Engine Noise

[tsal]

Hi All!
Just picked up a 1979 R65 w/29k today. Motor seemed quiet when I test drove it this afternoon. Got it home, and now after a longer ride today I am getting a nasty noise coming from the engine only at idle. Go's away at 1500 rpms and up. Seems to only do it after motor warms up.  Hoping it is just valves needing adjustment. Took a short vid of it here: (you will need to to copy the link to your browser as this board will not allow me to link until after 2 posts

youtube.com/watch?v=e2_JE5g754c

This is my first airhead so...............
Thanks in advance for any thoughts/comments

[MrRiden]

I'm suspecting the needle rollers have come out of the left jug exhaust rocker [just because it's louder in the front]. Pop the valve cover and keep an eye out for stray metal bits. Examine the rocker for play on the shaft. Keep us posted!

[proctorls]

Tsal,

This sounds like a nasty introduction to the art of airhead maintenance.  I agree with MrRiden, and if it's bad news, at least you'll know immediately.

Find out from the previous owner if top-end maintenance was done recently.  Perhaps something was left loose, or, worst-case, the rocker shaft assembly was installed upside-down (or backwards, I can never remember which, which is why I have 2 shop manuals).

If the latter, the mechanism would have run fine for a while (test ride), but eventually the residual oil would heat up, run off, and leave the steel to meet the steel, with noisy and expensive results.

Needless to say, you should also check the other head for damage or misassembled parts.  If you have any question about what damaged or worn-out precision parts look like, you need to find a good mechanic.

Keep us posted.

[Rob Valdez 79 R65]

If you have a timing strobe light, use it to verify that it is not a sloppy timing chain (should not be worn if that is the true mileage).

If the chain is worn, your image of the timing marks on the flywheel will be jumping all around.

[the_admiral]

hi tsal sounds like the timing chain to me as i had the same problem,no real hardship or expence to replace if your fairly apt with the spanners

[tsal]

Thanks for all your replies, Glad I found this forum!! So......., I guess the fun begins:-)
I pulled the rocker covers, and everything seems ok, no metal bits or loose rockers that I can tell. Oil is clean, (however I don't know if its just been changed) The sound is coming from both sides and the front. Also, forgot to mention there is a squealing like wining sound coming from the front cover when started up cold. That sound gos away in a few minuets as it warms up, then the rapping sound at idle starts when fully warmed up. Not sure if there related or not??

I guess my first thing to buy is a good shop manual. Haynes??, or is another better?

Again, thank you for any help/suggestions . I will post findings as I go.

[tsal]

Just curious, Is the tension for the timing chain adjustable on these motors?  

[Bob_Roller]

The chain tension is adjusted by a small piston, that is operated with engine oil pressure, that pushes a rubber coated flat spring onto the timing chain to tension it  .

Also, you need to remove the positive cable from the battery, there are 'hot' terminals under the front cover of the engine, they have power to them regardless of the ignition switch position .

If you touch the cover to one of these, you can get electrical arcing, and possibly damage the charging system diode board .

[montmil]

Awhile back, I had an unhappy noise at the front of the 81's engine. A Harbor Freight-grade stethoscope confirmed the racket was somewhere under the front cover... as in Timing Chain.

Motobins provided me with a complete timing chain replacement "kit". Everything needed in one neat bag.

It's a bit of a chore just getting to the chain but the entire process is doable at home.

Couple tips:  Be sure to position the engine at TDC before removing the old chain. The factory timing mark on the crank sprocket is pretty much invisible. Big dot on the cam sprocket; you can't miss it. A silver Sharpie will mark the two sprockets and help you realign them during chain install.

Stuff bits of paper toweling or clean rag into the multiple openings to the engine's guts. A bear to fish out a master link clip or screw! Extension magnet is a good tool to keep nearby.

My old oil pressure spring, although not rubber covered on my existing or new spring, had collapsed in length as compared to manual's specs and the new spring.

Noise go bye-bye with new chain. Sprockets were not worn beyond limits.  Hope this helps you. I'm betting the cam chain guides and followers are worn through to base metal. The metal/metal contact is the source of the terrible noise.

Monte

[Bob_Roller]

Where abouts, on planet earth (assuming to are form this planet) do you reside ?

[tsal]

Thanks guys. Yep, the more I listen to it, I think there is a Motobins chain kit in my future. I will check the timing this weekend with a strobe as recommended and look for the inconsistency to confirm. I want to do a compression check too. I don't know how long the previous owner has been running it like this, and as a result if there has been other damage done??. Oil looks like it was just changed, so no help there. Will pull the oil filter and dissect it.  Been doing a lot of reading of process of chain replacement. Have never done a job like this before, but I feel brave, and think Ill will give it a shot. Will keep ya posted.

Tony
Webster MA USA

[Rob Valdez 79 R65]

At the worst, if it is the chain, is it is hitting part of the castings on the front of the block (? - I think this is right) and wearing them away.  That could put big pieces of aluminum in your oil pan!

If this is the case, you should plan on pulling the oil pan to clean it out.  If you do, take care tightening the fasteners on reassembly.  These are steel fasteners going into aluminum threads.  It is a common theme on these bikes.  Beware!

In case your timing cover is damaged on the inside, I may have one that is in good condition you can have for shipping.  I'll just need to remove it to check it out.  

[montmil]

...Been doing a lot of reading of process of chain replacement. Have never done a job like this before, but I feel brave, and think Ill will give it a shot. Will keep ya posted.

Tony
Webster MA USA

Get thee to the R65 dot org Photo Gallery. Check out the pics and notes from my timing chain replacement adventure.   Monte

[Rob Valdez 79 R65]

Make sure you have a digital camera and you take pictures of things as you are taking them apart.

[Ed Miller]

How do you guys keep from getting oil all over those cameras?  My problem is it's not MY camera....