Hi Aussie, Timing is fixed so problem is still in the carby. If it will fire for a second it tells me it hasn't been straight fueled so carby is the issue
Hi Aussie compression does not indicate it hasn't been straight fueled, a look in through the exhaust port and if any scoring on the piston is a dead giveaway. If not it is a carby problem. Another way to test for carby problem is to put a puff of starter fluid down the plug hole and if it fires for a second that proves carby
I should add, there's a definite 'bang' , usually I think from the muffler but occasionally from the intake. Also,. after quite a length of time trying to start, the muffler is hot to touch, but also the intake hose is warm which I wouldn't have expected.
It's not possible for this electronic ignition setup to be incompatible with the coil or something is it?
I just use a spray bottle with 2 stoke mix but starter fluid works well when sprayed into the air filter housing with the air filter element removed , some times 2 strokes won't run properly without the snorkel and filter housing installed .
I've had a 2 stroke backfire when the spark is weak ,usually a bad spark plug or coil.
It might be worth filing the points and putting them back in so you can set the timing if the coil plate is adjustable some have adjustment and some don't ,then once the motor is running fit the module.
Might be easier to remove the starter and put a socket extension in a drill then use the drill with a socket to start the mower.
It can only be one of 3 things stopping it running if you have 2 of the 3 right ,1 spark problem ,2 fuel problem ,3 mechanical problem.
If the crankcase seals are leaking it will be hard to start.
Hi Max, What I seem to find is if I put starter fluid through the carby and I get nothing and then if I put fluid down the plug hole and it fires then I am pretty sure it is a crank seal
Yes there are a few ways to check for leaks without doing a Vac or pressure test and I'm sure you've done these tests below.
You get different results depending on how bad the seals are leaking ,sometimes I just put about 10 squirts of oil into the spark plug hole then put the plug back in ,then turn the motor over a few times ,after you let the mower sit for a couple days you can see oil running down the crankshaft.
If you know the carby is good but the motor is running too fast you know there has to be air leaking into the motor also when a motor runs and you turn the fuel tap off and the motor revs up before cutting out.
Sliding a 1 to 2 thou feeler gauge between the crank and the seal will be a loose fit when the seals are worn and hardened from age.
You can start a 2 stroke then spray starter fluid at the seal and if the revs change the seal is leaking.
I've had a few 2 strokes that will only rev out if you almost completely crush the snorkel tube when running ,must be giving the engine more fuel to compensate for the extra air leaking into the engine.
Automotive seals generally stay soft for about 10 years,so as we know the seals are fairly suspect on old mowers etc.
Good afternoon all, life got in the way and got back to this last weekend.
I purchased a known good second hand coil, points, condenser and fitted these, and an all-metal G3 carby that was also known good and cleaned/seals replaced.
Second pull she fired and 3rd pull she started.
150 square metres of mowing later, I think we can safely say she's running!
Reel and bottom blade could obviously use a grind, I think the drive clutch cable needs replacement and the cut isn't 'square' but surprisingly good for a machine I don't expect has mown for the best part of 10 years!
My lawn has been neglected too over the last 6 months and isn't the best canvas to work with...
I don't suppose anyone knows who would do a reel sharpen/grind in the Wagga area?
