Advice on engine "ticking" sound on my 99 CR125

[crrod]

I just bought this 99 CR125, it is my first 2-stroke (other than chain saws and weed eaters:)). I've noticed, as I get more used to the bike, that the engine has a "ticking" sound at the lower RPM. Don't notice it so much at the upper. I've searched and searched this forum, and I know that other than pulling the jug and checking the tolerances, there is no other way to be certain on how much of this noise could be piston slap.

The engine looks practically spotless, save for a little ooze coming out around the exhaust (it was missing one of the exhaust pipe springs). When cold, the engine starts first kick. The engine noise seems to be there whether cold or warm. On occasion, when warmed up, I’ll have to put it in 3rd and push start it, which is does easily and as soon as I let out the clutch. Other times, more often then not, it fires right up with the kick start. It has an FMF Fatty pipe and a Shorty silencer). The bike runs awesome, as far as I know (like I said, never had one before). The only thing I have to compare it to is a friends 2000 YZ125, which was supposed to have 10 hours on a new top end, and just doing a short drag race, neither bike separates from the other. I was sort of using this as a guide, figuring my engine was performing relatively well.

I've read that the Honda's have a tick to the engine, and that the aluminum frame amplifies this. I just don't really want to have to do a bottom end sooner than necessary. I was planning on doing a top end this winter, but perhaps I shouldn't wait? Am I being to paranoid?

When I decide to do a top end, is it best to pull the jug, have it miked and then order the appropriate top end kit, depending on if it will need bored?

Any adivce?

BTW, since I've become aware of this ticking sound, I haven't had a chance to compare the endine sound to that of my friends YZ125. Which I intend to do.

 

[da40ozthreat]

It sounds to me like typical bike noise. It is a possibility that your exhaust is leaking a little at lower RPM and may be adding to the sound. With my experience with Hondas though they due tend to be a little noisier at idle making a kind of racheting noise. Another thing that may be adding to the noise is poor fuel causing the dreaded pre-detonating ping. My overall advice to you is that you remove your exhaust and take a flashlight and look into your cylinder at the piston, rings, and the cylinder. Look for any excessive wear to any of them and this will give you a relative feel for the condition of your top end. If every thing checks out there and the bike doesnt get louder with higher RPM it is safe to assume that it is in good running order.

 

[crrod]

Thought I'd just keep my own post updated.

My friends YZ125 didn't have 10 hrs. on the new top end, it didn't have any. So it now probably has about 5. We just went and listened to his bike, and while the motor is quieter, it still has the exact same noise, just not quite as loud. So perhaps mine is fairly normal.

I got a compression tester, will do that this evening. When I first bought the bike, I stopped by the local Honda shop and one of the mechanics came out and noticed the oil at the exhaust pipe connection. He mentioned it then, but I really didn't give it another thought, but he said I should remove me exhaust valves and clean them, it appeared to him they might be carboned up and allowing the oil to seep by. What got me to thinking about this was a Clymer manual I borrowed. It specifically mentioned carboned up vavles as being a reason for hard starting. Checking and cleaning these valves appears simple enough so that is what I am going to do first.

 

[crrod]

It sounds to me like typical bike noise. It is a possibility that your exhaust is leaking a little at lower RPM and may be adding to the sound. With my experience with Hondas though they due tend to be a little noisier at idle making a kind of racheting noise. Another thing that may be adding to the noise is poor fuel causing the dreaded pre-detonating ping. My overall advice to you is that you remove your exhaust and take a flashlight and look into your cylinder at the piston, rings, and the cylinder. Look for any excessive wear to any of them and this will give you a relative feel for the condition of your top end. If every thing checks out there and the bike doesnt get louder with higher RPM it is safe to assume that it is in good running order.

We must have typed at the same time! Thanks for the idea of checking inside the exhaust opening to inspect the cylinder. I will do this as well as check the exhaust valves. "Racheting" is a good way to describe the sound, and it is exactly the same sound as the YZ125 with a new top end, only the Honda is a bit louder. It goes away, or is not as noticable when it is reved, and is most prominent when it winds down from the kill switch. I'm feeling much better about the bike after listening to the YZ125. I'm now back to being hopeful it can last me well until the winter and then I'll do a top end.

 

[crrod]

Well, I am cleaning the exhaust valves at the moment. There di not appear to be any clearance between the E-clip and the valve guide, but I decided to pull them anyways. There is some carbon build up on both the end of the valve and the guides. The linkage was operating smoothly. I examined the piston, ring and cylinder (what I could see of everything through the exhaust port, and the vavle openings), and everything looked nice and shiny. No marks anywhere on the piston or ring (only a single ring), again from what I could view. I could still see the cross hatch marks in the cylinder.

I warmed the bike up before I tore it down to check the compression. The guage I was using would register 120 PSI with every check. I will recheck after assembling the cleaned exhaust valves (hoping it improves a tad). I am suspecting that the engine hasn't ever been in to, there are no tale tell signs of a wrench ever having been on any of the nuts and bolts. I am going to order a new top end set for it and put it in when I have a free weekend. But for now, will ride it the way it is, taking it easy.