G5 blue smoke and plug oiled.

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Re: G5 blue smoke and plug oiled.

Postby SPRIDDLER » Sun Jul 07, 2019 9:14 pm

Yes you can use the gasket several times provided that it isn't damaged.

Copper 'age hardens'. I once worked as a storeman in a plumbing suppliers and the time-served old boys wouldn't take the older darkened copper tube as it wasn't easy to use/bend. They insisted upon having bright shiny tube.
Anneal (soften) the gasket by heating all of it to cherry red then either dropping it into cold water or leave it to cool naturally. It doesn't matter which but dropping a used gasket into water will shock off any sooty dirt.
I use my gas cooker. For some reason the flame and the gasket's cherry colour don't show in the photo......

Head gasket heating in pliers (640x427).jpg


The dish is full of water........

Head gasket cooling (640x480).jpg


The whole gasket above is annealed. I took a second grip of the gasket in a different position and heated it but it shows darker by one bolt hole.

As far as the oil goes I would guess if the level dropped 3" ( :shock: ) in a couple of minutes it's likely to be a scavenging rather a burning issue but I cannot see why it would do that just by replacing the head gasket. Draining the sump will give you a good clue as to where it's gone.
I've never had or worked on a L/W so won't venture any further into the oiling issue ;)

Edit:
vigo wrote:Recently bought this bike it had lost compression. The headgasket had been in correctly fitted by previous owner.

Is it possible that the oiling fault was there or developing already?..... If the P.O. fitted a head gasket incorrectly...... :?
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Last edited by SPRIDDLER on Sun Jul 07, 2019 9:32 pm, edited 1 time in total.
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Re: G5 blue smoke and plug oiled.

Postby vigo » Sun Jul 07, 2019 9:31 pm

Thanks Spriddler, good advice. The gasket I have is integral with a fibrous surround, do I seperate the 2 materials before annealing? As far as scavenging goes I've only had the bike weeks and took it with blown gasket so there could be a pump problem. Tomorrow see if any oil in sump. Cheers, Mike

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Re: G5 blue smoke and plug oiled.

Postby SPRIDDLER » Sun Jul 07, 2019 9:39 pm

vigo wrote:The gasket I have is integral with a fibrous surround, do I seperate the 2 materials before annealing?

Oh dear. I've not had an engine with a composite gasket but I'm 99% sure you mustn't separate the gasket layers. I may have given you a bum steer about the annealing for your composite gasket :oops: . I've led a sheltered shed life.
You'll need to wait for advice from one of our very knowledgeable L/W owners.

Having re-read your previous posts I'm getting a suspicion that there's something not right with the oil pump. Possibly an incorrectly fitted or very worn guide pin or blockage. That'll be another line of checks though (to which Paul has given you a link).
Last edited by SPRIDDLER on Sun Jul 07, 2019 9:58 pm, edited 2 times in total.
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Re: G5 blue smoke and plug oiled.

Postby clanger9 » Sun Jul 07, 2019 9:50 pm

You should (hopefully) have fitted a new, modern composite gasket. No need to bother with the solid copper type any more.
It's normal for the oil level to drop suddenly when you start it. It should come back up again once the oil scavenge starts.

Can you see the oil returning through the small hole in the oil tank (just below the filler cap)? That will confirm that it's scavenging properly.
If not, there is some good info on diagnosing Lightweight scavenging issues in this thread: viewtopic.php?f=16&t=24918
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Re: G5 blue smoke and plug oiled.

Postby SPRIDDLER » Sun Jul 07, 2019 9:55 pm

Thanks for bailing me out Paul ;)
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Re: G5 blue smoke and plug oiled.

Postby vigo » Wed Jul 17, 2019 7:06 am

Drained the sump there was 3/8 of a pint doesn't seem enough to be or cause my problem. Poured it into tank which left about 1 inch missing ie 2 inches from top. Important info I didn't mention. On refitting the head after gasket replacement, the 5th bolt ie only bolt, the rest are studs, I'm pretty sure the thread was stripping male or female not yet sure. No external oil leak but could that allow oil to migrate into cylinder area past copper head gasket and what action if female thread is stripping?

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Re: G5 blue smoke and plug oiled.

Postby clanger9 » Wed Jul 17, 2019 5:03 pm

I did run mine with the 5th head bolt missing and it was fine - however, it's obviously better if the bolt is fitted. You can get the barrel helicoiled easy enough if the threads are stripped. Before doing that, I'd try a new bolt as it may well pull up OK: you need a a standard 5/16" x 3" BSF bolt.

Oil is evidently getting into the combustion chamber and it's possible this is coming from a leak near the oil feed to the head. Before digging any deeper, you need to sort out the 5th head bolt and confirm there are no leaks in that area.

Have you swapped the barrel? There are some barrels out there with a porous oil way. I don't know how common this issue is, but I have one here that has been sleeved to fix this issue. You can never be sure... ;)
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Re: G5 blue smoke and plug oiled.

Postby Ozmadman » Fri Jul 19, 2019 10:27 am

Make sure that you just tighten up that bolt by feel and NOT the 35lbs ft torque setting listed for the 4 studs as that what has probably happened resulting in the stripped thread in the barrel.

I had an horrendous issue with my bolt where the barrel had been previously stripped and then heli-coiled at an angle and the re-stripped again enlarging the hole even more. Eventually the only way to solve it was to tap it out to 10mm coarse thread (and that only just about put some thread into the barrel as the hole was that bad) and make up a 10mm stud and screw the stud permanently (with some JB weld for security) into the barrel using a nut and washer to tighten down the head!! Obviously the issue now was that the hole in the head and the gasket was too small. So I drilled that out to 10mm as well and it has been perfect since. You can still just about manouever the head over the barrel still with the engine in the frame. PS don't be tempted to make that hole any deeper than it is otherwise you will come out through the open fins a tad further down the barrel
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Re: G5 blue smoke and plug oiled.

Postby vigo » Fri Jul 19, 2019 1:18 pm

Thanks fellas.No I haven't swapped the barrel. This bike has been renovated at some time but I can not say what was done, lack of paperwork. Head coming off this weekend also tutorial for my 7 year old lad.
New problem; the front wheel is not equidistant between the forks. There is 16mm (sorry metric ruler) right side and 31mm brake plate side from wheel rim to fork at base of mudguard studs. There is also evidence said studs scoring wheel rim RH side. Fitting the spindle washer makes things worse. This wheel looks fairly new could it be possible it was laced up off centre, it seems to run true and is not buckled?

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Re: G5 blue smoke and plug oiled.

Postby vigo » Sat Jul 20, 2019 4:09 pm

Ok Gents, a little intermission with the wheel thing. Head off and lots of oil inside and outside of combustion area even in exhaust pipe (I'll try and upload a pic, still learning). So lots of oil being where it shouldn't.The 5th bolt female thread doesn't seem too bad but I'll order new bolt. On undoing head bolts which were loaded correct, by me, the head came off loosely, no sticktion. I had the impression it wasn't pulled down tight despite correct torqueing. I have to suspect everything because I know this engine has been to bits at one time.
Note the head damage where the spigot sits but I don't suspect this. The barrel studs were fully home only one loose 1/4 turn.
There are washers under head barrel nuts as required I'm tempted to add another thin one or at least count threads to make sure head is pulling down properly.
Any thoughts? Oh and back tyre is now decided to not hold pressure.
20190720_110048.jpg
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