OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions on Greenfield Ride On Mower Frames Fastcut Wont Start

Hi,

First time posting so please be HARD.. I mean Gentle

So its a 17.5hp Briggs that just died whilst i was mowing
There is a known issue with the battery charging system I need to look at but I've been jump starting it the last few times until get time to do some fault finding on it but looks like I have to make the time now this weekend to work on it.

What I've checked so far:
It has spark (plug against block check)
It has fuel in the carby bowl
Oil is clean and good level

I'm thinking it must be electrical somewhere but am having trouble finding a manual

Any suggestions on what to test with some values or a pointer in the right direction to a manual.

I'm really hoping its something simple as the wife has just given up work to spend more time with our kids so money is tight

Thanks

This may give you some pointers as it could be valves
http://www.ssbtractor.com/wwwboard/view_all.cgi?bd=lawn&msg=3

Thanks NormK but I'm not sure what that has to do with my problem?

Righto, first things first.

For us to find the manual, we need the Model, Type and Code numbers off the engine, so that we know exactly what we're dealing with.

When you say 'won't start', does that mean that it still cranks over OK; but won't fire at all, or fires sometimes but won't keep running?

Don't know why it pulled up the 20hp one, the page I was viewing was the 17.5. If you google 17.5 Briggs and Stratton you will find one on the Craftsman with 17.5 B&S and that has a fair bit of info as to why they won't start. And if you have spark that rules out electrical apart from a spark plug

I'll get the numbers in the morning

Yeah it cranks over fine but won't fire and continue firing/running.. it fires very occasionally but only for a second and then back to just cranking over

Thanks for the reply

I'm going to grab a new spark plug for it in the morning but it sparks quite well but is definitely worth it for the potential

If an OHV 17.5 it would a 310000 series.

If several good possibilities. But first changing the plug with a known good plug; new don't always mean good. Plug can fire quite well out of the engine and fail under compression load.

You may have an ACR problem too since you have been having to boost the battery to start or you simply have trash in the carburetor's fuel bowl blocking the main jet as it is sucked up as the engine starts.

A couple notes here on these engines. They prone to both the ACR on the camshaft to breaking and for the head gasket blowing between the cylinder and the push rod galley. The first will cause very hard to turn over condition as the engine is at full compression and starter simply don't have enough power due to voltage drop. Most operators simply think it is a bad battery, a charging problem or bad starter. The later will cause engine to use excessive oil without even smoking resulting a condition where you have no oil and breaking the piston connecting rod.

I don't think you got a broken rod but may still a blown head gasket as it will hit. If you can do a leak down test to verify that all is well in that respect as preventative maintenance check.

AVB, this motor was running and died, this to me indicates a mechanical failure if spark is good. I'm thinking cam, not fuel because it was running fine and just stopped

NormK,

It still can be spark related as I have seen plugs to fail under compression and still fire outside the engine when not under compression. I even had one compressor that would run and idle when started but quit as soon as the compressor was to again build up the tank pressure. Simply would not run if the engine was needed at 90psi tank pressure load. I could drain the tank pressure and engine would again build the tank to the cutoff point and return to idle. It would idle all day unless it the a pressure build up needed. Any time an engine is under load the compression load is even higher.

When comes plugs misfiring under compression some strange things can happen. I had one Husqvarna backpack blower last Spring where the operator swore the connecting rod was the problem as knocked so bad above idle speed. It turn out to be a failing plug.

Even Ignition coils can fail the same way just not as often. Most either works or not but I have some very coil problems too. With one that would set fire to air filter on a Homelite Chainsaw. I also had Husqvarna 570 just a few month ago to run great when first started to only go bonkers later doing all kinds things including backfiring out the carb and shooting flames out the muffler.

Now if this is a L-head (I think you guys called side valves) then a valve not closing completely can cause the described problem as there can be an overactive ACR.

So gather what information I can of the machine.

The glorious machine


Its a 18.5hp sorry




I can't find what exact "Evolution" model it is but here is the serial in case that helps



To do:
I'll give the bowl a good clean
Try a new plug

To do but need advise:
How do I test the head gasket without a compression tester ?
Not sure on how to test the ACR but I don't think that is the issue as it cranks just the same as before

Appreciate the assistance

Hi Freakn,

The engine's Model, Type, & Code should be etched on the silver rocker cover circled in the picture.

Thanks LRT

Model: 310777 0
Type: 11 B1
Code: 1107277D

or 310777 0 11 B1 1107277D

Small update:

Fuel system cleaned & checked - filter ok, bowl cleaned (no sign's of buildup) and tanked checked

Intake removed and can see 1 valve working as it should (cranking by hand slowly)

Engine oil drained & checked - oil in ok condition and no visible metal filings or fragments from mechanical failure

Replaced spark plug - still just fires once and then just keeps turning over

No obvious signs of a head gasket failure - no oil or carbon build up around the gaskets


Next:

Reassemble and see if it starts

Then continue with fault finding

Is it safe to run these engines for sort periods idling without the cowling to duct the air cooling system?

First you can safely run the engine for short for test purposes.

If head is blown as I describe you would not see any oil or carbon build up as it is an internal problem. There is one tell tale sign you might see and that it is oil in the air cleaner entry at the carburetor. Not always present fence the leak down test recommendation.

Here is a picture of what I described.

Compression test completed and siting at 100psi

Now this got me scratching my head.

Also could that be a 310777-0112-E1 when comes to the engine numbers?

Sorry it's 31Q777-0112-B1

Update:

It's Alive

Turns out it was the little solenoid fuel cut off that goes in the bottom of the bowl... well with it removed and the hole capped the mower run's

Haven't given it a full work out as all the cooling system cowling is off but will put everything 100% back together and give her a run in the morning.. it's a hot'n'humid north QLD saturday so it's beer time

Well I've been waiting for a day that I could pick up a cheap compression tester and today was the day - got it for next time plus a spare plug

Still need to work out the battery issue though, fairly sure its the solenoid but am unsure as to how to fault test it... would appreciate some guidance on that issue

Thanks for all the suggestions and help so far.. would love a link to a workshop manual or full electrical schematic

Hi Freakn,

Here is the link to the workshop manual: Single Cylinder OHV
Air-Cooled Engines

Here is the link to the parts manual: IPL 31Q700 Model Series

How to test the solenoid is covered in the workshop manual on chapter 2 (pages 26-27).

That's awesome LRT

Thank you VERY much

My pleasure Freakn. I'm glad to be of help. Thanks for letting me know.

And thanks for letting us know the solution Freakn. This can help others. Things I check when cleaning carburetors and rebuilding but forget to mention as it an automatic thing here to check.