whats that noise?

[fishtail]

you know I had an off - and some seriously high reving dieseling occured... well I put new bars on - beautiful yes..

got on bike- hadnt ridden it really since bending the bars ...

engine wanted to rev its nuts off all the time.. only got down the road... and turned around came home... dieselling left right an center as soon as pulling clutch in... had a look, couldnt see any air leak.. decided to clean carb - and put new throttle cable on ( it wasnt sticking but I had a new cable and saw it was frayed.. )

this solved *that* issue.

but......... now a new ominous noise has reared its head... is becos of some prolonged engine creaming screaming??

http://www.youtube.com/watch?v=7LwpPbhcUBc

sounds like its around the cyclinder head area..

actually sounds like a diesel estate illegal cabby....

[njhardy]

Sounds like piston slap/a loose bearing to me...

[helisupp]

That engine needs a visit to the emergency department, lets face it, it deserves it.

I think it needs a full engine rebuild with new bearings, and get rid of the welded gearshaft, and then you can play with gearing.

[knackeredMk1]

+1 it's time to split the engine. It's been overdue for a while now. Make sure you do it properly and don't rush it to get back riding .

[fishtail]

looks like I'm banned from here until I do it then!

actually its come at a terrible time,, I am sooo friggin busy for the next 2 or 3 months,.. of course even when busy I can sneek of to my local for an hour.. ( like I did today! whoo! )

how many hours work do we guess this is? I dont have a garage.... ( that guide someone posted suggested around 8-9 hours to remove engine and crack it open,. then at least as long to put it back toether - factor in the fishtail fingers and we looking at least treble right... ( luckily no salt on roads here so that swing arm bearing of legend is prob ok....... )

I'm sort of considering 2 options...

1 buying a reconned engine... and putting it in... ( anyone got a *nice* mk3 engine? )

then fixing mine up as and when I have time., swappin it back for legal reasons...


2 - paying some one to do it ... actually I kind of wanted to do it myself... jus becos it would satisfy me to know that I could do it ( hmmm like I swapped the piston over ? )

3 - buy another bike to fart around on whilst I fix this one up...., suppose another mk3 might be a good idea?

[pudzie83]

bearings matey think shes about to lock up my mates kx 250 sounded like a taxi at apex track the other week that completely seized and took the engine casings with it...huge mess to sort out

[pudzie83]

good excuse to replace the welded shaft as well

[knackeredMk1]

The trickiest things to do if you do it yourself are getting off various high torque nuts/bolts (impact wrench) and getting the bearings out of the cases and back in. If you can do these then DIY.

I would suggest that you change all the main gearbox/crank bearings whilst you're at it.

Buying a new secondhand engine comes with all the concerns as you are aware so might be a false economy.

In terms of time:

Take engine out - More than 1 hour less than 2.
Split engine - 30 minutes if you have the tools.

And the same in reverse but nearer one hour to put the engine back together BUT considerably longer if you don't have the correct tools.

Just be sure to think about what needs to be done before you go ahead all guns blazing. Sometimes it is much easier to parially dissemble the engine and take the high torque nuts/bolts off whilst you can still use the chain/brakes to stop the shafts turning rather than take the engine out and be stuck. Also it's easier to plug the oil feed tube at the pump than to draining the whole system (though with the Mk3 you can just take it off).

Have a small strip of aluminium 1-1.5mm thick to use as a chock between the gears when tightening and loosening.

[fishtail]

ok! thanks steve.. I think once I go in - I will swim...

I got a plan of sorts...

risk of seizing sounds shitty! is that a real threat? or if I take it easy might limp on for a week?

gonna have to order the athena gasket kit ( why oh why didnt I order it months ago )

[pudzie83]

if your engine does seize the cost of repair could double my old tzr 125 sounded worse than that and ran till it wouldn't go past 30mph when stripped i had half a ring left a 50p sized chunk of piston missing and all bearings were more or less shattered but it wouldn't die. while last year i was riding my crm to a track and the rings just went no noises or any signs the odd thing was she started first kick which its never done from cold

2strokes are unpredictable yours could last or it couldn't but its a case of fix her now for normal rebuild cost or risk a higher rebuild cost later on

with my experience of recking engines (5 alone just on my tzr) i would opt for the fix it now option

[fishtail]

yeh kit ordered

thing is wont know what I'll need once I get in there?

small end only a few months in - so probably ok? unless I fºcked it up? could I fºck it up? wouldnt it have blown up earlier?

or the rings have broken? so the piston is slappin about? ( oh dear another rebore - can I make it BIGGER? )

sounds like top end tho.. or could it be big end bearing ? but thats a specialist job right..

was supposed to meet a mate an show em my local track I 'found' - I might risk pootling down the road,, only 5 mins away whilst I wait for the gasket kit to arrive...

( hmm but is it better to get in sooner incase of sourcing other parts? )

and thanks steve,, I may have some specific questions once I re read that 'how to split the CRM guide' a few more times

I got impact driver - torque wrench,. must RTFM

[pudzie83]

best way of testing the mains is to remove your flywheel cover and move the flywheel up/down side to side there should be no play at all. The small end bearing is only a few pound so its worth replacing anyway.

cant say about the bore till its in bits there isn't really a way of testing it apart from compression test.

[pudzie83]

if its mains the crank will require splitting and pressing together which requires skilled hands and specialised tools

[Carbguy]

Hey fishtail!
Do that rebuild man. I dont have a garage either. Had just a wooden table and
A workbench. Sockets and wrenches and a good hammer. Made my own gaskets have
No leaks and she runs well. You just need http://www.crm250.com and some motivation.
(by the way, change that welded shaft . )

[knackeredMk1]

One more bit of advice - Bag the bolts as you take off each part and bag the parts in different bags. E.G bag all the whole output shaft in one bag and the whole clutch shaft in another, all the clutch together, kickstart together, etc etc ....