Honda XR250(Engine Noise - Tappets)

Hey guys just a small question about the engine and the engine noise that my XR250 makes. I am just curious as to if the XR250 engine is meant to sound sort of louder then that of my old XR100 since its a dry sump instead of a wet sump.

But more or less the answer i am looking for is since my old man redid the tappets or valve clearances or what ever its called my bike has a distinct tick to it on some days and nothing on others as he set the clearances to 5 thou since they hadn't been done by the previous owner and were down to 2 thou.

Just looking for advice since it is set to 5 thou which is between the 4-6 thou recommended range i presume that this is ok and its just the tappets going up and down at a different position.

Sorry if this doesn't make much sense as i just would like a quick answer as to if this is ok as i don't want to damage anything.

Thanks Guys

Matt

XR250R 1996 to 2001

0.10 +/- 0.02 mm 0.004 +/- 0.001in (Intake)

0.12 +/- 0.02 mm 0.005 +/- 0.001in (Exhaust)

The manual states the Exhuast tappets shoud be 5 thou and the Intake tappets 4 thou, both within a range of 1 thou.

If he set them to 5 thou then that should be okay, providing the stroke was at TDC when he set them.

If you are unsure and want to reset them then follow this thread. It certainly helped me the first time I adjusted mine.

http://www.thumpertalk.com/forum/archive/index.php/t-355094.html'

Is it still happening? If the tappets are set correctly it could be to do with the petrol you are using. Try search for pinking/pinging and you should find out why.

Do these measurements also apply for the 2002 model, if not do you know where i could download the manual for this bike?

Well lockness its a weird thing is that on some days i can here the tick sort of noise where as on other i cant and when its idle i cant hear it but when im going along i can. My old man set the tappets to 5 thou when i was at work but this weekend hopefully we can check them and change if needed. So definitely 4 thou on the intake and 5 thou on the exhaust?. Is this what you use and also what the book recommends?

Thanks M8

Matt

its more likley to be worn sub rockers.the adj screw wears a hole into the sub rocker,so when you use the feeler gauge you cover the hole(or worn spot)and get an incorrect setting.

in other words, if you have a worn area on your sub rocker of .003" plus your feeler gauge of .003" then you have a total of .006". more than enough to make a ticking noise.

Sometimes,if my XR250 has"nt been cranked for a while,it will tick a little bit when first started,but once the oil gets pumping good,and it"s warmed up good,it sounds great,no excess noise whatsoever,I do change the oil at 400-500 miles,period,and it runs beautifully,Im happy.

I have an 1996 XR250R that I set the exhaust at .005 & the Intake at .004, It also makes a tapping sound. I agree with the worn sub rocker but my bike starts first kick so until I do a top end job on it I'm going to ride it.... Runs great. 1st, 2nd & 3rd wheelies..... just noisy

Or in my case, not ticking upon start-up but does when it warms up. I generally use Honda G4 or something in summer 20-50 and 10-40 when it gets colder. Should I change oils? BTW, it starts fine but is still cold blooded after a Gordon mods (I did upsize the jets).

If your bike has a lot of hours on it, you may be hearing the cam chain slapping. If so you will be surprised at the mount of crisp power that returns with a new chain.

any chance the auto decomp is causing the noise?

You might have worn cam bearings bud.

Ive just finished a top end rebuild on my 2002 xr250 and i found my cam bearings to be well worn, i replaced them and now its much quieter.

I actually locktited mine onto the camshaft because they were a very loose fit and i was worried they could slip and wear.

I suggest you whip off your rocker cover and check em out.

If you do, i recon your best bet is to cable tie the cam chain onto the camshaft sprocket nice and tight, that way you wont mess up your timing or drop the camchain down into the crank case.

When the chain is secure, just lift the camshaft out and slide off the canshaft bearings (noting which way round they go) then check them for lateral play, and check they spin freely without graunching.

If they have play or sound nasty then replace em, you can get em from any bearing shop (i got mine from a yamaha dealer) the number is 6003U

:busted:

I did my valves today on my '03 XR250 today. The bike has been harder than usual to start of late, although there hasn't been any real noticeable valvetrain noise.

