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Posted (edited)

So a lot of you will know I bought a 15 year old ninja a few months back for real cheap.


The plan was to use it over the winter in the salt and snow, to keep the CBR off the white stuff, then polish 'er up and turn her into a track bike for a bit of summer fun with 0 fear of trashing the thing, because lets face it, its a bag of sh*t to start with.


Anyway, amongst its many flaws, it doesn't run right. Give it the beans and get the revs high and its alright, but keep them low, especially around town and it will stutter.


So, I decided to rip the thing apart, with no haynes manual and little knowledge of that anything really does, I mean, I know the basics of a combustion engine but I dont really know what I'm looking at. After replacing the air filter (and spark plugs) I realised there was an oily substance around the air filter. I wasn't 100% sure as it may have been a bit of fuel or just grime thats built up over the past 15 years.


After putting it back together and realising it still runs like a bag of nails, I took it all apart again, took off the carbs and had a look down what I can only presume is the inlet to the combustion chamber (although I'm not 100% sure), and whilst the bike is on its side stand, you can see a liquid down one of the ports, coming up over the valve


024286631926b0fab5130f7c5ec20cbb9ada897e66feb460fa47d94009c1045c22958d1f.jpg

356899499f42a22279b976c6500e62b29726391ba75654ef7e73bd7ec578608901392fa1.jpg


I presume its oil, but there is no significant oil loss and no smoke coming from the exhaust once its warmed up


Any idea of

A) what it is

B) will it be hard to fix (with a haynes)

C) can I still ride it like that over the winter without doing too much harm to it, until the salt comes off the roads and I can fix the thing?

Edited by mealexme
Posted

To start simple (probably too simple, but what the hell)...

What's the oil level like / what was it like when you got it? As far as I'm aware, overfilling it horribly can lead to oil being forced into the airbox (via the crankcase breather) and past the valve seals. Does it smell at all like it's burning oil? That would certainly help identify if you've got something coming from behind the valves that shouldn't be.


Disclaimer: RantMachine don't know shit

Posted
To start simple (probably too simple, but what the hell)...

What's the oil level like / what was it like when you got it? As far as I'm aware, overfilling it horribly can lead to oil being forced into the airbox (via the crankcase breather) and past the valve seals. Does it smell like it's burning oil or do you get a blue tinted smoke from the exhaust? That would certainly help identify if you've got something coming from behind the valves that shouldn't be.


Disclaimer: RantMachine don't know shit

did an oil change to the correct amount. Same issue as before. No smoke once its warmed up. Not that I've noticed anyway. I have checked in the past though



Also, the liquid only seems to be in the one port, there is none in any other port and no residue in any other carb but the one on the far left

Posted

Assuming you've done a reasonable bit of riding since servicing it, perhaps worth checking the filter and airbox once again to see if you have fresh crap in there? At least then you'd know if that is connected to the problem or if it was just the product of years of mistreatment. Don't suppose you recall how the old plugs looked when you changed them? (Better still, if you're as bad as me - do you still have them kicking around somewhere? :oops: ) If it's just one cylinder that's looking dodgy then that should have given you an inkling as to whether it really does have a problem compared to the other three. Could even see how the new plugs are looking if you don't mind the hassle of taking them back out again :lol: Certainly has the potential to be a nice and easy way of working out why it's running shoddy, even if it doesn't answer the liquid issue in the left cylinder (assuming that's oil, I would think it can only be the valve seals that are buggered?). You even have the luxury of multiple cylinders so you have "healthy" plugs to compare it with, you lucky dog :lol:


Disclaimer: Seriously, RantMachine is the WORST person to listen to about this sort of thing. Except maybe Petrolhead, but it's a bit late for that.

Posted

Mine was running quite bad too. I fixed mine with redex and pretending it was fine until it fixed itself


I know even less than Rant, do not listen to me

Posted
Better still, if you're as bad as me - do you still have them kicking around somewhere?

 

I still have a broken clutch lever from a bike I sold 2 years ago... :oops:


Filter is a bit oily. Not done many miles since the service to be honest, it ran like crap so its been sitting on the drive looking sorry for itself for the past month or two whilst I use the CBR


Its just the left cylinder that looks to be the oily one and any different from the others.


old spark plugs

(in order from left to right)


173881778ed73b26e5d2e337146138df30c0d37010ffceb96a153e2335354ad407ad303d.jpg

30044865c51e96f1d76c9981dc23d07112a9a4292fb236ccae312bd57343b8ec5a8975e1.jpg


new spark plugs


389052340057057b94dedcd8c61e59a57e0f2f1ccf33a7395729c0cbbf3657636ed7439b.jpg

299833179bae3f4b77a85e5a78a7d071d1606cfe43634296f20881ce73498c2f438e6539.jpg

Posted

Can't make them out well enough to comment, but give this a glance then look at all of the old four up close and see if you can spot anything of note:

http://www.aa1car.com/library/reading_spark_plugs.jpg


Also,

I still have a broken clutch lever from a bike I sold 2 years ago... :oops:
I like your style :thumb:
Posted

ooh I think I know this one, the two on the left with white residue show it's running lean but the other two look ok.

