ES150 will not run right!!

[ScotBob]

Yes that’s the same bike, been few a few owners and had some improvements since then but still a work in progress.

[ScotBob]

Tried the tissue over the carb inlet and it sucks it straight in no problem, still reckon it’s main seals?

[ScotBob]

Plug colour:

[ScotBob]

Oil leak video:

Sorry won’t load file !!!

[breakwellmz]

Tried the tissue over the carb inlet and it sucks it straight in no problem, still reckon it’s main seals?

It would be difficult to start with shot main seals wouldn`t it?
Plug looks to show a weak mixture but has the colour changed from what it was?

[Blurredman]

Agreed. That is a lean plug!

[Puffs]

Removed

[ScotBob]

No I don't think it's the clutch side main seal. If it was, the plug would be wet with oil, it would smoke, and you would smell the distinct smell of gearbox oil, as I asked before. And if the seal was really gone, I'd actually be surprised it would still run, as I said.

You may want to have a look at the ignition side though. I believe these engines lubricate both their main bearings with gear oil:

The attachment 50.gif is no longer available

It looks like 2 seals, one on the inside of the bearing, one on the outside. Quite possibly the one on the outside leaks, causing oil to leak into the ignition, which causes your running issues (you have points?). Easy job, have a look.

Note: I have no experience with these engines.

I'm not sure that plug indicates a lean mixture. If the carb is in good order, and in the same setting as when it ran well, it shouldn't have changed. First sort the issue at hand, then maybe look at improving jetting.

A small vid you can upload in a zip file, if it's big use something else.

Compared to how it was in 03/18, particularly the seat & exhaust seem to be a big improvement! Though I like it better without mirrors...

Thanks for you thoughts and input; see pic below from ignition side if it is the pictured layshaft seals you are referring to, these are the first things I changed but to no avail,it’s definitely not burning gear oil and the oil leaks through the clutch rod hole in the layshaft.

[AlanJ]

Hi Bob,
According to what you found with the tissue and the fact that you do not have smoke on running, then, the main seals should be ok.
Now if you are still getting pressure in the gearbox it's coming from somewhere and if you had a broken piston ring could that exhaust pressure
give you erratic running as well as pressure in the box. The reason I am saying this is because when you did the tissue test, but the engine
is obviously not running at this point so no exhaust pressure. I must mention that I have never heard of this being a pressure problem but we
are running out of possibilities somewhat.
Wish you well Alan.

[ScotBob]

So based on the "lean" comments I have adjusted the mixture to richen it, bike still won't go right, lifted the needle a notch and no different.

In summary; bike starts easily hot and cold and ticks over, revs reasonably freely when static but will not pull under load. It will get off the line through first and second but needs a lot of revs and will not rev out, totally bogs down in third and dies in forth.

All carb components changed out for new, no different, new pattern carb fitted, no different, Mikuni carb fitted, no different, fuel tap and filters changed tank cleaned and no different. The symptoms remain the same regardless of carb fitted or mixture settings.

All ignition components changed out for new; points, condenser, coil, plug, HT leads, plug and cap, timing checked and correct; no difference.

Oil leak: Oil leaks from layshaft, oil level checked and correct, lay shaft oil seal replaced, shims checked, seal holder gasket changed and it still leaks.

Oil is literally squirting out the centre hole on the layshaft (the hole that the clutch rod passes through).

Crankcase breather checked and ok exhaust checked and not plugged.

The big question, being are the two issues linked; the bike ran fine for the first 500 miles I owned it, then one day it just cut out and the above issues commenced.

[ScotBob]

Hi Bob,
According to what you found with the tissue and the fact that you do not have smoke on running, then, the main seals should be ok.
Now if you are still getting pressure in the gearbox it's coming from somewhere and if you had a broken piston ring could that exhaust pressure
give you erratic running as well as pressure in the box. The reason I am saying this is because when you did the tissue test, but the engine
is obviously not running at this point so no exhaust pressure. I must mention that I have never heard of this being a pressure problem but we
are running out of possibilities somewhat.
Wish you well Alan.

Thanks Alan, would do no harm to pull off the barrel and have a look at the rings, as you say i'm running out of options.

[dave47]

Hi Bob,
You say the oil is coming out of the output shaft, but the other end is above the oil level and I would think protected from splashing by the clutch basket.
Are you sure there is not too much oil in the case. It should be 450ml.
It might also account for a lack of power due to drag.

[ScotBob]

So head and barrel removed, rings are intact and undamaged and the bore looks good, there is a bit of scorching on the piston.

But the bad news: the crank is off centre and gouged where it has been hitting the casing, so could be bearing failure.

[ScotBob]

Piston and bore:

[AlanJ]

Hi Bob,
Sadly looks as though you have found the problem. If you are right about the bearing, and, I suspect you are, then maybe it would be the right
time for an engine rebuild and if that is the case, and you want to go that way, then please give me a pm with your number, I may be able to help.
Stay safe Alan.