Oily 2t pipe?

**george formby** · 30th January 2013, 20:07

Just a quickie. I was having a fossick around the Chancellors DT 230 today & found a build up of oily muck under the header, where the expansion chamber bolts into the head. I've also noticed a wee change in noise from the pipe recently, was not too worried as every 2t I have ever owned never really sounded the same twice. It does not seem to be revving out cleanly either. I could not get it howling yesterday in the forest & had to shift up early when it went flat at the top end.

Idle was a little high too but otherwise the bike runs fine. The bike is standard, I'm not allowed to put a different expansion chamber on it.

Any hoo, is this an indicator of something AWOL internally or just a case of needing to whip the chamber off & fit a new gasket? The bike is a 96 with 17'000 kms on the odo.

**unstuck** · 31st January 2013, 07:45

Could be just a gasket, or it may be a sign of something more sinister like crank seals or something going and letting a bit of gearbox oil into the cylinder. Good luck any how.

**george formby** · 31st January 2013, 15:21

Originally Posted by unstuck

Could be just a gasket, or it may be a sign of something more sinister like crank seals or something going and letting a bit of gearbox oil into the cylinder. Good luck any how.

I'm just about to take it off.. well, try. Sometimes those bolts can be barstewards and I'm not in the mood to snap anything.

**FJRider** · 31st January 2013, 16:25

Two strokes do that. The blue smoke they belch is burnt oil. Unburnt oil is also thrown out through the exhaust pipe. On older bike ... the expansion chamber gets clogged up. Thus loses performance.
There are various means of removing the carbon/oil build up. Repacement being the easiest.

**george formby** · 31st January 2013, 16:38

Originally Posted by FJRider

Two strokes do that. The blue smoke they belch is burnt oil. Unburnt oil is also thrown out through the exhaust pipe. On older bike ... the expansion chamber gets clogged up. Thus loses performance.
There are various means of removing the carbon/oil build up. Repacement being the easiest.

Yup, my first thought was its just the result of time, hard gasket, expanding & contracting etc allowing a bit of blow by. Sure enough me nuts won't budge, soaked in CRC as I tap. On closer inspection the cylinder head base is just a few mm below the pipe...... fingers crossed on the exhaust gasket rather than the head gasket.

**FJRider** · 31st January 2013, 17:06

Originally Posted by george formby

Yup, my first thought was its just the result of time, hard gasket, expanding & contracting etc allowing a bit of blow by. Sure enough me nuts won't budge, soaked in CRC as I tap. On closer inspection the cylinder head base is just a few mm below the pipe...... fingers crossed on the exhaust gasket rather than the head gasket.

It does this on GOOD engines. Not ALL the oil in the oil/fuel mixture is burnt.

On two strokes though ... the head gasket (the whole top end even) is NOT an issue.
If you have all the bits ... allow two hours. It may even be less.

Exhaust off.
Head off.
Barrel off.
Remove old rings.
relpace with new rings.
Barrel on.New head gasket.
New exhaust gasket (if it has one)
Exhaust on.

Ride ...

**george formby** · 31st January 2013, 17:13

Originally Posted by FJRider

It does this on GOOD engines. Not ALL the oil in the oil/fuel mixture is burnt.

On two strokes though ... the head gasket (the whole top end even) is NOT an issue.
If you have all the bits ... allow two hours. It may even be less.

Exhaust off.
Head off.
Barrel off.
Remove old rings.
relpace with new rings.
Barrel on.New head gasket.
New exhaust gasket (if it has one)
Exhaust on.

Ride ...

I should be done by 10pm then.. One of the reasons I really dig 2t's.

Good point about the rings, though. Bearing in mind it's a trail bike & only rarely gets caned what is an appropriate mileage to put new'uns in? I also know that new pistoons are like hens teeth so preventative maintenance is the way to go. Got a knickersill bore too, allegedly.

**FJRider** · 31st January 2013, 17:20

Originally Posted by george formby

I should be done by 10pm then.. One of the reasons I really dig 2t's.

Good point about the rings, though. Bearing in mind it's a trail bike & only rarely gets caned what is an appropriate mileage to put new'uns in? I also know that new pistoons are like hens teeth so preventative maintenance is the way to go. Got a knickersill bore too, allegedly.

If the bore is "well worn" ... a bike wrecker may sell you a half decent one.

If the slap isn't bad ... a quick hone is the best.

If its a hack bike ... just change the rings.

Some have just cut the exhaust in the middle (across the middle) and cleaned out the shit.then re-welded it together again. (time is money and all that)