Abuse-proofing a 525

[Ocean1]

Blocked tank breather?

No. Was also the 5th, 17th and 24th thing I tried.

Not going well, can't even find my fucking plug wrench, and I'm about out of time. Boys at the shop might get to sort it this time...

[dino3310]

the choke isnt stuck on is it.

[Ocean1]

the choke isnt stuck on is it.

Nope. It died just after a fairly hurried river crossing. Well, 2 min after.

And it died like it'd run out of gas, rather than the bullet-to-the-head usual when electrical stuff shit's itself.

It restarted 10min later, ran for 5 min and died again. Fin.

There's fuel flowing to the carb and it's getting past the float valve. The exhaust doesn't smell of gas, though, even after protracted cranking with the decomp open.

[Mungatoke Mad]

Nope. It died just after a fairly hurried river crossing. Well, 2 min after.

And it died like it'd run out of gas, rather than the bullet-to-the-head usual when electrical stuff shit's itself.

It restarted 10min later, ran for 5 min and died again. Fin.

There's fuel flowing to the carb and it's getting past the float valve. The exhaust doesn't smell of gas, though, even after protracted cranking with the decomp open.

Mine would suck water in through the air box at any sort of speed thru river & water filled ruts . I put a rain cover over the air filter & sealed up all the cracks around the air box with some sellys all clear[ Except on the drain ] it made a big difference just have to check the rain cover every now & then as it tends to ride up the side of the air filter & needs to be pulled down every now & then.

[Ocean1]

Mine would suck water in through the air box at any sort of speed thru river & water filled ruts . I put a rain cover over the air filter & sealed up all the cracks around the air box with some sellys all clear[ Except on the drain ] it made a big difference just have to check the rain cover every now & then as it tends to ride up the side of the air filter & needs to be pulled down every now & then.

Cheers, good to know.

Don't think it got a lungfull of water, though, I checked the airbox at the time and it was was dry. Ish.

Besides, it ran for a kilometer after that.

[Ocean1]

Whelp, apparently the cylinder's toast.

And the coolant was half gorne. Wasn't any noticable leakage though.

Working hypothesis: head gasket fail, poor old dear sucked it up, got too warm and ripped a trench up the cylinder wall.

Didn't seize, just did enough damage to lose enough compression to die.

Bugger.


Any tips on sourcing new cylinder/piston?

[CrazyFrog]

Awwww bugger, that hurts!
This one http://www.trademe.co.nz/motors/moto...-474155593.htm was on TM 2 weeks ago, sold for $300.

Option 1: Try looking up electroplaters to recoat the Nikisil coating on the cylinder and get a new piston.
Option 2: If you're considering downsizing to a 450 for the sake of a cheap rebuild, have a look at this one http://www.trademe.co.nz/Browse/List...x?id=481684717

Option 3: New factory parts $$$$

[Mungatoke Mad]

http://www.bits4bikes.co.nz http://www.motocrossparts.co.nz http://www.mxshop.co.nz

[Ocean1]

Awwww bugger, that hurts!
This one http://www.trademe.co.nz/motors/moto...-474155593.htm was on TM 2 weeks ago, sold for $300.

Yeah, saw that. Can wait a little for parts but given that it'll take me weeks to rebuild it I can't wait too long.

Option 1: Try looking up electroplaters to recoat the Nikisil coating on the cylinder and get a new piston.
Option 2: If you're considering downsizing to a 450 for the sake of a cheap rebuild, have a look at this one http://www.trademe.co.nz/Browse/List...x?id=481684717

Option 3: New factory parts $$$$

1) Not confident with the replate.
2) Downsize? Make it smaller? with LESS torque?

Are you serious?

3) Will avoid if I can...

[Ocean1]

http://www.bits4bikes.co.nz http://www.motocrossparts.co.nz http://www.mxshop.co.nz

Cheers dude. If I believed their front ends I'd say thy don't have any. Or much of anything else for that matter. Fortunately I can see that their sites don't work very well, so I'll give 'em a call.

Edit: any reason to not put a high-comp piston in?

[MXNUT]

Cheers dude. If I believed their front ends I'd say thy don't have any. Or much of anything else for that matter. Fortunately I can see that their sites don't work very well, so I'll give 'em a call.

Edit: any reason to not put a high-comp piston in?

Give these Guys a call http://www.o2engineering.co.nz/

They resleeved my DRZ400 barrel for me and i put in a forged hi comp piston. $270.00 for the sleeve.

Been in the automotive industry for 25 years and have never seen a sleeve job done with such precision.

Could not tell it from a new part.

[Ocean1]

Right. A re-chromed cylinder, piston, stainless valves and a camchain, (replaced on suspicion). Thanks to the guys at TSS for some nice work.

Took a wee run-in pootle down Karipoti and out the Mungatuk end to see the brother and back the same way. Had me worried towards the end, there, but it was just hitting reserve a tad earlier than anticipated.

Apart from being a bit of a bitch to start cold, still she's all good. Bit of attention around the valve seats seems to have paid off with slightly more rip up top and it's nice and crisp through the middle.

Bit of dribble on over-run since I put the DRD full system on it, must rejet to suit before too long. New oil and filters tomorrow and we're good to go.

[cooneyr]

Thread dredge but it is the only EXC thread in the Adv section.

EXC riders might be interested in these. Cush drive real wheel being the useful bit. Should slot straight in with your current axle (pre 2008 model EXC - not sure about 2008 on)



http://www.trademe.co.nz/motors/moto...-523620003.htm

Cheers R

[Ocean1]

Not a bad price if it don't go much over the startong price.

That rear looks big... can't be a 19", though.

[cooneyr]

Not a bad price if it don't go much over the startong price.

That rear looks big... can't be a 19", though.

All 640 E's that I know of have 21/18 combo. Be good deal for start price.

Cheers R