On the two carb pictures though? One quadrant looks much bigger than the other from here.
John
John
Hayter 13/30 ride on lawnmower - linkages
- Thread starter Hobsini
- Start date
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Ah I see , or I didn't see more like, the pics you were comparing.On the two carb pictures though? One quadrant looks much bigger than the other from here.
John
I'll have to look on something with a larger screen than my phone for me to see
Hi, finally returning to this and have resolved most issues. However, the engine is surging or not running smoothly at least. I’ve tried adjust carburettor, checked fuel system and spark plug - also removed engine casing to clear out any debris. I have a new carb but the same problem exists with the old one as well (plus other issues). Any ideas what to check next?
I guess you have sorted the governor to carb linkage out, and you are happy with it?
Two questions if I may.....
Does the engine tick over steadily when the throttle is closed?
Have you tried a new fuel filter?
John
Two questions if I may.....
Does the engine tick over steadily when the throttle is closed?
Have you tried a new fuel filter?
John
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Yes, I believe the linkages are now correct based on my research. Fuel filter is new as well. Engine does not tick over steadily when throttle is closed though. It either dies or continues to surge at lower revs. With old carb on it overheats and backfires as well!
With new carb I have tried adjusting carb settings but this doesn’t seem to make much difference. Wondering whether it could be the fuel/air mixture needle on the new carb. Thought about swapping with that from the old carb - just to test- but not sure how to remove that (as it has a limiter on). Could the problem be spark plug or oil related? Run out of ideas for what to try next.
With new carb I have tried adjusting carb settings but this doesn’t seem to make much difference. Wondering whether it could be the fuel/air mixture needle on the new carb. Thought about swapping with that from the old carb - just to test- but not sure how to remove that (as it has a limiter on). Could the problem be spark plug or oil related? Run out of ideas for what to try next.
The cause of any engine spitting back through the carburettor is a weak mixture. This is due to a blockage (however slight) or an incorrect main jet size. Faulty gaskets may also cause this but it's less likely.
The spark plug can be a culprit - they may look perfect but can fault....look for a white ring around the centre electrode but pop a new one in anyway.
Oil is not related to this issue, but obviously it's level should be correct.
Adjust the tickover screw so the engine is running just a little faster than you would normally expect, and at this point adjust the pilot mixture so the engine hopefully runs sweetly.
If you can give us a pic of the 'limiter' you refer to please?
John
The spark plug can be a culprit - they may look perfect but can fault....look for a white ring around the centre electrode but pop a new one in anyway.
Oil is not related to this issue, but obviously it's level should be correct.
Adjust the tickover screw so the engine is running just a little faster than you would normally expect, and at this point adjust the pilot mixture so the engine hopefully runs sweetly.
If you can give us a pic of the 'limiter' you refer to please?
John
Still struggling with this. Have replaced spark plug, fuel hose and filter and have a new and old carburettor. Still have a problem getting it to run smoothly (with either carb). It starts ok and surges a little at high revs and surges more and then stalls at low revs. I’ve tried adjusting the fuel mix and idle on the new carb but problem persists. On old carb I can only adjust the idle as fuel mix adjustment has limiter on and I am not sure how to remove that (pic of this in earlier post). Either I have a similar problem with both carbs or the problem is elsewhere. Maybe the governor and linkages aren’t right after all or could it be something else?
While making adjustments it would also backfire and also stall at times. How slight should the adjustments to the fuel mix and idle be as I made quite significant (e.g. half turn) adjustments each time. One issue with this process was I couldn’t really do it while the engine was idling as it would just stall at low revs.
New carb is a generic (non Walbro) replacement but more recently I’ve gone back to trying to resolve the issues with the original carb. I’ve stripped this down as much as possible but had trouble removing all the pieces/parts so it wasn’t comprehensive. Seems odd that it’s the same-ish problem with both carbs though.
While making adjustments it would also backfire and also stall at times. How slight should the adjustments to the fuel mix and idle be as I made quite significant (e.g. half turn) adjustments each time. One issue with this process was I couldn’t really do it while the engine was idling as it would just stall at low revs.
New carb is a generic (non Walbro) replacement but more recently I’ve gone back to trying to resolve the issues with the original carb. I’ve stripped this down as much as possible but had trouble removing all the pieces/parts so it wasn’t comprehensive. Seems odd that it’s the same-ish problem with both carbs though.
Sorry this is still giving you grief!
Original carb.....the black limiter prevents you from excess adjustment of the pilot, or slow running, mixture. Usually the cap can be prised off so you can adjust further - in fact the thing needs to be out completely so the fine drillings beneath it can be blown clear.
If the machine backfires (or rather, chuffs back through the air cleaner) then the mixture is too weak. There are no other fuel mixture adjustments.
When I am trying to tune the pilot mixture I keep the idle speed a little high to prevent stalling, and then altering the idle mixture to suit....maybe an eighth of a turn at a time, and then giving the engine a rev in between adjustments.
I think I'd concentrate on the original carb for a while.....get that black cap off and unscrew the needle completely after counting the turns out. This will allow a proper clean.
Coming back to your post #6, second pic with the red circle......see that small hole to the right of the main carb venturi? That's where the pilot air comes from and it must be clear.
John
Original carb.....the black limiter prevents you from excess adjustment of the pilot, or slow running, mixture. Usually the cap can be prised off so you can adjust further - in fact the thing needs to be out completely so the fine drillings beneath it can be blown clear.
If the machine backfires (or rather, chuffs back through the air cleaner) then the mixture is too weak. There are no other fuel mixture adjustments.
When I am trying to tune the pilot mixture I keep the idle speed a little high to prevent stalling, and then altering the idle mixture to suit....maybe an eighth of a turn at a time, and then giving the engine a rev in between adjustments.
I think I'd concentrate on the original carb for a while.....get that black cap off and unscrew the needle completely after counting the turns out. This will allow a proper clean.
Coming back to your post #6, second pic with the red circle......see that small hole to the right of the main carb venturi? That's where the pilot air comes from and it must be clear.
John
Thanks - will try removing the limiter next and retuning.
Next question....when you park the machine up and leave the fuel turned on - does it flood with petrol?
John
John
Not sure. I’ve not really been using it as it doesn’t run well at all - so, it’s been parked the whole time while I’ve been working on it. If it’s parked and running, where would it flood as I’ll check this as well.
On a typical Briggs carb of this size, there is a small red rubber seal above the needle valve in the float chamber that occasionally gets lost or lets fuel by due to wear.
If this happens the engine may fill up with fuel or it may drip petrol from the connection between carb and air filter flange.
Very strange you are getting the same symptoms with two carbs, but of course we don't know if the jet sizes on the new carb are the same size as the old....the size used to be stamped on but I don't think they are any more.
John
If this happens the engine may fill up with fuel or it may drip petrol from the connection between carb and air filter flange.
Very strange you are getting the same symptoms with two carbs, but of course we don't know if the jet sizes on the new carb are the same size as the old....the size used to be stamped on but I don't think they are any more.
John
Scratching the brain cell once more....
How do you feel about popping the flywheel off?
The reason I'm asking - many engines have a tendency to shear their flywheel key......I've done a dozen or so. Usually the ignition timing goes completely to hell and the thing won't start at all, but if it's just slipped a midgies - who knows?
At least it would rule it out of the equation because we haven't found the problem yet!
John
How do you feel about popping the flywheel off?
The reason I'm asking - many engines have a tendency to shear their flywheel key......I've done a dozen or so. Usually the ignition timing goes completely to hell and the thing won't start at all, but if it's just slipped a midgies - who knows?
At least it would rule it out of the equation because we haven't found the problem yet!
John
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