[Closed] Motorcycle engine tapping noise- help please!

Yeah, it's almost certainly the cam chain being too loose. I'm not 100% on Suzuki's but on many older Honda's you could just undo a nut and the cam chain tensioner would self adjust.

It could be that the cam chain has now stretched beyond use now though and needs replacing.

Thank you for the advice! It looks like an easy enough job having just looked online as there is just an adjustable spring that's easily accessible. I'll take a look. Hopefully it's nothing more serious and that it's not too much of a mess inside.

I had this with an old Honda CB125 which I had stripped and put back together. Clicking noise when ticking over, didn't really get any worse under load or reving the $alls off it.

I've a DR125 (same engine) and the tensioner is below and to the left of the carb. To adjust the tension, undo the lock-nut, loosen the stud running through, nip-up the stud & then the lock-nut (whilst holding the stud still). IIRC you have to do this at TDC, could be wrong, it's in the haynes.

However, if the guides are worn through to the metal you'll always get a noise.

easy fix..

Yes, timing chain most likely. Failing that, piston slap but it would have to be high mileage and you might have had a seizure. If it's that, a rebored barrel and an oversized piston are an easy job even for an amateur mechanic.

That is one hell of a racket.

I'm not possessed of the magic mechanic's ear, but it sounds very dramatic* for cam chain and too regular to be piston slap. Overheating on an air cooled bike could indicate oil starvation (low oil level or blocked feed) leading to something(s) getting very badly worn.

*although maybe I'm not allowing for what 30 year old bikes should sound like!

Thank you for all of the suggestions. It's 23k miles so not too bad. At least I have a few things to go on. I'll take a look at the tensioner later this evening. As you say, if the tensioner is fully functional the chain is worn but that's still a fairly easy fix. I don't think it has a record of having seized but as you can imagine, it's had a few owners before me! It contains the correct amount of oil but I'll take a look and see if the oil filter is blocked.

Is there any easy way to check if oil is being distributed around the engine? I ran the engine very briefly when checking the valve clearances and half expected oil to be thrown around everywhere with the viewing caps off but it looked fairly dry....

If your engine isn't getting any oil at all it would be apparent VERY quickly.

Sounds entirely normal but then I ride a single cylinder bmw!!!

Is there any easy way to check if oil is being distributed around the engine? I ran the engine very briefly when checking the valve clearances and half expected oil to be thrown around everywhere with the viewing caps off but it looked fairly dry....

Not a lot of oil goes up that way. The cam is supplied by an oil passage surrounding a cylinder stud, the rest of the head is splash lubricated via the chain and remnants of the cam oil. With the caps open I used to get some thrown out by the tappets. If you've got an oil-pressure gauge you can plumb it into the port just below & to the front of the oil-filter cover.

My engine was never particularly quiet. Personally, if after doing the tensioner and re-checking the valve gap (whilst cold) i'd just ride it. BTW, if your gap starts closing up, beware! I didn't clock on to what was happening and the inlet valve stem broke whilst on my way to work years ago. (I used to change gear at valve float 😀 )

@jonnouk thank you. I'll ask around and see if I can borrow a pressure gauge. It's reassuring that your DR was also a bit noisy. I've looked at videos of the GS GN DR etc online and did notice that the older ones make a bit of a racket. However, the overheating is still a bit worrying. Checking the oil filter is something that I haven't done yet so may be worth a go. The engine really struggles at low revs and has developed a bad habit of giving up and stalling as I pull away which is making it a nightmare to ride. I suspected that the problems may have been related to the engine noise.

If you're going to hookup a gauge you need an adapter from M14x1.25 (the bolt hole) to 1/8 NPT (or whatever the gauge is).

Are you sure it's overheating? I'd have no idea if the engine is as there's no sensor. If it is, lean jetting could be the cause (and explain the lower power). The plug condition would be the 1st step to check jetting.

Hi Jonno, I also can't say 100% if it is overheating. I guess I just came to the conclusion because of the unhealthy noises! The reason that I think it's overheating is that even after a 10 minute ride to the shops, I can see `smoke' leaking from the top of the engine. I suppose that you could argue that nothing should be able to leak from the top of the engine and maybe it is normal fumes meant for the exhaust. Still, it doesn't smell too healthy when I stop.... Am I looking for metallic specks on the plug? I the tell-tale signs are probably documented in the manual. Thanks again

The reason that I think it's overheating is that even after a 10 minute ride to the shops, I can see `smoke' leaking from the top of the engine.

If there's any oil weeping that could be the cause. On my bike the exhaust valve inspection cap leaked a little and oil would smoke once the engine was good an warm. If you see an oil weep around that area I wouldn't worry to much about it. Note: don't tighten up any of the 8mm bolts around that section without a torque wrench trying to stop a rocker cover oil-leak.

[url= http://ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp ]Here's how to read a spark plug.[/url]

[edit] I've just compared the sound of your bike to [url=

Nice bike, I've always liked the look of the early enduro style. Without a shadow of a doubt, mine sounds bloody awful compared with yours! I'll have a go at a few of the suggestions above and see if/ how the sound evolves...!