Rattle at idle

[kettle738]

Hi all, my RE5M which has 40,000m and runs beautifully, has a loud metallic rattle when idling.

The sound appears to be coming from behind the clutch actuator / gearbox sprocket cover, and disappears as soon as the slightest tension is placed on the clutch lever.

Just taking up the free play makes the rattle disappear, but it clatters away as soon as the clutch is released.

Has anyone got any ideas or suggestions as to what might be causing this?

The motor is otherwise very good, the only obvious evidence of it's mileage is the initial cloud of smoke on startup if it has been left standing for a while; that clears after a couple of minutes and then it runs fine.

Mick..............kettle738

[steveuk]

try removing the sprocket cover and then starting the bike if the noise has gone with the sprocket cover off then the problem is with the actuator mechanism

steve

[kettle738]

Thank you, that makes perfect sense, I will try that; I did wonder if something was causing the clutch pushrod to chatter along it's length, but I couldn't think of any reason it could or would do that, but removing the cover would answer that soon enough.

thanks again.............Mick...........kettle738

[maleric]

My first RE5 has ALWAYS done this - for over 20,000 miles. I don't know why. It never got worse, it has always concerned me because I never knew if it would fail "bad" all at once and leave me stranded. But in my younger years, I had no fear and kept riding - even long distances such as 500-600 mile weekend trips.

Removal of the clutch cover is something that I would not attempt by myself - in the past my mechanic friend did this for me. But that is me, I'm not the best at taking things apart and putting them back together. If you have the tools, the time, the patience, the general experience, the service manual, then you could be OK. (specifically, the hard part is the fact that you are breaking water seals, oil seals, and affecting the ignition system, too because the distributor comes off with it - so if you don't reassemble correctly, you could have leaks and need to remove it again).

But I did not answer your question: what causes it? I suspected it was the clutch itself, but wait for other members to post a response ( or for Jess to post) before you do anything. The other thing I suspected was the primary chain and/or its tensioner. But that does not really narrow it down...

Eric

[maleric]

Sorry - on the last post I thought the noise was coming from the other side of the engine!

[kettle738]

Thank you for the input, all suggestions are much appreciated, that is how it will eventually be traced. I realise the noise which really does sound like it is directly behind the clutch actuator cover could easily be generated elsewhere and transmitted.

It is very interesting to learn your RE5 is the same, that suggests it may be a fairly common issue that someone has already solved.

I agree with your comments about removing the large transmission cover; having done it on my last RE5 it's not a job I would rush into doing again unless it was absolutely necessary.

I found the most awkward thing was preventing the points shaft from rotating while I was trying to line everything up to re fit the cover, and that was solved by drilling a hole in a small piece of alloy bar, just long enough to bridge the points housing and screwing that to the end of the points shaft using the screw that's already there, and that temporarily locked the shaft in position to allow accurate fitment.

But yes, it's a pain.......Mick.........kettle738

[kettle738]

I took the plunge today and pulled off the large clutch cover in an effort to discover the source of this seemingly clutch related clattering. The first thing that was instantly apparent was a loose steel band on the clutch housing, which is what Jess said it would be on another thread.

I have a spare clutch from a 16,000km bike that cracked it's rotor housing and the band on that one is tight. Tomorrow I'll get the pair of them tack welded and once it's all up and running again I'll post the result......fingers crossed it cures it.

Mick...............kettle738

[steve w]

Hi mick the rattle can be caused by wear on the thrust washer, between the clutch basket and the clutch centre as they wear it it gives you more end float ,and when you put a bit of tension on the clutch lever it stops the rattle.could be cured by replacing clutch basket and thrust washer. but it wont cause you any problems, as long as you can put up with the rattle.

steve uk

[kettle738]

Thanks Steve, yes I was looking for that as well as I thought it highly likely, however I couldn't feel any discernable end float on the clutch when it was bolted up.

The other thing that now makes me think it may be the steel band is, the bike never used to make this noise, it just started, so a steel band becoming loose would explain that, whereas unless I've missed something I guess end float would be something the bike was built with?

Thanks for the input, it's always good to have multiple opinions as there is never a guarantee that any 'fix' will work.