It was my first time doing the valves on any bike, but it wasn't too hard... although it did take some getting used to for me to feel comfortable with trying to measure the clearances properly with my feeler gauges. I basically disassembled my feeler gauge set and took out the ones I needed and bent the ends so they would fit inot the valves easily. The whole job took about 4 hours because I was going real slow and careful and most of the time was spent really cleaning up the bike and trying to get every single inch of dirt out of the sparkplug area after I pulled the plug by using PB-Blaster and a bunch of Q-tips while the bike was tipped on its side and almost upside down. This was the first time I've taken this bike apart, so it was really dirty underneath the plastics where I can't get to with the hose and rags on post-ride washes.

I was very surprised to find out that my valves were extremely tight prior to adjusting them. On the compression stroke, I was only able to move them ever so slightly and I could barely get a .06 mm feeler gauge in there the way they were set. I backed them off to the factory spec of .10 mm intake and .12 mm exhaust, and I could feel a noticeable difference in the valve play, so I put it all back together.

After the valve job the bike started on the first kick, much to my amazement..... but it makes noticeable valvetrain tapping now when cold. I was definitely surprised to see it start soo easily, considering it was 32 degrees out when I started it today, and I tried to start the bike last week one day in similar conditions prior to doing the valve job and it took about 25 kicks before it even fired at all on that day... and about another 15 before it stayed started enough to warm up.

Are they really supposed to be tappy like that? The bike seems to run fantastic after the valve job, but it's definitely noisier.

I recently had my valves adjusted on my 2001 Xr 250 hoping that that would get rid of the annoying ticking noise in the top end. Unfortunatley, the noise is still there although the bike runs great. I have been told that the cam chain tensioner could be worn causing a ticking noise. I'm not sure if this is the same noise as you are hearing??

Look at the timing chain tensioner...if it is all maximum adjustmet it is time for a camchain. The timing chain will make a tapping noise when it is out of adjustment or worn to max limit. Much like your drive chain makes noise when it doesn't mesh with your sprockets properly due to chain stretch. I would replace the chain and inspect both sprockets for wear.

Thanks for the quick reply! I am not a mechanic but I would love to dive into it and do it myself. Is it a pretty straight forward job or should I look for a good mechanic? I do have the Honda service manual to follow but I have no experience working on engines.

I recently had my valves adjusted on my 2001 Xr 250 hoping that that would get rid of the annoying ticking noise in the top end. Unfortunatley, the noise is still there although the bike runs great. I have been told that the cam chain tensioner could be worn causing a ticking noise. I'm not sure if this is the same noise as you are hearing??

The slight noise that my bike is making is definitely from the valves. The reason I know this is that it didn't really make much valve noise at all prior to the valve adjustment, and immediately after doing it, I could hear them a bit more. It doesn't sound horrendous, like something is about to break or anything... but it's just more noticeable. I think it started to quiet down as the bike warmed up, but I didn't really take it out and ride it around for very long after the valve job... just about a 5 or 6 minute session of around the yard and up and down the street a few times.

Hopefully the weather cooperates in the next few days so that I can take it out on at least a half hour ride and really get it piping hot, and see how well and quiet she runs then with the newly adjusted valves.

Thanks for the quick reply! I am not a mechanic but I would love to dive into it and do it myself. Is it a pretty straight forward job or should I look for a good mechanic? I do have the Honda service manual to follow but I have no experience working on engines.

It is fairly easy to change the cam chain. You do need a special socket to remove the clutch basket though. They are available at cycle shops or you could make one. I would take the valve cover off and look at the tensioner first to see if it is at max adjustment ans see if the chain has ANY slack at all and I mean ANY. If you can pull the chain away from the cam gear at all it is time for a chain.

That sounds like a good plan. I've gone ahead and started looking into replacing the tensioner and chain and I was wondering if you could recommend either OEM or aftermarket parts. The OEM parts seem to be a bit more dough but are they worth it?? I was also looking into a gasket and I found some on EBAY made by NE which were 1/2 the price of the Athena brand or moose racing. Have you heard of them?? 29.95 for a complete set. Sounds too cheap!! Thanks

That sounds like a good plan. I've gone ahead and started looking into replacing the tensioner and chain and I was wondering if you could recommend either OEM or aftermarket parts. The OEM parts seem to be a bit more dough but are they worth it?? I was also looking into a gasket and I found some on EBAY made by NE which were 1/2 the price of the Athena brand or moose racing. Have you heard of them?? 29.95 for a complete set. Sounds too cheap!! Thanks

I usually use OEM gaskets, they just fit better. As far as a chain I would call Powroll or XR's only, the adjuster probably has to be OEM. I am not aware of any aftermarket tensioners.

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