OutdoorKing Repair Forum Forums Finding and Swapping Wanted G3 carby

Tiger,

Replace the bottom seal and your problems should be solved.

Bruce, the carby is still leaking badly so I assume that's a separate problem. Any other tests I can do to confirm that the bottom seal is faulty? This seems to contradict Tomo's earlier suggestion that the crankcase compression was ok (or can it still be ok with a bad seal?) Also is the process the same as for changing a seal on a Powertorque?

Have taken a photo of the bottom seal, no dampness or deformity that I can see. Tried to get the boss off but no luck, seems I need a 2 jaw puller, only have a 3 jaw. Will get a 3 jaw soon or is there another way?

i think your crank case seals are okay, if you have a wet plug the crankcase is fine , your bottom seal looks quiet healthy , your rings may be worn out and only sealing with extra fluid. but i think you can rule out crankcase compression. you could remove your cylinder and inspect them. gaskets are still easy to get or make

You can get the boss off without a pulley. Put it on a hard metal surface ie a vice. Then smack it with a hammer a few times. If it doesn't come off turn it around and smack again keep doing this it will come off. Just don't smack it that hard that damage could be done. Then get a screw driver and just touch the inside of the seal if its soft and flexes great if its hard and doesn't move no good replace. It may due to sitting and not be leaking yet but has enough to allow a lack of compression. To check top seal you would have to take off flywheel and ignition. Now you said it had spark just have a look at it when it sparks and see what the colour of the spark is to see,whether it is a yellow/orange colour or blue spark.

Thanks Blumbly, have poked at the seal as best I can with the boss on and it feels soft, can't see any liquid around there but it was night. Spark is definitely blueish.
Think I may have resolved the carby issue ie it no longer leaks, I had to do the screws holding it together very tight, I tried to fire up the mower this morning, after a few pulls there were some explosions/smoke and the chug, chug, chug so the mower wants to start. I'm now thinking I'll address the compression, anyone know what ring size to get for the Mayfair Deluxe? Also Blumbly, to get the boss off do you need to take the engine out of the mower to stick in a vice? In the process of looking at the carby again, the throttle switch has no effect on the butterfly valve, how can I fix this?

It is easier to get the boss off with motor off the base,unless you can get some kind of hard steel under it like a dollie,but is easier off. This one should have a metal cable inside a coil like tube. The cable inside most likely has a kink in it. It can be fixed you just have to find the kimk and using a pair of pliers to straighten it as best you can. This may well be the problem you have as if you can't adjust the accelerator then the carby can't give the engine the right amout of fuel it needs to run.

You are right about it having a metal cable inside a tube. The cable moves the governor part ok but it has no effect on the butterfly valve. So if I move the governor by hand the butterfly valve opens and closes, but the throttle has no effect. This happened before and I tightened it somehow by screwing the plastic serrated wheel a bit but now that doesn't seem to work.

It does sound like their is something funny there as where the cable connects to (should be a L sharped picece) that connects to an arm which should make the butterfly move. When when the engine is running the wind vein helps control that by the air coming from the flywheel.

This whole experience with this mower has been funny but on the positive side I have learnt a lot. If I hadn't invested so many hours in this I would have given up long ago. Would it help if I took some close-up photos of the governor mechanism?

It could. Also underneath that part of the carby you will see a plate with two Phillips head screws take that plate off and in there there should be two gears. One full cog and one half cog. Just check and make sure all the teeth are still good and workable. As they are only plastic cogs. You proberly will see some wear but hopefully not to bad.

