I have a B&S Quantum engine that i just service, drained the oil, replaced the plug, filled with new, started and run fine, then conked out with a bit of smoke. Noticed no oil. Look under to find missing drain plug, one of those plugs with the 3/4" socket connector.
I remember tightening it up, but i guess it came loose. Is this normal? should I be using locktite or is that stuff no good around oil/fuel? In the past, never had an issue with it coming loose and making its escape .
Also, any tips on how to fix small cracks in a plastic fuel tank? Even though they're closer to the top of the fill line, and I fill below them, somehow they still leak fuel . Perhaps fill in the cracks with epoxy, or superglue ??
Last edited by Bruce; 08/06/1807:34 AM. Reason: Updated images
Hi Widget, from memory the fix for the plastic petrol tanks is nail polish, can't guarantee it but have heard it works. As for the motor, doesn't sound good the way it stopped, no oil will do that.Plug should not come loose if it is done up properly
Sump plug is a tapered thread to stop the plug disappearing inside the engine..... I've had success with a heat gun "welding" the joint closed.... good luck
Well hate to say this but if it die while running you probably toasted the engine. Without oil the aluminum starts to overheat, melt, and transfer to steel moving especially the rod to crankshaft journal leading to the rod breaking; sometimes sending it thru the crankcase. Since the engine has ran without oil a tear down is in order to check the rod/crankshaft journal for this transfer. Once this transfer starts it only gets worse unless cleaned and repaired. If it is there then a new rod needs installing and the crankshaft needs cleaning.
As for the oil plug as Dieselboy said it is a taper (pipe) thread. Now new plugs do come with red Loctite type sealer but I would not use it after the initial coating is worn off as I have seen it to seize completely preventing plug removal. I had a Cat pressure pump that I was rebuilding and the service manual spec'd it on the check valve plug caps. It seized before I seated the cap and I almost didn't did the cap back off. It using a die grinder to re-cut a new hex on the cap even me using a torch to heat the joint.
Those tanks are HDPE plastic and welding it is the only method that works permanently. NO open flame or sparks permitted as explosion is possible. Here I use a soldering iron with all the solder removed and the same HDPE plastic as a filler material. This is after the tank is thoroughly cleaner and dried. The reason I use a soldering iron as I can get very deep welds where the hot air method only penetrates slightly leading fairly quick failures.
Still the best option is replacement and by no way I recommend anyone doing this type of repair without the needed experience or supervision.
As for changing the oil in these small engines I have changed over to using an pneumatic (air operated) vacuum oil extractor. This was mainly because I was getting in engines without drain plugs or they were inaccessible. Not easy turn garden tillers on their side or upside down. There is added benefit for me as it is a lot less messy plus I can easily fill jugs to take the recycling drop point while I am grocery shopping on the weekends. I guilty of having slip an new engine 90 degrees making the plug inaccessible myself as there was no way adding an access point.
Anyone know what the thread specs are of the drain plug? and if you can buy tapered bolts to fit? I had a look at the price of a replacement drain plug, and tbh it was a bit much, so was just gonna replace with a bolt and washer.
As for the plastic tank, I might try and patch/repair it rather than buy a new tank. This mower, though I picked it up Free, still works well, but didn't want to spend money on it (have other mowers too). I'll give the mail polish a try, see how that goes. seems to be the easier step. I have a soldering iron Ill try, though in the past, I used one to fix some plastics, and I just made a mess, lol.
Hi Widget the plug should be BSP most likely 1/2 inch , measure across the hole and go to Bunnings plumbing section and get one that is that size. As for the split tank repair, it was discussed here at length recently and the nail polish was claimed to be the best fix. I have not tried it myself
The Briggs normally uses NPT and BSPT will not seal properly. Now of course they might be using BSPT since the engine may have been made in the China and the BSPT is popular China which would explain the thread sealant I see on the plugs.
BSPT (British Standard Pipe Thread) is similar to NPT except for one important difference. The angle across the flanks of threads (if you sliced the fitting in half long-ways and measured the angle from root to crest to root) is 55 degrees instead of 60 degrees as it is for NPT. Thus an NPT male will fit into a BSPT fitting or vice versa but they will not seal. This is a popular fitting in China and Japan but is very rarely used in North America unless the equipment to which it is attached was imported. Thread sealant is needed to seal the male and female fitting together.
For the purpose of the exercise here AVB BSP will do the job because it is readily available here and remember we are talking about a motor that is probably toast anyway
For the purpose of the exercise here AVB BSP will do the job because it is readily available here and remember we are talking about a motor that is probably toast anyway
Understood but it was worth noting all you need was a thread sealant.
But as OP said it run without oil so I agree it is probably already too far gone.
Last edited by AVB; 11/06/1809:24 AM. Reason: spelling correction.
BSPT (British Standard Pipe Thread) is similar to NPT except for one important difference. The angle across the flanks of threads (if you sliced the fitting in half long-ways and measured the angle from root to crest to root) is 55 degrees instead of 60 degrees as it is for NPT. Thus an NPT male will fit into a BSPT fitting or vice versa but they will not seal.
There is another difference, with most of the pipe thread sizes - except for 1/2" and 3/4" sizes [both 14tpi], BSPT and NPT have different thread pitches! So except for those two sizes, the fittings won't engage for more than a couple of turns.
NPT plugs and fittings are available in Australia, from industrial suppliers of hydraulic/pneumatic equipment.
Cheers, Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
It's amazing how bolts will just drop off at times, even though this is usually rare. Vibration will do it over time, usually a very long time, although I have seen exhausts un-wind before my eyes due to vibration, even though they were put on very tight.
I also had all four bolts come off on a Rover mower disc one time, which has me baffled to this day. I had only just put them back on and had tightened each bolt fully. I had a mulcher plug fitted in the rear and was mowing some very heavy, soft clover, which contained a lot of moisture. I went three rounds of the lawn and next thing the entire blade disc dropped off and almost burrowed itself into the dirt underneath. I could not believe it. Every bolt had unwound until they had fallen off. I've never had that happen before and it has never happened since. I put it down to Gremlins.
I am way off topic here, but just thought I'd throw in a couple of similar "dropping off" moments, if for no other reason than sympathy. :-)
Went outside with my metal detector to have a look for it, but before I started swinging, I saw the plug in the grass :p. Still looks intact, screwed it back it. Just gotta buy some blue threadlock, and see how that goes.
I might have to check the bore too, though the mower still spins over, hopefully the damage (if any) isn't bad enough, and I can still use it.
I also had all four bolts come off on a Rover mower disc one time, which has me baffled to this day. I had only just put them back on and had tightened each bolt fully. I had a mulcher plug fitted in the rear and was mowing some very heavy, soft clover, which contained a lot of moisture. I went three rounds of the lawn and next thing the entire blade disc dropped off and almost burrowed itself into the dirt underneath. I could not believe it. Every bolt had unwound until they had fallen off. I've never had that happen before and it has never happened since. I put it down to Gremlins.
They should have just done it the Victa way with one large nylock nut with locator tabs built in, but no, they are too proud and have to do it their own more complicated way for the sake of it. Any wonder Victa were so popular. Simple and proven.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
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