Is this cam OK to use?

[my-79-750-k]

OK, so I got a TX500. One of the lobes has some scoring/deep scratches on it. A new cam is $150, a regrind is $130, a used cam is $25, and would probably need to be reground. I paid $300 for the entire bike. So, I need some real world opinions. I have no doubt that I will replace the cams eventually, but for the time being, does this look like it's too far beaten to use without any serious concern? The other 3 lobes are in good condition for 16k miles and I have no question they would be fine, it's only the #1 intake lobe.

 

[barnett468]

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it looks bad . . if you can easily feel fairly deep grooves, its junk

 

[my-79-750-k]

Lucky for me I found out that the XS500 and the TX500 share the same engine in essence, and the cams are the exact same part, which is good, because "TX500 cams" are like hens teeth on eBay, while "XS500" cams tend to be in very good condition and reasonably priced.

 

[barnett468]

Lucky for me I found out that the XS500 and the TX500 share the same engine in essence, and the cams are the exact same part, which is good, because "TX500 cams" are like hens teeth on eBay, while "XS500" cams tend to be in very good condition and reasonably priced.

xlnt . . you will need to throw that shim out and check the clearance on ALL the valves after you put another cam in.

also, try to find a perfect low mile one.

 

[my-79-750-k]

That's Def the plan. I mean I gotta pull the cam anyway, might as well pull both and do an entire top end inspection while the chain is off.

 

[cxman]

when you buy a used cam make sure the seller marks the cam follower and lobes and keeps them matched

and you install them matched if not you will get the same rapid wear as the mismatched parts mesh

so you need both not just the cam

 

[DohcBikes]

when you buy a used cam make sure the seller marks the cam follower and lobes and keeps them matched

and you install them matched if not you will get the same rapid wear as the mismatched parts mesh

so you need both not just the cam

This is true but not the end of the world. At the very least you will need to replace the follower that was under the lobe we see. If the other lobes are visibly worn, then the followers under them also need replaced. Once the hard facing has been compromised it's a done deal.

Then obviously make sure your clearances are adjusted correctly and the cam is not dry on startup.

 

[cxman]

if you replace the follower on the worn lobe you will accelerate the wear on the cam lobe as it is already thru the facing

so you will grind down the new follower and wear the lobe even further

its a bad plan

 

[DohcBikes]

if you replace the follower on the worn lobe you will accelerate the wear on the cam lobe as it is already thru the facing

so you will grind down the new follower and wear the lobe even further

its a bad plan

I think you misunderstood me.

I am not suggesting to just replace the follower. Cam replacement sounds like it is a done deal, as it should be because the cam in the pic is garbage. I am simply saying that in addition to the cam, at least the follower under that lobe should be replaced. I would replace them all.

 

[cxman]

yes sorry i misunderstood

new cam new followers

used cam matching place followers or the used cam is junk very quickly

 

[my-79-750-k]

Agreed. I'll be getting a new follower/rocker under the left intake lobe for sure. Once they're out I'll be sure to check the rest of the followers and all the bearing points will be mic'd to make sure everything is kosher.

 

[jimmer]

Pretty sure I have a bag full of good cam followers you can have for shipping,let me know if interested.

 

[cxman]

you cant put a new or used cam follower on a used cam lobe all that will happen is you will destroy both

 

[DohcBikes]

you cant put a new or used cam follower on a used cam lobe all that will happen is you will destroy both

Your thinking is a little extreme.

In the real world, if both components are in good condition with hardfacing remaining, it is not necessarily going to destroy either component.

This is not speculation.

 

[barnett468]

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the main, criteria, is that both the cam and the rocker are smooth . . if they are, then you can certainly mix and match components . . is it ideal to use the matching rocker and cam lobe?...yes, HOWEVER, this is mainly only necessary if they show obvious signs of wear, but if they show obvious signs of wear, then unlike some people i replace them....why?...because they show obvious signs of wear.

i think many people confuse this issue with that of hydraulic lifters and cams, where it is an incredibly bad idea to mix used lifters up on cam lobes.
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its also helpful to use high quality engine oil instead of the cheapest swill oil one can find on sale.

.

 

[my-79-750-k]

Surprisingly the oil I pulled out of the engine when I first got it was fairly clean, not burnt, and had almost no metal shavings in it at all. High quality oil will of course be going in it when I finally fire it up.

and Jimmer, I will definitely keep that in mind. I know I'm going to need at least 1 follower, once I get some time and the guts to break the cam chain, I'll know whether the rest need to be replaced.

 

[crazypj]

When a cam is that worn the hardening has probably 'gone' so will wear real quick and deposit metal into oil