Oh dear, is my Bore stuffed??

[cheese]

It looks like some sand got into my exhaust port and I've got a few lines on teh bore. Bike is a RM250

Question 1

Will need to get a new cyclinder? or can it be fixed?

Question 2

is this going to cost me shitloads?

[Brian d marge]

Depends on how deep they are and what type of Rm .....everything can be fixed ,,,for a price

Stephen

[skidz]

If it's not too bad, just get it honed out.

[Racey Rider]

Sand. Thats nothin!
Try having a spark plug in insolator fall ontop of your screaming piston and see what kind of marks you get in the bore.

My (plated) barrel has been sratched to bits. But having no money to fix it properly, I just sanded it down with a drill attached sanding wheel.
While this method is not ideal, the motor still worked fine and pulled well.
You will lose a small amount of compression as the gases slip passed the rings at the sratched area, but you won't even notice any little lack of power.

My motor is still a learning tool to me, and this last time I sanded it I made the mistake of getting to keen in one area. This ment the rings couldn't 'seat' into the sanded groove I had created. Which allowed to much 'blowby' and caused problems. So make sure your sanding is even around the diameter of the bore.
Thats the cheap way. (Hey, somebody gota try these things)
I'm still learning what works and what doesn't, and that barrel patching process was working for me. (till I over did it)

Of course, if you want your motor in top condition to get that last hoof of power out of it. Spend the money to fix it properly, or buy a new bike!
Racey

[Motu]

An RM of that year most likely has a plated bore,a very thin layer of nickel over the alloy - you can't rebore or hone,just clean up.You have to send them to Aust for replating.A steel bore can be rebored to a bigger size,or if the damage is light a hone can help - so,steel sleeve or plated?

[cheese]

Sorry I waz very vauge wasn't I....

Bike is a 98 RM 250

yes it's got the plated bore.

I've attached some pictures.

By the way, this site friking rocks!!

[Brian d marge]

From the pictures the bore doesnt look to bad you may get away with a light hone ..though the plating is hard , th e hone will clean it up a little ...or a little bit of wet and dry on the really rough spot ...DONT go crazy u are just taking and high spots off

The piston on the other hand looks like its picked up ...You could use it at a pinch IF IT AINT CRACKED ...the performance will suffer as will the heat transfer ,,,but unless u are nailing the snot out of the gates ,,,,the engine als may be a bit noiser,,,

Check out the price of replating ...and i am sure I can guess what your choice will be!!!

Stephen

[cheese]

Ok I took it to the good bastards at colmans and guess what the bore is ok!! a light hone will cost me about $20 and I'll be away!! Yay!! I've got a new piston kit on the way and so that will be sorted. The piston was ROOTED!

one thing that I'm really spewing about is that the bike isn't even a fucking 98 Rm!!! it's a 96!!! I could kill the fucking wanker I got it off!! So I ordered the wrong piston and look dam stupid!!! But the great guys at colemans have taken back the old piston, ordered me a 96 manual instead of the 98 one I was going to get and been really good.

Grrrrrr

At least by the time I've done this the bike will be mint. I'm going to do all the swing arm and neck bearings to be safe I think. May as well get it in tip top condition now I own it.

I will really think twice before EVER buying private again. I'll check frame numbers and make sure it is what it's being sold as.

Do you think I should hit the guy up? get some money back? I paid $2600

BTW, thanks all you guys for your fantastic fast reponses!!!

[Motu]

Yeah,sucks finding that out - but it's hard to tell on an off road bike,unless it has road registation.Unless you know the model really well or do a frame number check the incorrect year can get handed down from owner to owner word of mouth.

[vifferman]

Unless you know the model really well or do a frame number check the incorrect year can get handed down from owner to owner word of mouth.

.. or just guessed at, if the previous 'owner' didn't actually buy it....

[cheese]

Na it's not hot. Think the guy just got told it was a 98 and never did a piston himself so never found out.

I'll give him a call tonight and let him know what I think of him.....

[Ixion]

..
one thing that I'm really spewing about is that the bike isn't even a fucking 98 Rm!!! it's a 96!!! I could kill the fucking wanker I got it off!! So I ordered the wrong piston and look dam stupid!!! But the great guys at colemans have taken back the old piston, ordered me a 96 manual instead of the 98 one I was going to get and been really good.

..

I will really think twice before EVER buying private again. I'll check frame numbers and make sure it is what it's being sold as.

Do you think I should hit the guy up? get some money back? I paid $2600

BTW, thanks all you guys for your fantastic fast reponses!!!

This could be complete good faith. The 96 will relate to the year of manufacture. If a bike is made at the end of 1996, sits around the manufacturers place a bit, then gets shipped out to New Zealand, sits in a dealer's show room and doesn't sell, he finally gets a buyer and registers it at the beginning of 1998. Easy to happen and does. We're at the end of the world, maybe three months shipping time, and some bikes don't sell fast.

[cheese]

I could accept that with a say end of 96 bike and sold as a 97, but there is a HUGE difference in 96 and 98.

At the end of the day it was false advertising and he must have known in some way or another when getting bits for it.

[F5 Dave]

Well it never gets registered -as it's an MX bike.

Check the brake lines & the rims, often they have the year of manufacture on them & the suppliers of these will not keep heaps of stock, it will be just in time supply to Suzuki or where-ever.

Go on check your bikes guys, - neat trick huh?

One would like to check the airbox, airfilter & how well it & the connections to it seal. New filter & reasonable amount of oil on filter.

To hone a plated bore you need the right type of hone & a light touch. I prefer a bit of scotchbrite & not too much. Obviously while you have it apart clean the powervalves & check they are not too rattley, lest they fall into the piston. Any doubt check with the shop.

Also the recommended sparkplug is the hot tip, regular plugs tend to suffer vibration on RMs of about this age & drop into the cylinder. They aren’t cheap however.

[cheese]

Cheers mate

I've got a new filter, cleaned teh shit out of the old one, got a new plug, replacing all the linkages tomorrow (cheers spectrum) Getting the shop to rehone the cyclinder, putting new piston in, getting the power valves checked and so my $2600 bike is now a $3500 bike....