Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[GaryBC]

It is hardly surprising the crankcase pressure built up to the point where it blew a rocker cover gasket - the entire breather system was bunged up almost solid!

Starting at the throttle butterfly housing and working backwards this is what I found: The 'bleed' hole into the inlet air stream had what I can only describe as a 'lava flow' of semi-solid crud running down the inner wall; the drillings in the housing body were stuffed full of sludge. The black plastic breather box was so bunged up (not one of the four internal pathways were clear) that I had to run a drill down the smaller two to clear them. Of the four tubes which feed the breather box only one (of the smaller ones) was clear (by blowing down them), the other small one - from the vent box, had to be 'drilled' out with a long screwdriver, as did the bigger bifurcated tube. The vent box itself was a problem as it was all but impossible to get at (even with the scuttle off and all the pipework tied out of the way)  but I managed to poke the small hole clear with a piece of wire, and shovel out a load of gunge from the big hole with a selection of screwdrivers! I kept digging until I could get no more out - in the hope that this will be sufficient. (I would have liked to have removed the vent box so as to flush it through but, even if I had managed to work out how to get it off, I'm not sure I could have got it back on!! Being right round the back of the engine and surrounded by a 'vipers nest' of pipes and tubes I decided not to try.)

Methinks this job has probably never been done since new (10 years and 185k miles ago) as, together with a new set of plugs, it has improved my motorway fuel consumption from 33 to 38 mpg!

I'll certainly not leave it that long again! The How To guide here suggests about every other year. But for next time I have a question: should I have persevered with getting the vent box off for a 'proper' clean? If so, how on earth does it come off?

Lastly, a great "thanks" to the writer of that particular guide - it is extremely clear and detailed. I couldn't have done the job without it!

Cheers,
Gaz

[GaryBC]

It is hardly surprising the crankcase pressure built up to the point where it blew a rocker cover gasket - the entire breather system was bunged up almost solid!

Starting at the throttle butterfly housing and working backwards this is what I found: The 'bleed' hole into the inlet air stream had what I can only describe as a 'lava flow' of semi-solid crud running down the inner wall; the drillings in the housing body were stuffed full of sludge. The black plastic breather box was so bunged up (not one of the four internal pathways were clear) that I had to run a drill down the smaller two to clear them. Of the four tubes which feed the breather box only one (of the smaller ones) was clear (by blowing down them), the other small one - from the vent box, had to be 'drilled' out with a long screwdriver, as did the bigger bifurcated tube. The vent box itself was a problem as it was all but impossible to get at (even with the scuttle off and all the pipework tied out of the way)  but I managed to poke the small hole clear with a piece of wire, and shovel out a load of gunge from the big hole with a selection of screwdrivers! I kept digging until I could get no more out - in the hope that this will be sufficient. (I would have liked to have removed the vent box so as to flush it through but, even if I had managed to work out how to get it off, I'm not sure I could have got it back on!! Being right round the back of the engine and surrounded by a 'vipers nest' of pipes and tubes I decided not to try.)

Methinks this job has probably never been done since new (10 years and 185k miles ago) as, together with a new set of plugs, it has improved my motorway fuel consumption from 33 to 38 mpg!

I'll certainly not leave it that long again! The How To guide here suggests about every other year. But for next time I have a question: should I have persevered with getting the vent box off for a 'proper' clean? If so, how on earth does it come off?

Lastly, a great "thanks" to the writer of that particular guide - it is extremely clear and detailed. I couldn't have done the job without it!

Cheers,
Gaz

Loadsa hits but no 'replies'! Anyone got any gen on my vent box query? In the How-To (http://www.omegaowners.com/forum/YaBB.pl?num=1152598350), towards the end, it's labelled "D" in the photo.

Cheers,
Gaz

[Liam]

I've got that head off so can see it clearly. It's fitted with some sort of grey sealant as I can see it oozing out of the join. Probably the same stuff that you use to seal the oil cooler lid. So you'd need to make sure you did a proper job with the sealant on refitting. To be honest I think it would be a horrible job with the engine fully assembled. Hell I dont even want to do it with the head off ! Suppose I ought to, though my beather system has no gunk in it at all. Sounds like yours is pretty bunged up with muck though! I could get a photo of mine if you like which would at least show you what you can't see.

[TheBoy]

I have never taken it off, not sure thats reqd tbh  :-/

Remove the gunk you can, and clear small hole

[GaryBC]

I have never taken it off, not sure thats reqd tbh  :-/

Remove the gunk you can, and clear small hole

Yeah, did that. I managed to clear the small hole with some locking wire until I could easily feed half an inch or so in and felt no resistance. As for the large hole; once I'd scooped out all the junk I could easily poke a screwdriver in for an inch or so. I didn't want to be too brutal as I believe there's some sort of carbon filter in the system somewhere and, in case it is in there, I didn't want to damage it!

