Warm motor > Rattle between 3500 an 5000 RPM

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joeryhaas
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Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Hello zxrworld forum members,

This is my first topic on this forum about a rattle that is occuring in my zxr400.
I recently bought a ZXR400 from 1999, 35000km on the clock (22000 Miles). During the test drive and the ride home everything seemed allright, no weird sounds and no ticking and rattling. Then this week I took the machine for a spin when suddenly a rattle started occuring. The following aspects caught my eye:

- After a 25 minute ride on the highway (70 MPH) a severe rattle started between a surtain rev range.
- The rattle isn't present when the engine is cold.
- The rattle isn't audible at idle, only between 3.5k and 5k RPM's. Also before or after this rev range the rattle isn't noticible.
- Clutch in/out and selected gear isn't changing anything.

After some browsing on the forum the most obvious reason behind the rattling seemed to be either the cam chain or the cam chain tensioner. So I called up the local motorcycle workshop and explained the aspects above. To this he said; "it is not likely the cam chain, this part will just rattle at idle and will go away when some throttle is applied". So what else can it be?

Now I was a little bit confused. So i pulled away the "pulsar cover" (cover where the chain, tensioner, and ignition timing is located) and had a look.
This is where I was confronted with:

Image

The tensioner is fully extended (and the tensioner rod is touching the casing??), this means the cam chain has worn out (is this normal with 20k miles??). Or do I need to look somewhere else that causes the tensioner to be fully extended?
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

The issue is either the chain, or the tensioner blade that's on the left (from the viewpoint of your photo).

Remove the timing plate and see if the metal ring that's at the bottom of the tensioner blade is attached as these can snap and lose tension.

If that's all OK, then remove the tensioner, cams and chain and check it as per the manual, remove the tensioner blade and check it for excessive wear. Replace what needs changing and re-check
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
joeryhaas
Posts: 6
Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Ok thanks Banner!

The tensioner and blade seem to work fine.. Conclusion: cam chain change! Now I will have to decide if I do it myself or let a workshop tackle this for me.

Workshop price to change the chain is very expensive 700-800 euros (600-700 pounds). So maybe best to try it myself, but I’am a little bit anxious about the whole procedure. I have read a amount of topics on changing the chain and it seems like a hefty operation (I only have experience on the basic motorcycle repairs; brakes, carburators, oil etc.). Anything to be warry about while doing this type of thing for the first time? Any special tools I need for the job?
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

Remove tensioner and camshafts
Remove left tensioner blade
Either cut the chain and buy a linked one or it is possible to slide off the chain from the crank sprocket, may require you to grind away a little bit of the aluminium "guard" that runs below the chain.
Reverse, check the timing then check all the valve clearances.
Last edited by banner001 on Tue Nov 10, 2020 8:31 am, edited 1 time in total.
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

I can come help you if you want, but I think you are in the Netherlands?

My car gets over 50mpg and I'm happy to do the driving, but would need my costs paying. I've got 2 weeks off at the end of november
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
joeryhaas
Posts: 6
Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Very kind of you Banner!! But I don’t think it is an effective solution hahaha. Ferry/train to the Netherlands is pretty expensive + with the Covid-19 you will have to self quarantine for 10 days upon arrival..

I’am having a cost estimation made at a local workshop, if this is to expensive I am going to search someone locally (motor-forum.nl :smt002 ). Otherwise the reparation is assigned to me, if this is the case I will take it very slowly and make it a nice little winter project!

I will keep you updated on the repairs and if it fixes the rattling problem.
joeryhaas
Posts: 6
Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Happy to say things are going smoothly! Started this week on the repairs myself and decided to take out the whole engine. As it is my first time changing a camchain I might aswell do it with some room to work on the engine and make it myself easy.

Image

So currently the engine is just pulled out of the frame. Actually easier than I thought. +/- 4 hours of work and no problems whatsoever (thanks to planning it out, reading a lot and working slow and systematically).

But I have a few questions about the maintenance I am executing right now:
- Now the engine is out I was thinking about doing the headgasket as well. The bike has about 22k miles on the clock so maybe it is preferable doing it right now? Any input on this?
- On the forums and in the manual there seems to be existing a shim (0.5mm in a very weird meat fork like shape) on the rear-brake side lowest engine mount. It was not on there when I took the engine out? Is this a problem? Can it be installed with a ‘normal’ ring type 0,5mm shim? Or does the shim shape has a functional purpose?

Image

By the way, I don’t know if it is common on forums like these to update on the repair progress? If it is not ok, unnecessary or unwanted please do say it! First time ‘active’ on a motorcycle oriented forum so don’t exactly know what the standards are :).
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

Yes there e is a "build threads" section of the forum, always good to post progress in there.

Yes absolutely change the head gasket (very cheap part), you would also be wise to check and adjust the valve clearances once all the head work is done. You can also check for any debris or rusting in the water jacket.

I would also remove the oil pan, remove any sludge from the bottom and clean off the internal oil screen.

I would also pull out the clutch, checking the friction thicknesses, the steels for blueing or warp, and the inner and outer clutch baskets for damage/wear.

Its also a good time to replace your thermostat and any gaskets along the way.

Once you remove the cylinder head check the liners for and damage or scoring.

This way you have replaced everything that's not pistons/rings/shell bearings or gearbox.

If you have a bit more time and resources I would say perform a compression test before you do any work, then lap all of your valves to clean up the sealing faces, use new stem seals and then retest the compression afterwards, this will show you how well the rings are sealing as that will be the only source of compression loss now.


And as for that shim, I've never seen it on a bike, can't say that it's a massive loss if its not in there?
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
joeryhaas
Posts: 6
Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Problem number one!! :smt010

Ok, so I ordered in a lot of parts to continue the project. Everything seemed alright until I wanted to order a headgaket.

For the zxr400 there are 2 typer of headgaskets:
- H2 with part number 110041182
- L models (i guess) with part number 110041321

The L model gasket isn’t available anywhere.. The H2 gasket is available everywhere. So some wisdom is asked for :)

What is the difference between the two?
- Do both fit my 1999 zxr?
- What is the advantage of the newer gasket? Or is there even a advantage?
- Any advise or tips
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
joeryhaas
Posts: 6
Joined: Tue Oct 20, 2020 11:14 am
My Bike: ZXR400 L9

Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by joeryhaas »

Ok, Christmas holidays have arrived. So I pulled of the rockercover and set the crank at TDC (TF mark on the timing plate). The cranks are pointing outwards, but do not exactly line up with the top of the cilinder head?

Any thought? Is this right or has the chain skipped a tooth?

Image

Image

Image
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banner001
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Re: Warm motor > Rattle between 3500 an 5000 RPM

Post by banner001 »

I can't quite see the marks as the picture quality is a bit low, but it's likely to be because your chain has stretched too much.

When you change the chain they will line up properly
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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