Kwikasfuki GPZ 550, loud sounds, hard to start, engine trouble
 

Hi,
First off I'm new to this forum and would like to say Hi :]
Second I'm a newby at motorcycles and fixing engines and such.

Well the problem I'm experiencing just now with my GPZ 550, 82' is that it is making a very loud rattling noise from the left side of the engine. Described in greater detail below.

A week ago it was starting with no problem ready to go in a second. After experiencing some bad weather this week it has gotten progressively worse.
Upon start up, you could initially start it with the starter, now you have to jump start.

Once it starts it sounds like a bobber almost, with a loud noise coming from the left side of the engine (I couldn't exactly find where from, you could hear it if you moved from front to back all the way along even under the carbs), which I fear might be one of the pistons. Accompanying the sound you hear a puffing sound as if there is air escaping the combustion chamber. In addition to that when you touch the unexposed spark plug wire on the left side of the bike it shocks you a bit. Also the sound gets less loud but more frequent the more throttle you give it. It remains through all the gears and through the range of RPM. When you leave the throttle alone it dies quite quickly, and again you have to jump start.

Now I thought that would be the cam chain tension-er, but I'm not sure, some how I don't think it's that.

Initially I thought it was just battery problems due to the weather, as I've always had a very slight rattle and didn't pay attention to it as another person with the same bike had the same sound.

I really need your help folk, I would also make a video but I'm not sure I really want to do that, because it might just screw the engine over even more. :confused:

Any help would be appreciated :cool:
Thanks :)

That's a video of the week before the bike started acting up.
Mar 13, 2013 4:24 AM | Facebook

A good plug wire will not shock you. I would check there first.
Do you have a manual on how to check things out?

Welcome to KF

I have a service manual supplement for my bike, it's not proven to be very helpful so far. I've been trying to find the book but no luck.

I'll check the plugs once it stops snowing, as I don't have a garage and I don't know anyone that does I'll have to do the repairs outside. :/
Thanks for the suggestion. :]

Straight off, the ignition leads and the battery. If you're miss firing on one or more cylinders it will sound like a busted tractor. The crank in those drives the gearbox via a multi row primary chain that sounds terrible when the motor is badly out of balance as it's being slapped around. If you got a shock off the lead, replace them. Don't use any of that silicone rubbish, either. These are wire cored leads.
As for the battery, cold weather can be the final straw for an old battery. Check the connections and electrolyte level (top up with distilled water ONLY. Never I repeat NEVER use tap or rain water) and if possible give it a couple of hours on a charger. If that doesn't sort it, get a new battery.

I went to one of the motorcycle shops in Dundee and they said to check the spark plugs, ignition coil, and just generally the electronics. Told me to run it for a min and check which of the exhausts are cold and which are hot, if two of them as in 1&4 or 2&3 are cold it means it's a problem with the ignition. So I'll do that as soon as I have a chance to ( stops raining in bloody scotland ) but yea I feel pretty confident it's not the engine causing this :] after the talk. However he said " That bike is ancient, I'll give you advise but I'm not touching such an old bike. "
Anyways it's not the battery as I swapped it with my scooters battery and it starts straight away. It's got plenty of life in it.

That was a good shout out Dark Angel, the mechanic said pretty much the same thing. As it runs what it actually does is drag one or more cylinders and is causing that tractor like noise and hence it dies quickly after the throttle is released.

Thank you for the suggestion :]

I used to ride a Z550G1 (had two in fact). I still hold a soft spot for them. They have almost exactly the same engine as yours and use the same workshop manual. I wish I'd never sold my last one, especially when and how I did.

Found out what was wrong with it.

1st - If you have a similar problem, as most members suggested check the wiring and spark plugs.
My problem was that salt built up on the tops of the spark plugs and they weren't making a good connection. So just sand down the salt or scrub it off.

That got the engine running...

2nd - That really loud noise you could hear, was not only because the pistons were being dragged around but because the cylinder head gasket had blown. So air and oil was escaping.