Gaz

[Lizzie_Zoom]

Gary you are yet another member, along withmany of us, who has learnt probably the most important advise given on the OOF;  clean your breathers regularly!!

A straightforward enough job, but absolutely essential to the well being of our engines 8-) 8-) 8-)

[GaryBC]

Gary you are yet another member, along withmany of us, who has learnt probably the most important advise given on the OOF;  clean your breathers regularly!!

A straightforward enough job, but absolutely essential to the well being of our engines 8-) 8-) 8-)

Yeah! Aside from the bl**dy vent box, that is!!

[Liam]

I've ordered some grey sealant, so will have mine off and have a look and a clean. I should be able to tell you if poking a wire/screwdriver in 1/2" is likely to have done the job, then you can decide for yourself if you think it's worth doing. Sounds like yours was pretty bad so you might just have dug out two small 1/2" holes in a big solid mass of gunk!

[GaryBC]

I've ordered some grey sealant, so will have mine off and have a look and a clean. I should be able to tell you if poking a wire/screwdriver in 1/2" is likely to have done the job, then you can decide for yourself if you think it's worth doing. Sounds like yours was pretty bad so you might just have dug out two small 1/2" holes in a big solid mass of gunk!

That's exactly what I'm worried about! As you take yours off, you wouldn't like to take loads of pics as you go, would you?  

As I said, looking at it in situ I can't see how the heck it is possible to remove it (or, worse than that, re-fit the little beggar!).

[andyc]

Take the scuttle off and the wiper linkage out. Long 1/4 drive ratch and extension with small torx socket.

Big flat blade screwdriver to lever the exhaust heatsheild out of the way of the two outer screws.

Four torx screws and the breather will come off and you will need the oil cooler sealant when replacing.

I've gone one step further with my breather in that i drilled out the spot weld and popped to cover off, believe me after a 100k cleaning those two breather holes won't help that much and all that crud is heading back to your sump

i did do a write up in the ABS mag that some people have seen but haven't got the pics now as the PC died and i've lost them

If you want to know more about removing the cover let me know

Cheers
Andy

[GaryBC]

I've had the scuttle off a few times now - changing the HBV and then this weekend when doing the breathers and rocker gaskets. But I've never had the wiper linkage off - is that bit pretty straightforward?

And it sounds like the mounting screws are vertical - I presumed they go in horizontally from the back.

When you talk of bending the heat shield out of the way, is that a 'permanent' bend or does the screwdriver need to hold it back out of the way (against its natural springiness)? If the former, does it need to be bent back afterwards or can it be left bent?

Lastly. I bought a tube of the black RTV to do the rocker boxes. Will that suffice as a sealant?

Sorry for all the 'daft' questions but, as I say, it looks all but inaccessible in situ!! Does any other 'plumbing' not need pulling aside too?

It's a shame your pics have gone walkies as I'm sure they'd explain it all

[Andy B]

..... But I've never had the wiper linkage off - is that bit pretty straightforward? ....

4 hex headed self tapers. Be careful of the paint on your driver's side wing top as you remove the linkage, it passes very close by. 

[feeutfo]

i've had my breather box off at 100k. drilled the side plate off the original and fitted a nearly new one courtesy of yz250 on here, i have some pictures but there is very little of interest to see other than a couple of z shaped baffles and a rubber flap that does very little. IMO if you can blow through the breather pipes into the crank case, and the other way into the plenum, leave it be. If blocked force it through with a suitable thin intrument, mine had grown a seal over the inside of the small pipe making me think something was well and truely bunged in there. It wasnt, i was being too gentle.

Up to you, but if you do remove it, get the oil cooler grey goo, its more solid.

You may find the wiper mech the biggest chalenge tbh. Its a fiddle first time you do it and as Andy says, its dead easy to scratch the wing.

[Omegafantasy]

I just stopped by my workshop and took some pictures of my old engine and breather box.. Just in case anyone was curious 

I'm putting the links here instead of embedding the pictures, just to avoid cluttering of a nice thread..

Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 Picture 6 Picture 7

Hope this helps anyone

[tidla]

great piccies plenty of room thru the breather box, as said not worth removing for cleaning, a blow thru with the air line should suffice.

the mind boggles thou why it goes down to two piddley pipes when other motors just run a 1/2 tube to the air filter box?