If the carbs are unbalanced even I know that will cause it to run bad (used to have a twin carb car that was never balanced and was a pig when cold).


I found trying to balance them (even with a gizmo) a pain in the behind. Hours later still wasn't spot on. Knew a guy who could do it by ear in two minutes!

Posted

Valve stem oil seals need replacing of oil is running down the valves


It will be fine to ride but keep an eye on your oil level

Posted

cheers guys.


To throw a spanner in the works - (having a cold I can't smell well at the moment) but from the way it moves and dipping a finger and sniffing really, really hard, I think I smell a whiff of petrol, rather than oil. It also doesn't feel very... oily.

I'll have another look when my colds gone and I get my glasses back (been blind for the past week and Its giving me a massive headache too)


I'll just hope they don't grit the roads for another week or so, because she's currently in pieces in 3 different locations haha


Thanks for the help all, look out for an update in a week

Posted

in that case are you sure its running down the valve?


oil in the air box will come from your crank case breather and it can smell of petrol


it will be on the left hand side as when its on the side stand thats where it will run


I have known for the oil to get past the air filter and run down the ports before so check your air filter too

Posted

I had an old Honda that had this, air filter was swimming with oil.

Even though I'd changed the oil, years of sub-standard servicing let it build up, so when I get a used old bike I generally replace all filters and fluids.


Clean out the air filter housing and replace the filter.

If that doesn't cure it you could have to just give the carb a clean and reset float heights etc.

Other than that you could have a coil starting to break down.


I always over service the bike... Service it as if petrolhead was the last owner. :thumb:

Posted
Service it as if petrolhead was the last owner. :thumb:

Essentially what I did as soon as I got the CG. Pulled everything off, checked it over, cleaned it up, and stuck it back on. Not so fun when it's getting dark in the evenings and raining every other night, but worth it!

Posted

It's a vital process very few actually do though.


Afterwards you know the bike and your work is your signature of approval essentially.

The issue is we do this work as other peoples approval is subject to much lower standards :lol:

Posted

Essentially what I did as soon as I got the CG. Pulled everything off, checked it over, cleaned it up, and stuck it back on. Not so fun when it's getting dark in the evenings and raining every other night, but worth it!

 

All that piss taking about mine been in bits over the winter eh


You are now starting to understand why and what I do it for ;-)


Keep up the good work :thumb:

Posted

Hahahahaha I know, I know :lol:

And the BMW is next in the queue... first order of the day is winching up the tail once again and removing every single moving part from underneath it to work out where that bast*rd creaking is coming from, then modify the battery tray to take a maintenance free battery (wrong shape for every one on the market, but the F650 forum has some instructions for doing it), then while I've got the front end in bits I'll give the valves a look, and maybe I'll finally take up Fro's offer of bashing together a tool to get at my steering head bearings. And change the tires and sort out the spokes, that's a bit overdue. Oh, and rebuild the brakes and stick some braided lines in. Should all be done in time for the rally if I'm lucky :lol:

Posted
Hahahahaha I know, I know :lol:

And the BMW is next in the queue... first order of the day is winching up the tail once again and removing every single moving part from underneath it to work out where that bast*rd creaking is coming from, then modify the battery tray to take a maintenance free battery (wrong shape for every one on the market, but the F650 forum has some instructions for doing it), then while I've got the front end in bits I'll give the valves a look, and maybe I'll finally take up Fro's offer of bashing together a tool to get at my steering head bearings. And change the tires and sort out the spokes, that's a bit overdue. Oh, and rebuild the brakes and stick some braided lines in. Should all be done in time for the rally if I'm lucky :lol:

 

calculate the cost of your time and parts and then buy a new bike maybe :P

Posted

calculate the cost of your time and parts and then buy a new bike maybe :P

 


your own time costs you nothing!


its when you are paying for someone else's time it becomes cheaper to buy a new bike :lol:

Posted

calculate the cost of your time and parts and then buy a new bike maybe :P

 


your own time costs you nothing!


its when you are paying for someone else's time it becomes cheaper to buy a new bike :lol:

 

well it does, think of the fun things you could be doing with that time, therefore there is a cost, albeit not a financial one. Basic economics, everything has a value/cost... its just how you measure it.


SO when your not working your are basically saying you are worth nothing??? that true?

Posted

majority of people do jack shit with their time and sit on their arses posting on forums or on Xboxes or ps4's


me included


so if your not doing nothing with your time then there is no value :lol:


swings and roundabouts really if your not using your time to earn money then your time is costing you nothing

Posted

As Stu said.

Also, the creak is the only thing that wants fixing. Everything else is improving the bike! The parts cost for the repairs is going to be £50ish for a bunch of bushes and bearings, absolute worst case scenario would be a problem with the shock or deflection lever then that'll cost a bit more but pretty unlikely. Either way, hardly "buy a new bike instead" levels of money :lol:

Posted

Ahhh the mysterious rear end creak.


I once took apart the entire backend, replaced every bearing, bush, and greased the lot.


Still creaked.


Have fun :lol:

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