Which I am yet to replace as I'm quite busy with exams right now.

Hope this helps someone else too :]
I might put on a video on how to replace the head gasket if I can be bothered.

You located that issue visually? The air escaping was mentioned in your original post but not the oil.

Congrats on the diagnosis. You may as well get your tools ready to check and/or adjust the valves while you tear things apart.

Well I noticed the oil after I went in for a closer look, when the engine was cold. Now I've tore down the upper body of the engine, up until the head gasket. It looks like it's blown and it's where you could hear the sound coming from.
One thing I noticed though was that the pistons looked very bad, as if they had a bit of rust on them and an accumulation of particles on top of them. The bores where the pistons go look nice and shiny but the pistons themselves are concerning. It might be because of rich fuel mixture or just bad quality fuel.
I've taken pictures but I haven't gotten around to ask the mechanic, I talk with, what he thinks of this. So I'm gonna go in tomorrow and see what he says of it.
I might need to change the pistons. I'll take a look at them and see if they are loose and all. I could just try and clean them up a bit if they aren't loose.

Anyways I'll upload the pics tomorrow so you guys can have a look as well :]

*Edit*

The photos below \/

http://imgbox.com/gallery/edit/FGjXg...yKai29Wxf0JXwO

Clean up the pistons and cyl with no 1 diesel and a bronze or nylon brush to take the carbon off of the piston tops. Straight edge the cyl deck and head. Feel for an edge at the top of the cylinder for wear. From the pictures, it does not look that bad.

like you mentioned, after you check the pistons and rods for clearance or excess wear/movement, you will know more.

Checked for wear on the pistons and the block, it feels like it's in really good condition. There is no movement ( rocking ) from side to side from the pistons and you can feel a nice sharp edge on the top of the cylinder. I've given them a good clean as well. All I need to do now is find the right gaskets for the cylinder head and the head gasket. Gonna look for something with relatively good quality and moderate price. :]

I'll upload more pics when I have the chance. :]

That sharp edge is called a "ridge" and just confirms there is wear in the bores, which is completely normal for an engine that age. If you have the head off just have a look at the bores and check for scoring. That's vertical lines, especially ones you can feel with your fingernail. Those are bad. If everything is in reasonable order you shouldn't have those but it's worth checking if you have the opportunity.

new head gasket, re torque, valve adjust and cct adjust if not manual adjuster.. Another 100k mile engine or so it seems.

Update:

Got everything assembled and running ! :]
This web-site helped A LOT ! with the timing of the rocker shaft:
GPZ550 Camshaft Info

Here are some pics...
imgbox - fast, simple image host

Checked for scoring marks and such, I couldn't notice any. CCT adjusted... what do you mean by re-torque ?

Problem occurred...
While driving I could hear a nasty clacking noise coming from one of the cylinders, I think. I can't locate which one. I'll upload a video of it.

If the same noise is happening while at idle, get your long handled screw driver or stethoscope to locate that noise. It could be that the CCT is not working properly. The teeth tend to wear down but that is noticable visually when you inspect it prior to re-install.

I tried using the the screw driver to locate the noise, I checked for consistency in frequency and sound over the top, middle and bottom of all the cylinders. The only slight, and I mean slight difference was with cylinder 3.


I was searching for engine noises in youtube, looking for something similar to mine, and I found this. Just for comparison with my video.


Also when I was installing the chain on the rockers it didn't seem like it had any slack or movement around the rockers after installing the cam chain tensioner to tighten it. Also made sure when installing the chain to count the pins and get the timing right. So I am certain everything timing wise is good.

Do you think I should disassemble the engine again ?

I fear the worst. It might be the crankshaft making that noise. Maybe particles got in the oil and are rubbing against the bearings wearing them down. If the sound I'm hearing is a loose connection rod to the crankshaft it might be a serious job. Or it might be as simple as tightening a bolt, I am worried.

