, speaking with synthetics, help to control this wear to an extent but everything wears out, you and me included.

I have never worn out a cam chain on anything.
On older bikes, the tensioners could wear or break, but I never had a chain wear out.
Its in clean oil!
Never really wore out a primary chain either.

I had a 1986 883 sportster in 1986, and they do seem kind of rare these days, there were a lot of them around back then...

They're alive and well in CT. All over the place. Can't throw a rock without hittin' one.

Sure isn't the case in BC. Seems like any bike over 5 years old is a rare sight.

"kool-aid drunk girly man" is only applicable to BMW riders n00b.

Having been employed by a Harley dealer since 1998, I can say that the cam chain tensioner failure problem was almost exclusively a problem on the '99-'01 models. Best and probably easiest solution was just to upgrade to aftermarket gear driven cams.

I disagree. I'd say the description fits the pirate quite well.

It's applicable to any man that chooses pretty over performance, and/or form over function....

Don't fight it man, embrace it...

On the plus side, it's super easy to inspect the tensioners by pulling off the engine right side cam cover. On some touring models you also have to remove the right hand pipe and footboard. You can lift the top tensioner shoe off the chain and look at it easily. For the other one you'll need an inspection mirror like a dental mirror. The problem appears as excessive wear and pitting in the plastic shoe material. Some speculate prolonged idling with the bile on the sidestand deprives the cam chain of oil and leads to earlier failures.

the cam bearing problems were on the first two years of the new twin cam motor 99-2001 models and do not affect later model bikes. The tensioner problem surfaced with the late 2003 to early 2006's. There's some pretty good info going around that the problem was traced back to the dies used to stamp the chain links out leaving burrs on some links. As late as 2011, my local dealer was replacing the infrequent failures on low mileage bikes and covering the labor for doing so.

Unfortunately, going gear drive is not always an option if there is excessive crank runout aggravated by doing away with one of the two tapered roller bearing on one side of the crank starting with the 2003's. and using a roller bearing in it's place. If you are considering gear drive cams, sites like SS and Andrews have instructions for measuring run-out and different part numbers for cams with gear sizes to match what you measure on your motor. Harley themselves came out with a new redesigned cam bearing plate incorporating new hydraulic tensioners along with a high flow oil pump that is easy to retrofit to older bikes.

I inspect mine annually, 45K miles and no problems so far on 2005. For bikes with the problem, it is pretty evident it exists at 10-15K miles by the condition of the tensioner shoes. BTW, the Twin Cam motor went to chain drive to pass EPA noise drive by specs.

The nice thing about HD is they are like Chevrolets, parts are everywhere from multiple sources.

I have a 1964 Ford 200 ci straight six with over half a million miles on it. The head has never been off (been in the family since new, I am now the proud owner) It is starting to burn a little oil, but timing is still spot on, it has a geared cam drive. Still has good compression, I think the valve guide seals are leaking. Oh well, helps lubricate the valves.

The average lifespan of a timing chain/sprockets on a '70s American car is under 100,000 miles. That is still true, even if you replace it with a new 2012 timing chain. Ford, GM, and Chrysler used PLASTIC cam sprockets supposedly because they were quieter. When the chain got some excess play in it, it quickly stripped the teeth off the sprocket and destroyed the engine. If you replaced the cam sprocket with a steel one, and replaced the chain every 60,000-70,000 miles, these engines, properly maintained, could easily last half a million miles. That's five times as long as the stock chain and sprockets would last. People said the engines were no good because few made it much past 100,000 miles. Most of the reason for that was cam drive failure, either total failure, or running the engine for thousands of miles with the timing way off because of the worn chain, before it finally failed. My inline six has no chain or plastic sprocket, so it did not fail.
Very few motorcycle engines make it past 100,000 miles. The most notable exception is the Goldwing. The main reason those engines last so long is because they use cam drive belts, which must be replaced on a regular basis. They do have a primary chain, which unlike Harley's, runs inside the engine case. This is a HUGE chain, way bigger than it needs to be. But since it drives the transmission, the engine will still run even when it gets worn. You just get more driveline lash and clunkier shifting, They also have a starter drive chain, which, even though it is only used for starting the engine, tends to fail around 100,000 miles. It doesn't do any damage, but you have to pull the engine and remove the back cover to replace it. This was just bad design on Honda's part. A direct gear drive would have been the way to go.


Because My beloved Vulcan 750 has FOUR cam chains, and 74,000 miles, I have good reason to expect a catastrophic engine failure in the not too distant future. Replacing these chains requires a total engine teardown, including splitting the cases. When it fails, I'll just replace the bike. I always new it was disposable. What I like about Harleys is that they can easily be rebuilt over and over again. The old EVOs would last about 100,000 miles, you took them apart, honed the cylinders, replaced the rings, replaced the bearings, and put them back together again. Everything could be reground/rebored, and bearings/pistons/rings came in several under/oversizes. You could rebuild the engine about 5 times before you started needing to replace expensive parts. That is no longer the case with the twin cam. When the cam drive fails, it tends to destroy a lot of expensive parts. And I have been inside the twin cam engine. The chain is smaller than a bicycle chain, and the tensioner is somebody's idea of a joke. If they were going to use a chain, it should have at least have had a manual tensioner. But, since the cam drive assembly is so easy to get to, you can still save your engine by replacing it every 20,000 miles or so. It doesn't say that in the book, but it will make your engine last many times longer.

Time to give this up for the night and get ready for bed. Need to be up at 5:00 in the morning to go to my job that I have had for the past 35 years, as a professional auto mechanic.

That explains why you sell so many timing chains. Some of them might even need replacing!

By the way, the GL1800 uses timing chains. That engine has been powering Gold Wings for the last 13 model years, with many, many examples passing the 200,000 mile mark. Timing chain failure is unheard of.

I was a Professional Auto Tech for 20 years. After that I was a Service Director over three Harley dealerships for almost 10 years. I can't count the number of broken timing belts I saw, complete with valve heads broken off and driven through pistons, necessitating short block and cylinder head replacement. Timing chain replacement was significantly less common and was usually of the overhead cam variety with a perfectly good chain but broken plastic chain guides.

I saw a few chain tensioner shoes fail in the Harley twin cam engines, and even saw a couple fail catastrophically. But it was quite rare, especially compared to the sheer number of bikes out there. In terms of sheer reliability, the EVO was a huge step for Harley but doesn't even compare to the robustness of the twin cam. How quickly people seem to have forgotten the EVO weak spots.

I'll keep that in mind for the next time I'm in the market for a 70's era American car.

Yeah, the twin cam is hardly on par with a 70's American v8. I used to see a lot of broken down Evo big twins on the road. Hardly ever see a TC on the road with a component failure beyond the rider not checking the oil or something stupid like that.

I ride an Evo.