2017 Husqvarna FC 250 engine sound.

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10/25/2018 11:41 AM
Edited Date/Time: 10/25/2018 11:42 AM

Hello,

I have a 2017 FC 250 that is has a loud metallic tick( Video Below). The bike has 32 Hrs. The tick does not go away when I pull in the clutch (suggested test on other forums) I installed a dirt tricks cam chain tensioner when I bought the bike to get rid of startup rattle. I have inspected the tensioner and it seems to be working correctly when I play with it outside of the bike. My intake valves were a bit tight, and my exhaust valves were right on spec. I visually inspected the valve train and shimmed the valves. now all valves are within spec and bike still has the sound. (the video was taken the first startup after shimming valves). Timing looks to be correct. the bike runs quite smooth other than the metallic sound.

I am looking for any suggested next steps or possible causes.

Thanks in advance for your input.

Jared

FC 250 Engine Noise

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10/25/2018 12:36 PM
Edited Date/Time: 10/25/2018 12:38 PM

I Think it is the chain is to Lose or need a New.

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10/25/2018 12:53 PM

MadsDausel wrote:

I Think it is the chain is to Lose or need a New.

Thanks for the reply!

By chain, I assume you mean the timing chain? Is there anything special I should be looking for when I inspect it? The chain seems to be tensioned correctly. how much tension should be on the chain? The tensioner I have installed in the bike is a hybrid mechanical-hydraulic tensioner so it keeps the chain taught under startup with the use of a spring and then once the oil pressure increases it uses that.



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10/26/2018 7:48 AM

That sounds pretty normal to me. The oil level all good?

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10/26/2018 7:54 AM

CarlinoJoeVideo wrote:

That sounds pretty normal to me. The oil level all good?

The oil level may have been a tad high in the sight glass from the last change but nothing major. it definitely always had a small tick but there was a pretty abrupt change in the tick and it is excessively loud now. I thought it was the cam chain tensioner as I have already had one fail. but from visual inspection, I can't see anything wrong with it.

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10/26/2018 8:01 AM
Edited Date/Time: 10/28/2018 6:16 AM

Sounds like noisy valves. Do you have upgraded cams or excessive valve clearance? Worn timing chain, guides, and tensioners can cause this too.

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10/26/2018 8:09 AM

kb228 wrote:

Sounds like noisy valves. Do you have upgraded cams or excessive valve clearance? Worn timing chain, guides, and tensioners ...more

Stock cams and I adjusted valve clearance yesterday. pre-adjustment the exhaust was at .130 and .120 so i adjusted them both to .15 as their tolerance is .13-.18. the intakes were at .78 and .82 so I adjusted them to .125 but must have miscalculated or mismeasured because one turned out to be .15. I left it because it is right on the high side of the suggested range. Should I re-shim that one back down?

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10/26/2018 8:12 AM

kb228 wrote:

Sounds like noisy valves. Do you have upgraded cams or excessive valve clearance? Worn timing chain, guides, and tensioners ...more

lucas797 wrote:

Stock cams and I adjusted valve clearance yesterday. pre-adjustment the exhaust was at .130 and .120 so i adjusted them both ...more

If its in range its okay. Its just noisier.

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10/26/2018 8:28 AM

kb228 wrote:

Sounds like noisy valves. Do you have upgraded cams or excessive valve clearance? Worn timing chain, guides, and tensioners ...more

lucas797 wrote:

Stock cams and I adjusted valve clearance yesterday. pre-adjustment the exhaust was at .130 and .120 so i adjusted them both ...more

kb228 wrote:

If its in range its okay. Its just noisier.

Ok thanks, I will re-shim it anyway to see if I can get rid of the noise.

thanks for the input!

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10/26/2018 2:23 PM

If you have already had to shim the valves and you have not yet replaced the cam chain, it is very worn. Replace it and see if the noise goes away. I would also suggest that you use an OEM tensioner.

Paw Paw

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10/26/2018 2:31 PM

Paw Paw 271 wrote:

If you have already had to shim the valves and you have not yet replaced the cam chain, it is very worn. Replace it and see if ...more

wouldn't the cam chain last much much longer than 30 hours? on my previous husky's and KTM's I have had 180 hours on them with 1 valve shim at around 120 hours and that's all. Just wondering what would cause the cam chain to wear that fast? What is your reasoning for using the stock tensioner? Everywhere I read about them it says they are very unreliable and noisy on startup and the manual or hybrid tensioners are much better? (just a note Bike has been ridden 100% on tracks at fairly high RPMs for the 30 hrs)

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10/26/2018 5:29 PM

The use of manual tensioners means that a large part of the time the chain is actually out of proper adjustment as the adjustment is only done as the owner elects to do so where as the OEM tensioner is always in proper adjustment and extends the life of the chain. When the chain is worn out a lot of riders elect to go with the manual ones as they feel the tensioner is an issue when in fact the chain is the issue. The OEM tensioner will only adjust the chain when the chain is with in wear limits. Remember...High RPM running is hard on the valve train including the cam chain. Most manuals give a measurement for the cam links to properly judge the chains wear. Check your manual.
Also if the valves are streatching or recessing into the head so much as to need shimming then the cam chain is also wearing. This is one of the most over looked part in a modern 4 stroke MX engine.

