The CR saga for me continues...engine frozen

[-df-]

Well, after the last thread I thought I'd take her out to the beach on Sunday...had a blast hooning around on and off for about 30-40 mins. I stopped for about another 30mins and had a ciggy and chat to mates. Came back to the bike and tried turning her over (the engine was dead cold)...no life at all. Tried for about 5 mins kicking her over with no luck, then on my last kick over the engine seemed to seize on me...no movement in the engine it seemed with the kickstart locked.

So after a couple of words (and doing something to the bike as I wasn't to happy...but we wont go there...) pushed the bike back along Muirawai beach and back to the trailer.

Finally went back to check out the bike, made sure she wasn't hydrolocked, tried kicking it over again, no movement still, so I put it in gear and tried to turn the wheel, there's the normal movement in the chain, and then there seems to be some movement in the piston (was stoked when that happened ) then a clunk like something is stopping it turn over, turn the wheel the other way and the same happens, normal movement from the slack in the chain then piston moves then a clunk...

Ok...now comes the hard part...anyone got any ideas?

My thoughts are (note: bike has just had new kickstart gears installed by prev owner) something in the kickstart is jamming the bike, presume there has to be a one way release type thing so that when the bike starts it disengages the kickstart. The kickstart has no movement at all...its locked (where then engine seems like it has some movement in it before the "clunk").

My only experience with engines is rebuilding car engines...so the whole kickstart 2 stroke thing is new to me.

[barty5]

could be conrod and piston are no longer one in the same (they have seperated hence turns over small amout till conrod locks up on barrel pull head off easy quick job to do sound like its got to come appart away

[cheese]

just sounds bad......

2 strokes are dead easy to work on. Just strip her down. Maybe start with the cyclinder or maybe the side cover where the clutch and kickstart are?

[WRT]

Mine had similar symptoms a while back. Turned out the piston skirt had disintegrated and little bits of it had jammed the crank shaft. Also, as you say, double check the kickstart mechanism, doesnt take much for that to lock up the whole she-bang, however I would have thought it would have done it before now if it was replaced a little while back.

As Cheese says, 2/'s are easy to work on. Just start stripping it down. If you've done a car engine before, you will be amazed how easy this is.

[Reckless]

yep as they say strip it down. Start at the top end and go on from there.
Seat off, tank and shrouds as one, radiators. Then the barrell (you can leave the head on). Then dig deaper from there. Look carefully for any missing bits like c-clips as they will be down below. Hopefully they have gone straight down and not up and down the bore a few times. If its not up top at least you can now check the top end for wear and chuck a new ring in.

Have both my Cr's in bits.
CR125, 31 hours, measures just under new, but way over wear lmit, so just needs a ring.
CR250 piston measures within new tolerances, done 53 hours, so rings, pin and bearing. I'll strip the KX85 2night.
I know some of you chuck pistons at them everytime but 20 years karting, high compressions, 5-6000 over factory revs, methenol etc have taught me sticking to manufacturers hours, only means they can sell more parts.

Good luck with your bike!

[Danger]

Sounds to me like its in the kickstart mech. I would pull the side cover off and have a look at that before pulling of the top end. Its easy to stuff up the installation of those if inexperienced.

[Reckless]

Yes very good point Danger.
Check on the clutch, in case its lost a wing off the basket etc and the alternator side to make sure something hasn't come loose and the other simple things like driveline. Good thinking Danger!

Warning to all!!
40 mins on the beach is probably the hardest on a 2 smoker.
Often very high revs, maxed out in all gears, not much decelleration to let the cooling effect if the idle jets/fuel/air work, High revs & no cooling wind when doing donuts, hard on the gas doing wheelies, usually for a lot longer than doing hard out MX racing or karting. Its not often even an MX racer will hold the revs, for the time, you will on the beach. All adds up to a lot of revs, heat and hardship on the engine.

[-df-]

Warning to all!!
40 mins on the beach is probably the hardest on a 2 smoker.
Often very high revs, maxed out in all gears, not much decelleration to let the cooling effect if the idle jets/fuel/air work, High revs & no cooling wind when doing donuts, hard on the gas doing wheelies, usually for a lot longer than doing hard out MX racing or karting. Its not often even an MX racer will hold the revs, for the time, you will on the beach. All adds up to a lot of revs, heat and hardship on the engine.

Hmmmm, might have to rethink the beach after hearing that, never thought of it like that but makes sense.

[-df-]

Sounds to me like its in the kickstart mech. I would pull the side cover off and have a look at that before pulling of the top end. Its easy to stuff up the installation of those if inexperienced.

update: pulled the side cover (small one) off the kickstart side, turned the wheel, definatly moving the gearbox gears, yet the kickstart is jammed up tight so that sort of tells me that the piston/conrod might be all good (here's hoping, its only had 10 hours on it including a new barrel!!)

Can someone tell me where the drain for the radiator is? I'm either blind or they dont have one and I have to just pull a hose...

Also, seeing as I don't have a manual for the bike sitting here right now can someone tell me if I need to remove the water pump first or if I can just pull the whole cover section off? Just trying to find the right alan key for removing the rear brake lever now...why can I never find the right one when I need it!!

[-df-]

update 2: ok, kickstart is now turning her over the same amount as moving the back wheel...so much for that theory...about to remove the head and have a look.

(ps: decided I can't not look at the bike...everything else is just going to have to wait )

[Reckless]

you don't say on here or your profile what year etc your CR is.

But the drain for the water is usually on the side of the pump itself. Should be a 10mm bolt head with a cooper washer under and probably a pozi drive(phillips head) shape in it aswell.

Pump should come off with the cover, but some of the bolts may go all the way through as part of the mounting bolts for the main cover.

Also try taking the plug out, put it in gear, put a bit of straight wire down the plug hole onto the centre of the piston, long enough not to drop in, turn the wheel slowly, see if the piston pushes the wire up and down. That'll test eveything is connected to the piston but not if a bit is broken off. If this works maybe spend a bit more time envestigating the kick start etc.

If it doesn't just shout FFFFFUUUUUUUCCCCCKKKKKKK!!!!!!!!

[B0000M]

radiator drain is the bolt on the right hand side motor, the water pump is the bulgy little cover at the front, on that cover there will be a bolt with a phillips head on it as well, undo that one, its the drain.

the other one further back is the trans oil check mark

[Reckless]

Doesn't sound good. Sounds like something has shit itself and the crank is only turning 1 revolution each way.

By the way the beach is ok just let the bike breath and cool between thrashing's. Like with a gentle ride for a k or so to let the barrell and water temp go back to normal. Thrashing it and swtching off hot is the worst as more heat is generated when the water and pump have been stopped before the engine has normalised.

[cheese]

yeah a 2 stroke really doesn't liek to be on teh beach with the gas held open for long periods of time. THis is possibly the most common way people blow up 2 strokes. it leans out and BANG!!

You can find some online diagrams of your bike on the web. I'll see if I can find something

[Brian d marge]

most likely the piston conrod is going to be ok . head off have a look , ( if remove the barrel then then its a tad more difficult as you have the Hpp gear to line up .

Then next try alt cover , a jammed flywheel easy to look at .
all those ok ?

Then LH cover off and check Kick start Idle gear and crank shaft pinion gear for something jamming .bent etc

Be careful putting it back together , the HPP gear needs to be lined up correctly , it can go back together and look like its working , but will run like crap as the gas pressure is opening the port valves ,,

all the bottom ends I have seized have flattened the needle roller bearings and will turn over , though when started up ,,,sound awful ( But will finish a race !!1!! )

I assume its the 91 cr you are talking about


Stephen