Mick..............kettle738

[kettle738]

Hi Steve, it turns out you were right about the thrust washers but it's a bit odd. I found my primary chain was totally knackered and as I have a decent one from a low miles engine, off came the complete primary drive.

I wasn't expecting what I saw next, the inner of the two clutch thrust washers has been badly chewed up by contact with the starter clutch boss, if I wasn't such a computer plank I would post some photos of the carnage.

The good news for me is that I have near perfect examples of all the affected parts from my dead engine.

The second surprise was that the primary chain, which was flapping about with an inch of free play on the un tensioned side and felt totally shot was still within service limits if I'm measuring it correctly.I guess with 40,000m up it's fair enough though.

The spare chain was a full millimeter or more shorter laid side by side and when fitted along with the sprockets, tensioner and starter clutch from the low miles engine the difference was incredible, the slack has disappeared and it now feels perfect.

Hopefully the replacement clutch complete with starter drive and thrust washers will do the job, I'd like to know why it happened as the push piece turns freely, the small needle bearing is perfect and there is sufficient free play. The clutch itself has always behaved perfectly, no issues at all.

The starter clutch centre boss was totally chewed, and yet the starter never gave the slightest trouble, never slipped once.......they're tough. Once it's back together, tomorrow hopefully I'll let you know if it's quiet, I'm hoping for a real improvement given the state of the parts that have been replaced.

Mick...............kettle738

[plipton]

Mick,

Mine rattles too but I haven't had a chance to look into it yet (too many other things to sort first ), but email me the pix and I'll post them up for you (rick at plipton dot com).

Cheers
Rick

[kettle738]

Here are some pics of my RE5 and it's recent rattling clutch problems, thanks to Rick for uploading the photos, I think I realise what is needed to do that now, hopefully I've pasted them correctly.

The first shot, taken a couple of weeks ago shows that despite a few miles she still looks the part....all original Suzuki red paint etc.

i1218.photobucket.com/albums/dd411/mrplipton/kettle738/kettle738-04.jpg

The second is the starter clutch gear and corresponding thrust washer, the damage is pretty severe, and yet the only symptom was the clattering at idle, beyond that, no ill effects at all, the starter clutch continued to function perfectly.



Picture three shows the primary chain I removed which is possibly the original 40,000m chain. I laid this chain and it's replacement alongside in this simple wear test and the replacement was markedly less curved, compared lengthwise the old chain was more than a millimeter longer, which doesn't sound much, but this is a very short length of chain.

i1218.photobucket.com/albums/dd411/mrplipton/kettle738/kettle738-02.jpg

Although it was impossible to assess by eye if the sprockets were worn when compared to the spares from my low miles engine, I could feel sharpness with my fingers which was not present on the lower mileage parts, so I swapped everything, both sprockets, chain, tensioner, starter clutch assembly and clutch basket. The old chain tensioner was hard and had lost a couple of small chips from the wheel, where the replacement was still soft and unmarked. The old chain when crudely measured was amazingly still within service limits, I don't like to think how knackered they have to get to be considered unserviceable.

When re assmbled (pic 4) the difference as I said was incredible, the previous chain had been hanging like bingo wings on the un tensioned side where the replacement is just perfect, I was shocked at how much difference a seemingly small amount of wear could make.

i1218.photobucket.com/albums/dd411/mrplipton/kettle738/kettle738-03.jpg

Hopefully this may help someone else with the same clattering clutch problem.

Mick.............kettle738

[steve w]

hi mick pleased you sorted it out .

steve

[HGH 770N]

Hi Mick
Glad you sorted your problems out. Seems alot bigger than you antisipated .
was this bike always a rattler, or could it have been due to lack of service in its earlier life ?
or are we looking at a design problem using GT 750 parts

Rog

[gerryggg]

From what you say and the pictures of the chain, I suspect your rattle was the primary chain. I don't think the starter clutch was the noise. The early RE5s were very prone to starter cluch failure though. I would look very carefully at the rollers to make sure they're still round and the ramp to make sure there are no waves in it. If the clutch fails you'll get to experience the joys of trying to kick start it (been there did that). If it seizes it could seriously damage the crank.