Paw Paw

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10/26/2018 5:51 PM

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10' 200 XC-w
96' XR600r

10/26/2018 6:11 PM

Paw Paw 271 wrote:

The use of manual tensioners means that a large part of the time the chain is actually out of proper adjustment as the ...more

Thanks a lot for the info.

The tensioner I have is an auto tensioner. it is the dirt tricks one above. I will check the measurements of the links.

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10/26/2018 6:12 PM

I have that tensioner installed it seems to work great

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10/28/2018 4:58 AM

Mine made that noise when I used Rotella oil in it. I switched back to Motorex and the sound went away.

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10/30/2018 12:12 PM

swtwtwtw wrote:

Mine made that noise when I used Rotella oil in it. I switched back to Motorex and the sound went away.

I use full synthetic royal purple max cycle 10-50. been using it for about 25 of the 30 hours so I don't think oil is my issue but thanks for the reply.

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10/30/2018 12:27 PM

Paw Paw 271 wrote:

The use of manual tensioners means that a large part of the time the chain is actually out of proper adjustment as the ...more

So I have been busy and finally got to pull the valve cover off again and check out the cam chain. I cannot find a link measurement spec in my owners manual. The tensioner I am currently using is a hydraulic auto tensioner that uses a spring and a ratcheting mechanism to keep tension when there is no oil pressure. The ratcheting mechanism keeps the tensioner locked in the extended position when I remove it. This allowed me to see how far the tensioner was extended while in the bike. It was about halfway through the available stroke. This makes me think that my cam chain must not be stretched too much as the tensioner should be all the way extended for this scenario. Before I removed the tensioner I felt the tension of the cam chain and it seemed like it was tensioned well as I wasn't able to move it much at all.

Please let me know if I am correct in thinking that my cam chain probably isn't worn out with the newfound info.

Thanks for all the help

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10/30/2018 1:10 PM

Look in the service manual for the cam chain spec's.

Paw Paw

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10/30/2018 2:00 PM

Paw Paw 271 wrote:

The use of manual tensioners means that a large part of the time the chain is actually out of proper adjustment as the ...more

lucas797 wrote:

So I have been busy and finally got to pull the valve cover off again and check out the cam chain. I cannot find a link ...more

A roached cam chain will have links that bind up. Also your marks on the cam gears wont line up with the head gasket surface. Doesnt require a measurement. You can easily tell when its bad.

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10/30/2018 2:18 PM

kb228 wrote:

A roached cam chain will have links that bind up. Also your marks on the cam gears wont line up with the head gasket surface. ...more

As far as I can tell it rolls quite smooth with no binding and the timing marks are accurate. Any other suggestions of what I should be looking into? ( i took the measurements of the chain anyway and will continue to look into the chain)

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10/31/2018 1:07 PM

For the record, my 2015 250 SXF makes the same noises, and I have the dirt tricks cam chain tensioner installed with OEM valve shims that are smack dab in the middle of the tolerances.

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10/31/2018 1:21 PM

Kanewel433 wrote:

For the record, my 2015 250 SXF makes the same noises, and I have the dirt tricks cam chain tensioner installed with OEM valve ...more

I'm worried about it cause it was a fairly abrupt change in sound while I was on the track. It has always had a small tick of the same sort but it got exponentially louder over 1 day of riding.

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10/31/2018 1:25 PM

Im just throwing it out there.. i had my preload adjuster nuts on my shock come loose once. The sound of my shock spring rattling made me think something was wrong with my engine. Maybe look for loose parts? That kind of noise doesnt all the sudden happen. Its usually gradual.

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10/31/2018 1:53 PM

kb228 wrote:

Im just throwing it out there.. i had my preload adjuster nuts on my shock come loose once. The sound of my shock spring ...more

Thanks for the reminder. below is a video of me turning the bike over with the valve cover off. let me know if anybody sees anything with the cam chain that I am missing. seems to be taught and rolling quite smooth.

Turning fc 250 over

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