Discussion ZXR250 cam chain tensioner...

And yet another chapter of the zxr saga unfolds.

I had ye olde zxr250 running the other day, and an odd sound caught my attention, like a rattle-ish sound that would come and go at different revs (or maybe the exhaust just got louder and drowned the sound out lol), emanating from somewhere within the confides of the motor ( I have no idea >>noob). I have since ceased running it needlessly.

After some googling and much deliberation, I found the most mentioned explanation for this symptom was that darn pesky cam chain tensioner or the chain itself... or both!

Has anyone here had the joy of having one of these replaced? Cost? Any pointers or quick checks I can do?
I read removing/cleaning/reinstalling the tensioner wasn't too bad, but a chain replacement would be best in the hands of a mechanic.

Regards, Ed.

 

Hi Phil, thanks heaps for the info!

I removed the tensioner, gave it a clean and installed it. Gave the bike a turn over and I think it sounded a little worse, a little louder. I was a bit worried about letting it run more than a few seconds where as before it didn't seem that extreme! But I have also heard that the tensioner can be a bit temperamental in the way it likes to sit, requiring several goes to get it right, does that sound right? I'll try it again and post results. But with near 40 thou k's on the clock, and no previous service history it looks like I may be in for a new chain.

I found a chain on ebay for $89 delivered, which doesn't seem too bad.

Also, all the guides I find for chain replacement mention replacing 2 slide things and also refurbishing the tensioner itself, yet I can't seem to find parts specific for the zxr, are there are other bikes that share the same tensioner etc?

I'll pm kiffsta also.

Many thanks!

 

Cheers for the link . I'm reading the manual atm, and finding it a little hard to follow. So the idea is to position the flywheel at 1,4 TDC, then remove old chain, install new, and to engage new chain with the sprockets at the positions indicated in the diagrams?

Tbh, I really don't think I could tackle this one by myself lol

 

Called a few mechanics today, none could give me a quote. Apparently mechanics in Adelaide suck. I was told sourcing parts such as cylinder rocker cover gasket etc is too hard and they would rather steer clear of it! lol. I found a gasket just then. Looks like I'll be doing this one myself! haha

 

Thanks for the support guys! Okay, I've done a heap of reading and watched a bunch of guides on youtube and it's actually starting to make sense ha. I'm waiting for parts in the mail and I'll probably do it as soon as they arrive.

Does anyone have any tips for the install, not specifically for a zxr? Perhaps tips on feeding a new chain through etc? I saw many people covering openings around the camshaft sprockets to prevent chain pins etc falling in, and being extra careful in general.

After researching a lot, and the penny dropping with the manual, it doesn't seem as daunting as before! I'm not letting myself become too overconfident though, I'll be double and triple checking everything as I go! Greyimport, you were definitely right about the abundance of info out there!

Will keep you guys posted when I get around to it.

Again, many thanks for the advice and support.

Ed.

 

Well it looks like I ballsed up on the cam chain, when removing the old chain I somehow managed to get the cam shafts out of alignment. So now I have no idea what to do next...

Any suggestions?? lol

Cheers, Ed.

 

I took off everything required to get to the cylinder head cover. I then removed the cylinder head cover to gain access to the cam chain.
This is where I dropped the ball. I tried to feed on the new chain by attaching it to the old one and turning the motor by hand while feeding the new chain through, and it worked well. Until I realised one of the camshafts wasn't turning so now the cams are out of sync.

What I have done now though is remove the camshaft cap (thing that holds the cams down) then reset the camshafts back so that the EX and IN marks line up as per the manual, all whilst the engine is at TDC 1&4.

I am about to bolt down the cam shaft cap and call it a day. I'm running outta light lol

Next problem is the cam chain riveting, I seem to have broken my riveting tool. The rivet is pushed through with equal amounts on either side of the chain link, just don't know if the riveting I did was effective or not :/

Thanks for your help

 

Thanks for the advice! I'll test the rivet tomorrow and fix it if fails.

Also a few other questions.

There were some o-rings that went on the cylinder head cover. Four of them, 1 for each spark plug hole. Mine looked like they were applied with a tube of gasket goo per ring lol. Is it okay to just peel off all that old gasket goo and apply new stuff?

And also a question with the timing. A diagram in the manual show the EX marks perfectly aligned with the cylinder head. Now, before removing the old chain, I saw that with the crankshaft at TDC 1&4, my EX marks weren't completely perfect... This may seem like a no brainer of a question, but how aligned do they need to be? It's just that I seem to have trouble getting the cams lined up perfectly with the chain on, and I find it hard to estimate where the camshaft marks need to be before clamping down the camshaft cover, which moves the camshafts down.

I think I may take the chain off again, align the camshafts perfectly, clamp them down with the cam plate thing, wrap the new chain around and link it.

*deep breaths*

sorry for all the questions! I'm about start pulling my hair out! haha

 

Will do! I'll get onto it in the morning. Yeah I imagined so for the timing, I'll persevere! Thanks heaps for the advice!
regards, Ed.

 

So I bolted down the cams, timing is all a-okay, but now the bloody rivet is giving me grief lol

Tried improvising with another riveter to no avail, also gave it a few taps with the hammer and when testing it, the rivet always pushes out dang it!

Any more ideas for the riveting? I'll keep trying in the meantime

 

*update*

I finally get the riveting done, bolted everything to spec (had to bloody buy a smaller torque wrench grr), fresh oil + filter, new coolant etc etc...

Fired her up and there were some large, banging noises..

uh oh..

The banging noise was actually me fist pumping the s**t of the fence and throwing chairs around the backyard and yelling in excitement because the zxr fired up perfectly!! She's a goer haha

Thanks everyone for the input, couldn't have done it without you all. Overall I enjoyed working on the bike, a little stressful at times but I loved it. Now i just have to put all the fairings back on and a few more bits and pieces and she'll be done.

Cheers, Ed.