Low RPM chain type rattle

I have an 87 ZN 1300 with approximately 57,000 mi on it. I have put about 500 of those miles off the bike.  I've looked through both these forums and the forums on the American Voyager Association and I haven't found exactly my problem. The issue I am having is that I am hearing chain type rattling noise at low RPMs below 1300 RPMs. I know that these bikes do need periodic valve adjustment and I could be wrong on this but I should be having hard starting issuesI have an 87 ZN 1300 with approximately 57,000 mi on it. I have put about 500 of those miles on the bike.  I've looked through both these forms and the forms on the American Voyager Association and I haven't found exactly my problem. The issue I am having is that I am hearing chain type rattling noise at low RPMs below 1300 RPMs.   I know that these bikes do need periodic valve adjustment and I could be wrong on this, but I should be having hard starting issues with this bike if the valves are out of spec, correct? This bike fires up right away. I pulled it out of storage 2 days ago and hit the start button and it fired up within half of a rotation. It always fires within two rotatio

First, Welcome to the site. Although we don't typically work with the Voyagers as much as the American Voyager site, it won't hurt to bounce things around here as well. We'll try to help if we can.

Your 87 Voyager has what I would call a "hybrid" Chain tensioner compared to the KZ1300 engines. The KZ's have a tensioner that has a spring to advance the tensioner where the ZN1300 has a hydraullic plunger that advances the tensioner to take up the slack in the chain. I'm somewhat familiar with the hydraullic system since I had it in my Porsche 928. That being said, the ZN1300 has a spring on the tensioning rod and I "believe" that it's there to hold the tensioner rod one way stop up against the plunger. this one way stop is there to stop the plunger from collapsing under deacceleration.
4 things to check here in my opinion.
1.) the tensioning rods tend to wear and will show signs of what I would call chattering. Looks like grooves with indentations. If so, the check balls in that one way stop can't lock down on the tensioning rod.

2.) The other thing that may be contributing to the problem might be low oil pressure at idle and if the tensioning rod has chatter marks and the oil pressure is low at idle, that would answer the question.
3.) The tensioner arm has a nylon sprocket which can wear down and or crack and split off the bearing and it usually happens around the 50000 mile mark if the tensioner is not carefully checked periodically. www.liska.com has a steel replacement and quite a few of us have opted to replace the nylon one with the Liska sprocket.
4) There's also a neoprene tensioning roller on the tensioning arm and quite a few members here have found that neoprene roller cracked, broken and or disintegrated. If so, you would find rubber bits in the crankcase oil.
Both the neoprene roller and the nylon gear can be seen by taking the cam cover off and looking down the back side of the cavity in the head. It's not easy to see both but it can be done and I would highly recommend that you do this if nothing else.

A few of us have done engine overhauls and when checking the oil pressure relief valve, have found it stuck slightly open and not fully closed and this will drop the oil pressure at idle and yet show fine oil pressure above 2000 rpm .

I'll leave these thoughts with you to ponder. Would appreciate it if you could follow up and let us know what you figure out.

KB

KB - great response. Thanks for taking time.
 

 I am aware of the issues with wearing that the original tensioners can have . One of the first things I did with the bike was check and see if the tensioner was changed for one of the ratchet style one and it was.

I will have buy an oil pressure gauge and check the pressure.
I will also need to find my endoscope camera and dohet a better look inside.

The pictures are reference so you know what type of  tensioner I'm speaking of.
I will keep you all updated as I go. This bike is one of a couple projects I have going on, so It may be slow updates.
Thank you for the information. It all helps.

Original style



Current style installed
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Ok. More information provided. Good, thank you.
You're working with a ZX11 tensioner which is one of the tried and tested mods done on the KZ's.
Some have found the spring tension on the ZX11 tensioner to be much higher than the KZ tensioner. A few have cut 10mm off of the spring to lower the tension. I have no experience with this tensioner or mod and maybe another member with ZX11 tensioner experience can chime in here please. I have wondered if cutting the spring had ill effect when at maximum stroke.
Be aware that the nylon sprockets can and have worn down keeping the original appearance yet the minor diameter of the sprocket was found to be greatly reduced. Usually we find the teeth all chewed off. Somewhere on the site I posted pics of a used but within tolerance nylon sprocket beside a new nylon sprocket and then there are other pics of the Liska sprocket.
the noise you describe has been heard many times before and reported. Some paying attention caught it in time. Some paid the price and jumped cam timing which then bent valves. Here's hoping that you've caught it in time.
Just as a note - being a new member, the site requires 2 posts that can only be seen by an Administrator first and approved by us to confirm that you are a legitimate person and not a business or "other" looking to sell on this site. Now that you've met the requirements, your post will be posted immediately and not requiring an Admin to approve.
Enjoy the site. We are here to help and share experiences.
Cheers,
KB

Okay good. I will take into consideration the wear mentioned. I can also pull apart the tensioner to see if I can find evidence of a cut spring. It's an easy part to get off as I've done it once already. As stated before i will get a better look with an endoscope camera when I get time. It may be a few weeks though this is a side project. My primary bike is a 2000 zg1200 (Voyager Xii). I have basically parked the 1300 the last couple years for fear that I may jump timing and destroy the engine.The goal is to take this bike to the AVA rally next year in Tennessee.