Ceased piston

[KTMAndy]

Well, I'm certainly gaining my maintenance badge with this little gasser. Today heading out for a bit of green laning, the piston ceased. All I can think is that one of the jets became fouled and stopped oiling the head.

Ah well, so tomorrow, I get to take it apart game on!! I'm expecting to find the rings stuck in the barrel. Hopefully, that will be it. It made the screech, I grabbed the clutch and rolled to a halt.

I've found several pistons on eBay, from ?90 to ?180 does another piston fit the bike? It does look very much like a crf bottom end, but I'm no 2t expert by any means.

Can anyone tell me if another piston and ring will fit my 05 Gasser 250 EC if so, what would you suggest?

Cheers.

Andy

 

[desertgasser300]

There are some recent threads about a Honda cr250 piston fitting, but with some skirt issues I believe. Honestly I would just go for a piston built for your Gasser. They are floating around Ebay here in the states, not sure about the U.K.

 

[noobi]

Something like this would be what I would use. http://www.ebay.co.uk/itm/Gas-Gas-M...ycle_Parts&hash=item45fe143cc5#ht_1531wt_1037

or from these guys http://www.trialendurodirect.com/products/15_17/S3_RACING_longlife_pistons_256.html

I just tend to go with a brand that iv heard of before, having worked in the industry im sort of aware of whats good and whats not.
I would be wary of Mitaka stuff, not that its good or bad, but it is cheap.
If you can find a Wossner or vertex piston kit that includes the necessary gaskets, id go with that, just because its easier.

Also, there are no oil jets in the head of a 2stroke, it gets oil from the premix. If the piston seized, then something else must be amiss, probably with the jetting being too lean.

 

[myrcrocks]

Also, there are no oil jets in the head of a 2stroke, it gets oil from the premix. If the piston seized, then something else must be amiss, probably with the jetting being too lean.

Or, the piston has just lived its life cycle... Even a properly running 2T requires a top-end rebuild after time... How many hours on this particular piston? How was it running?

 

[Diggs345]

Hi andy

I talked to you last week via email , your not having much luck with that bike lol , if its run ok so far i would rule out a jetting problem , like the other guy said the piston may just have outlived the cylinder and you may find one of the skirts has disenegrated , with a bit of luck its just nipped up.
Did the engine turn over after this happened with less compression or was it siezed solid.
I normally put a new piston and rings in when i get a new bike just to be on the safe side , or shortly after for peice of mind.
Im stuck in scotland for a couple of weeks at the moment or id be happy to help you out .
Rgds
Chris

 

[KTMAndy]

Thanks for all the suggestions and advice guys, much appreciated.

The bike had been running fine, i rode it the day before with no sign of a problem.

Yesterday, it was a pig to start, it kept dying, I thought it was a spark issue, but ruled that out, it was kind of cold, so I persevered thinking it must have just been cold.

When I got it running, it did eventually come to life and was pinging along but with the occasional dip in revs.

About 5 miles towards my destination it died, no bang or clunk, it felt more like hitting the kill switch, as I was on a main road, as it started to die I hit the clutch and rolled to a stop.

It was when I tried the kick start I realised it had ceased.

I did the long lonely walk home pushin the bike the 5 miles home. There aren't many hills in Scunthorpe... But just for Chris, I had to push it up Doncaster road... By the time I got home, I needed a new piston and set of lungs.

So today, I start investigations into what and where it went wrong, most importantly why.

 

[Jakobi]

Hard to start, running cold, pinging along, surging revs. All points to being on the lean side to me. Hopefully its just nipped up and hasn't done too much damage. Did it turn over again after things cooled down?

 

[Diggs345]

Thanks for all the suggestions and advice guys, much appreciated.

The bike had been running fine, i rode it the day before with no sign of a problem.

Yesterday, it was a pig to start, it kept dying, I thought it was a spark issue, but ruled that out, it was kind of cold, so I persevered thinking it must have just been cold.

When I got it running, it did eventually come to life and was pinging along but with the occasional dip in revs.

About 5 miles towards my destination it died, no bang or clunk, it felt more like hitting the kill switch, as I was on a main road, as it started to die I hit the clutch and rolled to a stop.

It was when I tried the kick start I realised it had ceased.

I did the long lonely walk home pushin the bike the 5 miles home. There aren't many hills in Scunthorpe... But just for Chris, I had to push it up Doncaster road... By the time I got home, I needed a new piston and set of lungs.

So today, I start investigations into what and where it went wrong, most importantly why.

You must be fitter than me , id have been in a&e long before pushing it 5 miles , when you take the cylinder off make sure it hasnt taken any of the plating off when it siezed .
Hopefully your sorted when im back home so you can show me some trails .
Chris

 

[KTMAndy]

Piston and cylinder head are fine, though I will be replacing it while there off, the problem is in the bottom end, I need a pulling tool to pull the stator off, to get any further, as the engine needs to come out.

The nylon shrouds on the crank have destroyed themselves, I can turn the crank round but its stiff as hell.

Currently looking for conrod and big end kits, but before I start buying stuff I need the engine completely split.

 

[savage sausage]

If I were you Andy I'd ring the shop were you bought it from and explain you have only had it 2 weeks and get th to stump up at least half of it, as they should check all the bikes correctly before sale.. look at the sale of goods act

 

[Neil E.]