Ring size is anyone's guess tiger its 125cc
but it may have been rebored during its life,
best size indicator is to dismantle
and inspect

Have got some photos of the governor set-up. The gears are intact, I fiddled with the governor and now I have got the throttle cable adjusting the butterfly valve but the governor vane no longer adjusts the butterfly valve - I cannot get it so that both the throttle cable and the governor vane adjust the butterfly valve, it's either one or the other it seems. Photos show throttle on off and then at full speed.
I had another look at the bottom seal, definitely no leakage there and I've done a compression test by taking out the decompressor and replacing it with a spark plug, i forgot to cover the decompressor inlet into the engine but recorded 72 psi dry. I then put some oil into the spark plug hole and recorded 78 psi, I guess that means the rings are worn. Had a look through the muffler hole and the top ring has a bit more movement than the bottom one. They're both shiny and without the decompressor the starter cord is difficult to pull, I'd thought that meant that there was enough compression to get it started. Last week the mower started with the help of "Start you bastard" but now nothing starts it. How has it lost its compression so quickly?

hey !
70 - 78 psi doesnt sound that bad for a small victa motor , sounds like your issue is flooding more than anything else .
starting to wonder if your ignition timing is still a little out ?

That's what i thought too, i've started mowers with around 60 psi before.
What are the main symptoms of flooding as i thought i had solved that?
If ignition is out, why did it start and run last week?

okay we will rule out compression, ignition. for now .

so if you attempt to start in the normal way with no fuel or start ya bastard down the plug hole does the spark plug get wet ? is the spark plug a known working plug it may be failing under pressure .

Same spark plug that i used last week when the mower ran, i did also use one from another mower that i know works.

there is a chance that the jet in the carb is off a 160cc - causing the flooding from memory the jets look the same ....
ive come across flooding with float level you can bend the fork that holds the needle slightly so the float shuts the fuel off slightly earlier - this has worked well in the past and worth a try if fuel was over flowing from the bowl this should also rectify the overflowing

Don't know about the wrong jet because the mower ran last week. Did try bending the fork but it had no effect but that maybe because i didnt have the screws holding the carby tight enough causing a leak where the gasket was. Tomo does it sound as though there is still flooding?

the wet plug suggests that there is still some issue in the fuel system you mentioned in a previous post that the needle was seating and not leaking .

i had a later victa 2 stroke had compression spark and fuel and still wouldn't go , replaced rings and it ran like new , then ive had one with jammed rings and no compression that ran like new.
they can do odd things .

might be worth pulling the cylinder off and checking out the rings , if the piston is still standard 125cc i have a set of standard rings i can send you with the rubber hose.

Ok thanks, will have a look tomorrow and let you know. Just to clarify, plug should be dry, i thought that it had to be slighly wet to show that petrol was reaching the engine?

Damp but not wet

I know this may sound silly but you don't have to much oil mixed with fuel? I purchase a mower last year that somebody had just filled it up with oil. They thought that the name self mix was all the mower needed. So eventually the fuel tank just filled with oil,no petrol at all. If only you were closer as it doesn't sound like their is much wrong with it. I don't think your timing is wrong as you said it ran.

Thanks for clearing that up Tomo, fine line between damp and wet. I've started thinking, could the timing be out, I'm getting a nice blue spark but maybe the points have moved a bit?
I've got compression, got spark, got fresh petrol, only thing I haven't checked since last week was the points. The spluttering makes me now suspect the timing.

It ran last week but since opening up the carby I've had problems, also yanked on the cord pretty hard so maybe the timing has become maladjusted. I have a special mixing container, definitely 25 to 1 so proportion is right. I know it's close and that's what's frustrating about this but appreciate your solution, guess it's a process of elimination now.

yep process of elimination !
if it splutters and pop's but doesnt run points could have moved , popping and spluttering can also be a symptom of rings also

Checked and slightly adjusted the points, mower still splutters and pops with blue smoke, guess it's time to change rings.

Tiger,

Check the condenser because sometimes under load they break down.

Condenser looks clean and still getting blue spark, how do you know when they've broken down?

Have again tested the mower this morning. The mower fires up but dies a few seconds later. I put in an old Champion spark plug, the mower definitely ran better, it reached something resembling full revs but died a few seconds later. This all happened with another spark plug sitting in the decompressor hole. Best result so far but still won't continue running. This was all getting too hard for my arm so I put the decompressor unit back in where it's suppose to go and the mower still continued to fire up but didn't sound as strong with its revs. I think that it no longer floods and if it does, it's not as bad but why does the mower fire up and then die repeatedly?