K75 T with Timing Chain Rattle - pre diagnoses?

[bluebossa]

Hey again folks...

Yesterday I bought a fairly rare K75 T - at least in the UK, not many were sold, the UK weather I think putting most people towards the RTs
Anyway its a Red, 1994 T with ABS... now while I'm not a fan of ABS on K Bikes, too much complexity and added weight, I do like a Naked K Bike... I'm especially fond of the K75 as you might know, this is my 5th now.

While I'm waiting for it to be couriered up to me - could you help with what I might go after...

Here's the description from the Seller as to front end timing noise...

"Some weeks ago, the engine developed a loud rattle at low revs. I was concerned enough to pay a mechanic to check the bike over. He advised that there was a problem with the cam chain and said that it would cost £700 to repair. The bike starts well. It may or may not be rideable in its present state. I am disinclined to risk riding it."

Now I've got a spare Engine - taken from my 50k K75 C on the floor and I'm thinking

- timing cover off - on both new bike and donor Engine
- compare chains and chain tensioners
- replace everything guide wise and spring wise from the 50k Engine

Happy to post pics, videos when it arrives - maybe later this week.. but I've never done a timing chain so any tips, what to look for, anything else the noise could be coming from?
Meanwhile here's a pic of the 48k K75 T - planning to save this one rather than strip for parts... as I've also started stripping K75s - took an RT apart last week and started an eBay shop called "Flyingbrickparts" in the UK

Thanks in advance - would appreciate your wisdom on what to look for first?

[Laitch]

It would be helpful for you to make a video containing the noise with all its permutations during idling and moderate revving, post the video on YouTube as public, and then post the link here. In my opinion, it's too early to focus on the timing assembly although it's a possibility. When somebody indicates a loud rattle, the alternator rubber dampers are my first consideration and relatively easy to rule out. Faulty fuel injectors would be next.

[bluebossa]

Interesting, thanks Laitch, I love the fact that you don't just jump and assume, a fault of mine... I'll happily do that on arrival and post on YouTube..

Alternator Dampers and Injectors - Intrigued...

The Timing assembly was the guess from a Mechanic the seller Employed... so I'm with you...

[TriSpark]

The cam chain rattle diagnosis sounds like a guess from a mechanic who hasn't much experience of K bikes, and that's not unusual as they don't see them on the work bench as often as they used to. 48K miles.....my K75 has 120K and no trace of any cam chain noise at all. When I lived in London I had a plain K100 with 80K on it, and no cam chain noise on that either.

One thing I've learned here is to always follow Laitch's advice before tearing into the engine. Let us know how you get on.

[bluebossa]

The cam chain rattle diagnosis sounds like a guess from a mechanic who hasn't much experience of K bikes, and that's not unusual as they don't see them on the work bench as often as they used to. 48K miles.....my K75 has 120K and no trace of any cam chain noise at all. When I lived in London I had a plain K100 with 80K on it, and no cam chain noise on that either.

One thing I've learned here is to always follow Laitch's advice before tearing into the engine. Let us know how you get on.

Laitch is a legend, I always listen to him, hence my post - Laitch has saved me hours of faffing around over the years, thanks TriSpark... video on arrival with good sound.
Agree re Mechanic though it must be some noise from somewhere... does seem low mileage though for Cam chain as you say!

[bluebossa]

OK @Laitch as requested... it arrived on my drive this morning UK time...

Its got the high RT bars - but its a T - Naked... nice old thing, one of the later ones.... 1994 with ABS (which I hate)

Here's that Video and I do think your remote diagnoses may well be spot on - so I 'll dive in and let you know...
Certainly not going to open the front yet... !

[bluebossa]

Yep... any tips on how to remove the drive on the end of the alternator, needs that and new monkey nuts...

THANK YOU LAITCH - AGAIN SAVING ME Hours!

I've got a spare but the drive is the same - replacements en route...

[Laitch]

That's a useful video. I recommend anybody with a mysterious noise post something like that for group diagnosis.

I used a strap wrench to anchor that cup for removal. Use Liquid Wrench, Kroll or PB Blaster on the nut and screw. After spraying, tap the nut and screw joint a few times—without deforming either—then let them sit for fifteen minutes or so before disassembly. This is my usual procedure on fasteners that likely haven't been touched for years. Regardless of what you choose to do, they should release each other without putting you through a dying strain on the end of the wrench. If they do, regroup, heat up the fasteners with a heat gun, apply the penetrant until you're smoked out of the room, have a coffee then try again.

It looks like you've got things under control. Wipe the dampers with silicone grease so they'll stick into position. Align the arrow so the paddles will index correctly into the damper joint spaces.

[bluebossa]

That's a useful video. I recommend anybody with a mysterious noise post something like that for group diagnosis.

I used a strap wrench to anchor that cup for removal. Use Liquid Wrench, Kroll or PB Blaster on the nut and screw. After spraying, tap the nut and screw joint a few times—without deforming either—then let them sit for fifteen minutes or so before disassembly. This is my usual procedure on fasteners that likely haven't been touched for years. Regardless of what you choose to do, they should release each other without putting you through a dying strain on the end of the wrench. If they do, regroup, heat up the fasteners with a heat gun, apply the penetrant until you're smoked out of the room, have a coffee then try again.

It looks like you've got things under control. Wipe the dampers with silicone grease so they'll stick into position. Align the arrow so the paddles will index correctly into the damper joint spaces.

Thanks Laitch - Sorted, big lever and it relented... 22mm socket

Its a lovely Bike - weird that Naked T with RT bars, but maybe they switched to that for the later models... My C bars are lower...