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EMGO gasket set?

4K views 19 replies 8 participants last post by  StuartMac 
#1 ·
My Bonneville has a few oil leaks as I guess can be expected. I'm planning on getting started with the ones that are easily accessible, primary, gearbox etc, and I think it'll work out cheaper to just buy a full engine gasket set at this point. Is EMGO the one to go for or are there better options?

There's also a reasonable amount of oil weeping from the cylinder block to crankcase join. That certainly looks to be a bigger job and I think I'll just need to keep an eye on it for now. I don't have any long rides planned, and I'm going to just slowly work my way in to fixing issues on the bike. Any expert advice on this one other than pulling the engine?
 
#3 ·
Hi,

My Bonneville has a few oil leaks as I guess can be expected. I'm planning on getting started with the ones that are easily accessible, primary, gearbox etc, and I think it'll work out cheaper to just buy a full engine gasket set at this point. Is EMGO the one to go for or are there better options?
@johntioc is boss of wholesaler Coventry Spares. He might be able to advise, and/or I suspect he supplies Rabers, who are a lo-oo-on-ng time Triumph dealer. John is also the maker of CovSeal gaskets.

weeping from the cylinder block to crankcase join.
While it isn't a quick job, the top end can be stripped to the top of the crankcases without "pulling the engine"(?). Problem you might then find is the leak is due to the crankcase mouth not being level across both crankcase halves ... :(

Hth.

Regards,
 
#4 ·
I can see the Cov Seal gaskets for the rocker box (only part that's not leaking...) but I don't see any full engine sets. I'm guessing this type of composite gasket wouldn't be used in a lot of places anyway.

Do people generally re-use gaskets when opening up the primary or gearbox covers, or removing carbs? I realise the head gasket must be renewed if it's touched, but what about these other ancillary gaskets?
 
#10 ·
Hi,

Do people generally re-use gaskets when opening up the primary or gearbox covers, or removing carbs?
If you grease 'paper' gaskets on both sides, they won't stick to the ally, they'll just peel off; also helps with fitting when the surface is vertical. :thumb
Imho, reuse or not depends on the :gah quotient to redo if a reused gasket leaks. So I don't reuse, say, primary gaskets but I do reuse, say, rocker cover ones - the rocker cover ones I only grease on the 'box side', so they do stick to, and come off with, the lid. :thumb

I realise the head gasket must be renewed if it's touched,
Not if you use a copper one, they can be annealed and reused. In addition to head gaskets, I always use copper cylinder base and rocker-box base gaskets. Haven't bought new ones of these in decades.

Otoh, legendary triple factory race mechanic Steve Brown never used/uses gaskets except a head gasket, he always said gaskets double the number of places a leak can start; :) he lapped/laps each joint surface smooth when building engines.

Hth.

Regards,
 
#6 ·
Whatever gaskets you replace, when you do it, use Honda Bond on both sides of the gasket prior to instaling. Available on Amazon for about $10. It is THE single best sealant I have ever used. Goey as it gets, so wear gloves, but you'll never have a leak where you use it.
 
#7 · (Edited)
Great, Hondabond will be ordered with the gaskets. Any advice on which gaskets I can use the Hondabond on both sides of? For example I'm guessing I want to be able to remove and refit the primary, so only use on one side?

I'm a little curious after doing some more reading whether there's pressure build up in the crankcase that's causing more oil to get pushed out here. It seems like a potential cause. I guess the next thing to do is take apart the breather under the bike and check it's clean?

Is there any additional benefit to adding a PCV reed valve instead of the factory breather? Am I right in thinking this causes a vacuum in the crankcase when the piston goes up?
 
#9 ·
Use Blue Hylomar and the gaskets will be re-usable most times but sometimes they might break after a couple of dismantlings.The copper head gasket can be re-used many times if you give it the annealing treatment each time.Just bear in mind that the primary can be sealed with silicone instant gasket with no paper gasket at all.I prefer not to use silicone on engine gaskets though where the silicone might get into the oil flow.
Dont take that bike apart too much in the early days of ownership.Faults might happen and you might wonder which alteration caused the fault.
Rome was not built in a day as they say,but a Triumph was bodged together over many years.Each owner busting another bit each time.
 