Am I understanding this right.. CCT is "Cam Chain Tensioner" right ?

Yes, CCT= Cam Chain Tensioner


I would definitely check your timing and cam placement again.

Thanks for the link. Got me looking into my '83 manual which does not show the hex bolt holes for the exhaust but it makes me second guess my fsm pic/description on the intake and exhaust hole location. But at least you noted the cam bolt locations on removal.

edit: Is this a US model using the clean air system?

Can you specify what you mean by US clean air system :?

Some models have an air intake into the exhaust port and/or collect fuel vapour into a charcoal canister to help the engine meet air pollution restrictions. When everything is fine you don't notice it, but when things aren't working so well it can be a pain and cause a lot of trouble.

I have no idea to be honest, any way of checking for it :?

It will be in your manual. Normally has two vacuum lines to the #1 and #4 carb boots going to a large valve sitting ahead of the valve covers that then has maybe a 20mm diameter rubber hose split off to the valve covers with one large hose going back to the air box. It basically uses engine pressure/vacuum to send oil vapor back into the airbox to be re-burnt. (the jist of it)

Not saying that this is an issue with your ride, was just curious.

Nah.. my bike isn't as fancy as that :D All I got is a hose going from the 2nd carb to the fuel tank to get fuel pumping using the engines compression and vacuum.

As for the rockers I am pretty sure I got them right, I'll take you through the steps:
1. Put the rockers in the right orientation.
2. Adjust the 1st rocker using the EX line, to line up with the engine block pointing towards the exhaust pipes.
3. Adjust the 2nd rocker using the pin count method, in my case the Z/5 line goes in between 43/44 pin. The Z/5 line should also line up with the engine block pointing towards the carbs though.
4. Install the rockers completely by bolting them down.
5. Install the CCT ( cam chain tensioner ) and check for slack in the chain. Check the alignment of the rockers again relative to the engine block.

Let me know if you notice anything I shouldn't be doing.
I'm not saying that I couldn't have gotten something wrong there, but the bike has never started up so quickly.

Edit*
I think I figured what might be causing the racket. I'll check tomorrow and let you guys know.

Nah still no luck...

I found a small washer in the Cam chamber which was bent. So yea I admit it I made a crucial, stupid mistake I forgot to inspect for any dirt and debrie before I closed it up. Thankfully no damage to anything, this time I took my time to do a thorough inspection. Also while I was down there I checked the timing again. The timing advancer was set to line T when the 1st cylinder is at TDC fire stroke, and everything else as described above. Checked if the bolts on the rockers are properly torqued... everything seems good.. why is it making that racket.

I closed everything up again and ran it. The sound still persists, opened it again checked again, nothing.... I am baffled. What could be causing this :? I believe it is coming from the rockers chamber, but I fail to find any clue to what it might be. ( of course I removed the washer after I found it and checked for any other things not in their place )

This engine is a shim under bucket configuration. A hard starting engine, timing or other engine clanks really makes me want to check the valve adjustment and timing. Let me look for the "T" on the advancer when cylinders #1 and #4 are at TDC in my manual.

edit: The mark is between the T and the C on the advancer from the looks in my manual.

I'll take a look when the sun comes up :]

I think I found what the problem is. One of the valve buckets in the cam chamber is a bit raised compared to the others, which indicates probably what I feared a bent valve due to incorrect installation of the camshafts the first time around. Oh well you learn from your mistakes. Maybe a costly one but..what are you gonna do :/

Oh sorry for the late update ^^, but yeah that was the problem it was that bucket that was causing the racket. The shim under the bucket had come out of it's place and when ever the rockers where doing their job the bucket was clanking against the shim. So am it was really an easy fix ^^ I just had to push on the spring system that holds the valves and simply put the shim back in it's place. However the reason why it came out in the first place was because I was revving the engine too much ^^ I get excited when I'm happy and I tend to show it trough my driving :D . So yeah... thanks for the help folks I really appreciate it :]