Almost new RobinSubaru EH035 suddenly stopped and will not restart.

[Happy Valley]

Yes, I would too. Even a "new" or "new looking" plug can fail.

When trying to diagnose an engine performance issue, installing a new plug is the most sensible and most economical first thing to do before digging into an engine looking for other causes.

You bet, eliminate the simple and obvious first. Sometimes hiccups like this, particularly on a near new, quality engine like a Robin, get over-thought in forum threads.

 

[HeadSmess]

you done just about everything...hmmm

no mention of checking valve clearances. with a 4 stroke, that needs a peek... 4-5 thou, .1 mm...

checking that the valve gear is actually working is a good idea

the ignition timing can only change if the flywheel key has sheared.

 

[Deleted Member 4613]

Maybe you can try this. Spray starting fluid directly into the carb and see what happens.
For cold engines that have never been started, this works, but I do think you have some kind of basic problem. Let us know if you find it.

 

[Oban]

Swapped the spark plug for one that was working in another engine - no luck I'm afraid.
So I'll check the valve clearances Headsmess
Chris - I found that link when searching but I'm afraid it doesn't help - I've tried it with the kill switch in and out of circuit - also i get a good spark when the switch is on and nothing when it's off - as you would expect.

It's pretty depressing having to start thinking about stripping down a brand new engine after 6 hours!
I guess I've learnt my lesson to buy locally and I could have taken it back under warranty.
If the valve clearances seem okay I'll have to bite the bullet and take it to the local engine shop to check that I haven't forgot anything obvious.
Thanks for your ideas though...

 

[Oban]

Rawly old - stripped the carb and blew through all the jets, fine mesh screen internally and external filter both totally clear. all diaphragms intact and appear to be working as they should.
Oil rich mix? I'm confused - it's a four stroke....

 

[rawly old]

Dry plug, if the carb's not wet the 1st thing to check is the filter
before tearin into carb. Them little filters can swell shut & clog for
not good reason even when new. If that ain't it maybe a clogged
jet or sticky diaphram?

 

[rawly old]

Geez, I don't know what to tell ya then. sorry, realized 4 stroke and deleted,
not in time tho. Who'd ya buy it from; got a warranty?

 

[darwin]

When you press the primer bulb does it clear all the air out of the fuel lines and pump fuel through the return line? You should see hear feel it doing so. Could be your diaphram popped, only takes a lil slit to render it useless.

 

[Oban]

The primer bulb fills up with fuel and pumps it via the return line.
There is good flow through the main filter, I checked it before stripping the carb.
The only reason I stripped the carb is that when the engine stopped it was far too sudden to be a blocking filter so I thought that it might have been an instaneous blockage of one of the jets - but they were all totally clear.
Something doesn't add up and I don't know if I'm missing something glaringly obvious.
It's going for a second opinion soon.

It was bought from Staton as part of a kit with their gearbox and crankshaft kit. It was cheaper and less hassle to do that than buy one here in Scotland.
I've no doubt it does have a warranty in America but it just isn't worth the cost or hassle of sending it back over.

 

[motorbikemike45]

Your warrentee is not with the company you purchased the engine from(Staton), but with the manufacturer, Subaru-Robin. Check with Robin UK, or whatever the UK importer is called and see if they won't honor the warantee. I know Robin-America would honor the warantee, regardless of where the engine is used, if only for the good will of the name and because Subaru in Japan would want them to. Shipping costs would be high, of course, so it might be cheaper to have a local shop familiar with Walbro carbs and Robin engines check it out first. If you can find your local Subaru Robin dealer, check and see if they won't honor the warantee. I'm fairly certain they will, regardless of where it was purchased.