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SteveP

Stubborn Merry Tiller

As the title. It ran when I garaged it last year but now it wont run.

I have done the obvious, checked spark, compression, fresh fuel.

It will fire when I put petrol directly into the cylinder or the carb but stops very quickly. That indicates to me a fuel starvation but I am open to opinions.

Has anyone any knowledge of a Briggs&Stratton Major and can offer any advice where to go from here? Preferably without dismantling the carb.

Does any small engine expert on the forum want a service job?
Nick

Lorraine...
perlogalism

Pull the fuel line off the carb and turn the engine over. See if the fuel comes out. If not see if there's a fuel filter and replace it if there is. If not, take off the whole pipe and see if there's a blockage in that.
sean

I've no idea at all. Stubborn Merry Tiller sounds like a recalcitrant hobbit though.
vegplot

Use some carb cleaner to clear out the carb. Check seals haven't perished as can happen with pump petrol containing ethanol. Carb service kits are inexpensive and it doesn't take long to service a carb. While you at it check the float and fuel flow needle.

I've ignored your comment about taking the carb apart.
SteveP

I tried some carb cleaner in the chamber, anywhere else will require dismantling the carb. Not convinced it has a float but I am no expert. To get fuel to the carb with a float requires a fuel pump doesn't it? The carb is above the tank and fuel comes from below. maybe I need to find an exploded parts diagram.

I am very reluctant to play with the carb because I had a working Stihl brushcutter until I tried to service it. If all other suggestions don't fix it I have nothing to lose.

I was serious about anyone who is competant (and not too expensive) servicing it. The local commercial outfits charge more than it is worth.
vegplot

If you're reluctant to remove and take apart the carb then drain the tank into a container a look for debris such as rust. If you see any then is likely the carb will be blocked and will need to be dissembled. As the engine runs okay when fuel is available then you don't need to diagnose anything else unless there is missing info.

Start at the fuel tank and work you way back to the carb.

"Pulsa-jet engines can be troublesome to start from cold. Try filling the fuel tank brim full, if the engine then starts easily the fuel pump is not working properly. It may be that the tank has been dry and the pump needed priming but if the cold start problem persists the carburetor will need servicing."
SteveP

Thanks Vegplot. You are a real back saver. You deserve a medal.

Over filling it did the trick
vegplot

Thanks Vegplot. You are a real back saver. You deserve a medal.

Over filling it did the trick


You're welcome.

It's a feature of the Pulsa-Jet carb that it requires priming if it left unused or drained of fuel. This is usually done by overfilling the petrol tank to ensure the top reservoir inside the tank has fuel. It's this reservoir that feed the carb.

Under normal running conditions the card pumps fuel from the bottom of the tank to the reservoir at the top of the tank but if this runs dry then you need to fill the tank to the brim in order to fill the reservoir.
Nick

Can you advise how to get a quad bike running, please?

I like this online mechanic thing...
vegplot

Can you advise how to get a quad bike running, please?

I like this online mechanic thing...


I only 'do' old stuff. Both my motorbikes are 40+ (age and mph).
Cathryn

Can you advise how to get a quad bike running, please?

I like this online mechanic thing...

Remember that it hasn't got an automatic choke?

Of course you did, just like Jack did this morning. Smile
vegplot

Can you advise how to get a quad bike running, please?

I like this online mechanic thing...

Remember that it hasn't got an automatic choke?

Of course you did, just like Jack did this morning. Smile

You, no doubt, pointed that out to him?
Nick

Can you advise how to get a quad bike running, please?

I like this online mechanic thing...

Remember that it hasn't got an automatic choke?

Of course you did, just like Jack did this morning. Smile

Nope, it has a manual choke, which I used. It seems to flatten a battery very quickly, despite the battery being a year old, and having had no use.

It almost fires up, but not quite. I've put fresh fuel in, but not a lot. It sparks. Timing chain was an issue, but they fixed that. Could it have slipped?
vegplot

The timing chain will certainly be an issue if it wasn't put back correctly.

