Slightly tatty cb500

Hello all,

I am still pretty new here but I have really appreciated the advice I have been given so far. I recently bought a 1998 cb500s that is relatively high miles (54k) and is tatty but with a really strong engine. As I won't be licensed to ride it for about another month, I have set to tarting it up a bit. I have done the usual oil and filter, flush cooling system, bleed brakes, change plugs and the like. Tyres are good, battery is good and all electrics are working.

The bike was sitting unused for a while before I bought it so I was wondering if anyone has any suggestions about work that might be due. I have no receipts for it so I have no idea what work has ever been done on it. I have noticed the fan doesn't come on when it heats up so that will be my next investigation. Can anyone else confirm that it should come on before the temp. gauge gets to 3/4 and does anyone have suggestions for other checks or work to carry out? I have seen threads about valve clearances at that milage that made me worry a bit.

Any thoughts welcome!

Sounds like you've got a decent going bike and no need to fix things if they ain't broke.

Cooling system:
Does the temp often rise above half way? Most hardly rise above bottom of the clock at all as these bikes run fairly cool. But if temp does go up half way or more without activating the fan, you might want to check the stat and the fan switch & wiring. Do a search on here - plenty good info on this.
Valves:
Supposed to be checked at 16k intervals (I think) but if the bikes goin ok and starting hot ok then there's probably not much wrong with them. Give the mileage tho' (and no service history I assume?), if it was mine, I'd want to be havin a looksee anyway.

Cooling fan on these bikes tends to come on when it's high up the thermometer, yes. I expect you're running the engine with it stationary, which would be why you're seeing it warm up like that.

Valves would be a very good call, you want to know when it was last done, and this is how. It's job that keeps your bike off the road while you order new ones, and as you aren't depending on it for transport now, you may as well get it done. I took mine apart one weekend, ordered new shims which arrived in the week, and put it together again the following weekend.

However, you've just changed the oil. It's ideal to do this job after working on the valves, in case dust and shite falls in the engine while the cover is off. You run it afterwards to hot the oil up and flush the dirt out, then change it. You can either ignore this advice, or view this fill of new oil as a flush to clean the engine.

As the bike isn't on the road at the minute, I can't make any comment on how hot it getting general use but I did run the temperature up intentionally on the driveway to check if the fan kicked in and I ran out of courage 3/4 of the way to the top end of the temp gauge. I live in London so temps will get higher than most users but no idea how much yet. I certainly would like the fan to work though as it might not take a lot of strain to kill my relatively high millage engine even if it is in good shape now.

What's a rough mechanics cost to measure the clearances and change the shims. Removing the cam shaft et al is a bit advanced for my mechanics skills!

liverpool_f_ wrote:What's a rough mechanics cost to measure the clearances and change the shims.

It's nearly all labour so you'd be probably get better info just phoning around a few independent bike shops in your area to get "all in" fixed prices. Their labour rates should be considerably lower than Honda dealer rates.
What ever you do, don't give the job to someone on an hourly rate basis.

One thing you could do if you haven't already is suss out what sort of nick the chain's in. Clean with fresh rag and/or bog roll, plus liberal amounts of diesel or GT85 if you're loaded, then lubricate it using it thick gear oil i.e. EP90. Leave it for a day, then repeat. Now check for tight spots - how much play at the tightest spot (should be about inch and a half top to top iirc), how much give at the loosest. If there's loads of sag - like 3 or 4 inches - consider replacing. Cos from what I see on other bikes at cafs there's a lot of neglect going on especially since everyone's switched to dry lube (an oxymoron if you ask me but hey).

As for the fan, it takes a while to flick on so I wouldn't actually worry about that. However, do have a gander at the plug connecting to the rad (check for wear, corrosion, will it unplug easily, etc.), because they are exposed to the elements and liable to rust, die and drop off.

This may be hard to assess for someone who've not yet ridden the bike, but how about the front forks? Apparently, maintaining front forks is a job done way too seldom, meaning your '98 bike probably hasn't had its forks done in years. I bought mine with a set of worn-out fork seals (thus leaking), so I can vouch for the effect of doing the forks up.
You'll need a set of seals, one liter of fork-oil and possibly a set of sliding bushes. And an afternoon with nothing else to do

Next suggestion: oil your cables. You may not think it will make a difference - until you've done it! I got hold of one of these gizmos, which enables you to pump oil into cables.


You got the Haynes manual? Working on the bike with one of those within reach is a good thing.

All good ideas and enough to keep you occupied until you've got a licence!

Just one point to note: you don't need to take the cams out to *check* the valve clearances, you just need to remove it if they need adjusting (by changing the shim size).

So, if you are so inclined you can take it apart (normal tools - sockets, spanners etc), check the clearances (using some feeler gauges) and then you will know how bad the problem is (or isn't) - at this point, if the clearances need adjusting you can decide if you want to fix it yourself or if it is worth paying someone else to do it (but at least you know what you are paying them for).

Cheers guys,

That is all pretty sound advice. The chain and sprocket were in pretty gross condition so I did spend quite a while de-crudifing them. They are probably not in the best nick but will do for a while. The fork seals are also knackered as someone pointed out but as I bought it from my mechanic, he said he would do those for me for free when the bike was on the road.

One other point. The down pipes were fairly rusty so I had at them with a wire brush drill bit with the intention of painting them with high temp paint. The brush removed all the lose surface rust but they still aren't exactly shiny. Will the paint still take and does anyone on here use heat wrap with a waterproof coating instead?

liverpool_f_ wrote:As the bike isn't on the road at the minute, I can't make any comment on how hot it getting general use but I did run the temperature up intentionally on the driveway to check if the fan kicked in and I ran out of courage 3/4 of the way to the top end of the temp gauge.

The fan should come on when the needle gets just over half way. The most common fault is the earth wire snapping off, it should be on a crimp screwed onto the top rad fan screw. If you can't spot it look for a black wire floating around!

After doing the fork seals replacing the fork oil with new made a big difference to my bike's front end. 
You could fit new shocks if the old ones are knackered too. 
And a new air filter and check the sub air filter, mine was in pieces when I got the bike.
Take the plug out of the breather pipe and let the gunge escape.