I'd like to know what test could be done to judge the condition of those plastic parts. I assume they are a form of case stuffer to reduce crankcase volume. What years of bikes had them or are they still in use?

 

[Dockillemall]

Right side main bearings, common problem to GasGas including trials bikes.

 

[KTMAndy]

Already on that buddy, it's Sunday and there not open, but I want to return them a knackered crank, and let them replace the bearings, conrod and crush bearings.

I've sent them an email, out lining that, it won't cost them a fortune, they will have the tools to do it and it feels like a decent compromise.

Not sure where I stand with my statutory rights on a used enduro bike, but I get your point, after 10 miles it's gone bang so it's not fit for purpose.

 

[KTMAndy]

Right side main bearings, common problem to GasGas including trials bikes.

I think you're bang on with that pal, looking at the crush bearings, it looks like ones collapsed and sent the conrod off at an angle, destroying the nylons, but I guess, that's why they are there.

 

[noobi]

I think you're bang on with that pal, looking at the crush bearings, it looks like ones collapsed and sent the conrod off at an angle, destroying the nylons, but I guess, that's why they are there.

Cranks are expensive, hope fully is hasn't been damaged.
The bearings and seals are off the shelf items from any bearing shop.
The rod is a direct crossover from a CR250, youll find the exact year by having a look around on here, this was discussed not too long ago.

 

[savage sausage]

Already on that buddy, it's Sunday and there not open, but I want to return them a knackered crank, and let them replace the bearings, conrod and crush bearings.

I've sent them an email, out lining that, it won't cost them a fortune, they will have the tools to do it and it feels like a decent compromise.

Not sure where I stand with my statutory rights on a used enduro bike, but I get your point, after 10 miles it's gone bang so it's not fit for purpose.

I once bought a BMW and it was sold to me by a garage, I had a friend with a garage to put it on some ramps to have a look underneath as who takes a jack and overalls to buy a new car??

He told me that the brake lines were f*cked and it would not pass an MOT so I got back onto the garage who sold me it I quoted the "Sale of goods act 1979" and told them they had a duty to sell me a vehicle in roadworthy condition, of course when I rang them they told me to F Off, but knowing I got upto ?100,000 legal costs on my home insurance ( check yours ) went back to them and advised if they did not fix it I would persue them in a court of law.... of course they backed down and fixed the car at their cost plus my diesel to them and back.

I'd speak to the dealer and explain that you are VERY UNHAPPY that this has happened after just 10 miles and that you want something to be done about it, if they give you the old line "well it was alright when we looked at it" request a report that has been carried out on the bike chances are there is no report and you can chellenge them on how they thought it was "alright".

Check your home insurance and you'll be suprised what it covers, thats if you took out the extra legal cover for ?20 odd quid ish.

Next up go down to the dealer in person request to speak to the sales manager if you are told he is not there then make an appointment to see him give you name and number and request a callback, list all your actions time date etc, so if you do have to take it to court you have evidence.

Explian that you heard they had a good reputation for customer service thats why you bought the bike from them, gauge the reaction if they look at you as if to say F off then thats when you need to take control and advise them of your rights as a consumer and that you will take legal action and make sure that other potential buyers are put off buying in that shop.

1. You spent X ?000's of pounds on a secondhand new bike from a dealer
2. It's seized after only 10 miles
3. You should be p1$$ed off
4. they have to make sure what they are selling is in a saleable condition
5. know your statutory rights as a buyer.
6. demand they fix the engine or tell them you want a full refund!!

If you need any help message me fella

Regards
Simon

 

[Diggs345]

Those plastic things are crank stuffers , they are used to reduce the crancase volume , was the small end bearing ok .
Where did you buy the bike , pm me if you like .

Chris

 

[KTMAndy]

It's from Ras Sport in Brigghouse. Little end bearing seems fine, but I'll still replace it. To be honest, I'm no mechanic, but I'm enjoying the learning curve that im going through lol. It's all good experience. I will be chasing the garage for some costs/parts they seemed decent enough when I had a problem with a bent gear lever, offered to replace, but I straightened it up easy enough.

There's a place in Bradford that do crank rebuilds for ?120 including parts (if you take it to them) when it's out, I'll take it there.

Anything I need to watch out for putting it back together?

 

[savage sausage]

It's from Ras Sport in Brigghouse. Little end bearing seems fine, but I'll still replace it. To be honest, I'm no mechanic, but I'm enjoying the learning curve that im going through lol. It's all good experience. I will be chasing the garage for some costs/parts they seemed decent enough when I had a problem with a bent gear lever, offered to replace, but I straightened it up easy enough.

There's a place in Bradford that do crank rebuilds for ?120 including parts (if you take it to them) when it's out, I'll take it there.

Anything I need to watch out for putting it back together?

My advise is dont touch anything else on the engine, take it out and take it to them 'as is' ...ideally you should have left it be as one complete unit.

let them sort it all out otherwise this little escapade could end up costing you lots of money.
You want to make sure that the work you get back is guaranteed in some way.

 

[Diggs345]

If you havnt split the cases before i would leave it to someone else , ras sport will have all the kit to do that , i have home made tools to do the job but im away unfortunatly , you will need a case splitter and flywheel remover , dont even think about using levers lol