Assuming it was the most likely, not definitely, cause is fuel starvation. As before start at the fuel tanks and work forwards. First thing you can try is disconnect the furl line into the carb. Turn on the fuel tap. If fuel spills everywhere then you know it's not the tank, tap, or fuel line. Turn off the tap, that bit is quite important. The wary will have found a suitable container in which to catch the fuel before opening the tap.
Nick

Timing looks fine, at least the lines on the timing gear and the flywheel are in the right place.

Fuel is getting to the carb.

Battery isn't holding a charge, so, is it safe to jump from my car? Both are 12v.
vegplot

I don't know for sure to be honest but I would assume it would be okay to do so. Just be aware the cranking current of a car battery will be far higher than on a quad bike. Check all connection are sound (earth strap) and ensure both use the same grounding system (if jumpstarting fro0m another vehicle) e.g. negative earth. Nick

It worked, and with a full tank of clean petrol, it's running. There's a turns wheel which adjusts idle speed and I had to play with that a while.

So, I've been up and down the lane for ten minutes or so.

Sometimes, when belting along, the engine just falls to idle speed for a minute, and I can only limp it along in first gear. Then it back fires, and the throttle works again. Did this two or three times in a row, then runs perfectly for another five minutes before I came home.

Any thoughts what might cause a lack of revving?
dpack

it might be electrical issues.damp,dirt and ht dont mix well

try spraying all wires,plugs,things connected by wires with wd40,wipe clean and respray,leave it ten mins for the propellant to evaporate (safety first) and then see if drying it has helped.

edit,if it has electronic ignition control i cant help but if it has a mechanical system check the distributor is sparking each cylinder correctly.i assume it has more than one pot ?

if that didnt work it might be control gear issues ,check all cables ,clamps etc are adjusted correctly.try again.

does the magneto/alternator put out a steady voltage when the engine is running ?try not to get zapped by the ht ,it hurts .
Cathryn

It worked, and with a full tank of clean petrol, it's running. There's a turns wheel which adjusts idle speed and I had to play with that a while.

So, I've been up and down the lane for ten minutes or so.

Sometimes, when belting along, the engine just falls to idle speed for a minute, and I can only limp it along in first gear. Then it back fires, and the throttle works again. Did this two or three times in a row, then runs perfectly for another five minutes before I came home.

Any thoughts what might cause a lack of revving?

This might be something to do with the head gasket on the engine or drain the carburettor (but it's probably not this). The back firing and losing power happened to one of ours and it had to go into hospital as it turned out to be quite serious.
vegplot

It worked, and with a full tank of clean petrol, it's running. There's a turns wheel which adjusts idle speed and I had to play with that a while.

So, I've been up and down the lane for ten minutes or so.

Sometimes, when belting along, the engine just falls to idle speed for a minute, and I can only limp it along in first gear. Then it back fires, and the throttle works again. Did this two or three times in a row, then runs perfectly for another five minutes before I came home.

Any thoughts what might cause a lack of revving?

Back firing is a sign of poor mixture control. Run the engine hard under load then use the kill switch to cleanly cutoff the engine. Remove the plug and note the colour. Black and sooty it's too rich light grey or white too lean.

Reluctance to come off idle: Assuming it's a carb that uses a float chamber then it could be a sticking float which either causes fuel starvation or flooding. Carb cleaner may cure this as it dissolves petrol deposits that build up over time. Awkwardly it could the float not set at the right level. This involves stripping it down, cleaning carefully, and resetting. Don't advise doing this without a manual and a carb gasket set.
Nick

Black and sooty.

I'll get some cleaner. Thanks.
vegplot

Might only need a few tweaks of the mixture screw in the carb. Cathryn

You're amazing Vegplot. Smile Nick

I'll have a play with the screw on Thursday, when I return from the north.

My bet is crap in the carb, tho, it's been stood a long time. And I doubt it's been poked about in ten years, if ever. Carb is a bugger to get to, tho. Kit is only twenty notes, tho, so not a disaster.

I appreciate the help.
vegplot

You're amazing Vegplot. Smile

Embarassed
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