#13 ·
Just to be clear on Honda Bond, I don't think it is intended for head gasket use! Probably not valve covers either if they are rubber.

And as said above, don't start taking things apart if they aren't leaking. No need to be hasty. Similar to my next project, I am having to practice patience for my next oil change before I pull my case covers and powder coat them black. :)
 
#17 ·
Hi,


While you can get copper gaskets in varying thicknesses for certain applications (e.g. triple rocker-box base gaskets), the cylinder base gaskets I have seem hardly thicker than the paper ones. So any c.r. change is minimal and, even if it does, it's a reduction rather than an increase.

I've put in an order for one of the reed PCV valves now too. I don't know that it's the issue, but it seems worth making sure that the leak isn't being caused by pressure build up in the crank case before I start looking at that gasket.
Before fitting expensive farkles, have you checked if the standard timed breather's working? If your bike has the standard rubber hose to a 'y'-shaped junction in front of the battery, just disconnect the engine breather hose from the 'y' and feel the pressure out of it when the engine's running on your hand. If you feel it intermittently blowing and not sucking, the timed breather's :thumb

If the standard timed breather doesn't suck, a PCV is as much use as a chocolate fireguard? Then the only way internal pressure can be causing oil leaks is the timed breather can't evacuate the internal pressure - perhaps because it's being increased by something like compression blowing past the piston rings? Also something a PCV can't fix?

Hth.

Regards,
 
#18 ·
The only gaskets I use are the head gasket and the thick gasket on the primary cover...The rocker boxes and cylinder base gets Loctitie 518....This may or may not work for you..... However, on my dual engine race bike I'm using Covseal rocker gaskets to try them out....had the boxes off a few times and the gaskets still seal at least for the short duration racing....
It's been my observation over the years that riders who use a lot of throttle before the engine is fully warmed up suffer from more oil leaks and problem in general...
 
#19 ·
Thanks guys. StuartMac you bring up some good points there.

I've just checked the breather at that T-junction and it seems that I can feel it blowing and sucking - so this would suggest the timed breather maybe isn't working or isn't fitted?

There's also an amount of emulsified oil that's coming out of the breather pipe. I'm guessing it's been trapped down in the bottom at the lowest point in the pipe. I've traced the pipe back down to the engine in the hope I could pull it off and clean it, but it goes away up behind the primary casing. If anyone has tips on how to clean this pipe that would be helpful!

Out of interest I also did a compression test, because the bike is misfiring a little at idle even when warm. The readings were 120PSI and 125PSI. Seems a little on the low side. It could be that the compression was lowered when the engine was rebuild by the PO.
 
#20 ·
Hi,

checked the breather at that T-junction and it seems that I can feel it blowing and sucking - so this would suggest the timed breather maybe isn't working or isn't fitted?
:nod So a PCV might be worthwhile on the crankcase breather, although that probably means you need to run two separate breather pipes - crankcase breather with PCV, oil tank without, or you risk the crankcase simply blowing and sucking through the oil tank?

There's also an amount of emulsified oil that's coming out of the breather pipe. I'm guessing it's been trapped down in the bottom at the lowest point in the pipe. I've traced the pipe back down to the engine in the hope I could pull it off and clean it, but it goes away up behind the primary casing.
Mmmm ... up by the gearbox sprocket. To clean the crankcase breather pipe, now it's disconnected from the 'y', tie a piece of string to that end, pull down the pipe and put it in a bowl, oil drain tank, etc. Run the engine to blow out the emulsified oil, reattach the string, pull the pipe back into place and reattach it to the 'y', or a new piece of pipe to the new PCV.

I also did a compression test,
The readings were 120PSI and 125PSI.
Low compression won't make it misfire; if it did, infernal confusion engines would never have got started. :) And extrapolating compression ratio from actual compression readings is meaningless - on that basis, people who read 150 psi have higher than 10:1 compression. :eek: 120/125 is good and the two readings are close. :thumb

Hth.

Regards,
 
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