Thread: Lucas woes

these engines are designed to run on unleaded, I'd leave the fuel additives alone. If you are in doubt, you can always drop on to a B&S dearler, recon there would be one close by. The plugs it came with are the ones to keep using.

Just had a phone call from Lucas! So here's the thing they've seen this and had a couple of things to chat to me about.

Warren (the other brother I couldn't remember his name - sorry Warren) was concerned about my heat shield not having any protection for the fuel tank. The way the shield is at the moment, it will more than likely push heat toward the tank by having the opposite side of the muffler shielded and not hte fuel tank side. I'll get neil to add a plate to the fuel tank side.

Reaming the carby - yep Lucas feel this will be an advantage and will help the motor run a bit cooler, So She'll be reamed a bit when the muffler comes back.

Fuel - I'm runing ethanol fuel, when it's available, but will go back to straight unleaded as it burns cooler than ethanol fuel apparently.

The best bit, this is why I love Lucas! Someone from Lucas will pay me a visit in the New Year to have a look over my machine, check things over have a look at her and generally scope things out. Adjust any stuff which needs it, see to any issues. What a good bunch.

Oh and FYI 6" owners the're may be a possibility for a Lucas muffler system different to the B&S one to try and keep the heat away from the water bottle, fuel tank and gas strut

Hi again if you stop using ethanol you shouldnt need to reaming the carby out .
Ethanol will aways make your mill run hot . Will give you a call when we are doing shows up near you so we can have a look over your mill.
cheers Dudley

Running a ethonal fuel will make your engine run 10-15% leaner than on straight petrol , the ethan will burn cooler when mixtures are right BUT you need to richen up quite a bit to take advantage of it.

best to go back to straight petrol and some of your issues will be eleviated

Originally Posted by dudley j

Hi again if you stop using ethanol you shouldnt need to reaming the carby out .
Ethanol will aways make your mill run hot . Will give you a call when we are doing shows up near you so we can have a look over your mill.
cheers Dudley

Thanks Dudley.

This is why I love Lucas! I'm out of warranty, having an issue which isn't really the sawmill's issue, more the engine manufacturer's issue, but the folkes at Lucas will take a look at it to try and sort it out for me.

Bloody Legends

Well, all the above questions can be answered easilly enough with the right test equipment. The fuel mixture can be tested and adjusted with the aid of exhaust gas analysis. Ignition timing is easy enough to check with a timing light (stroboscope). Valve clearances can be checked with a $5.00 set of "feeler gages" from an auto accesory store. My Briggs & Stratton book is about 25 years old and so would be of little use on a modern engine.
If you know someone who is knowledgeable about things electronic you could always build an exhaust gas Oxygen monitor as described in "Silicon Chip" magazine and monitor the fuel mixture whenever the engine is running.
Good luck with the problem,
Dennis.
PS. What do the electrodes on the sparkplugs look like? Grey, cracked, melted can indicate the need for a "cooler" plug and/or a slight enrichening of the fuel mixture. Do you need to use the choke to start the engine, even when it's hot? This can indicate that the mixture is too lean. If the engine can be started without the choke even when cold then the engine could be a bit on the rich side.
Gets worse by the minuite, does it not?

Dennis according to B&S today, there is little to no adjustment for mixture. They did ask about plugs, but I changed out plugs this weekend gone and they seemed like a 'good' used plug from a car (Dad was a mechanic and taught me a few things about 'reading' stuff like plugs) I am equipped to chuck a timing light over it, but don't have a timing mark to check it against - well having said that, I haven't found one??? and don't recall one in the owners booklet I have - I'll go over it and see.

Choke - I only need to use it to start first thing in the day, each other start is fine all day, but I do need it for first start.

Smoke - she doesn't have any smoke at all, cold or hot, on start or not.

Gas analyser - I think the issues with the muffler have been cheap, thin materials. If i had suspicions of other nasties, I'd get it checked, but I don't have indications of other issues - she runs like a dream and cuts like a demon. I dunno???

But thanks for your input

Briggs mufflers, especially on the twin cylinder engines, seem to last ok but my experience is with the vertical shaft motors that you get on ride-on mowers and they are usually a bit further away from the motor (therefore cooler) than the horizontal motors.
If you are happy with the condition of the plugs, and this is a good indication of the goings-on inside the engine, then a better quality muffler might be all you need. Some of the square "jam-tin" mufflers that fit on the 8 to 13HP motors were pathetically thin and didn't last too long at all. Didn't do all that much to quieten the exhaust either.
Can you deflect some of the waste (hot after it has been through the engine) cooling air so that it blows over the muffler, thereby helping to cool it?
Good luck and keep making sawdust,
Dennis.
PS. can you install a bracket on the muffler to hold a billycan of water? That way you can always boil the billy for a cuppa while you work. This will achieve 2 things, you will save time because the billy will boil while you are working and will also save on the fuel needed to boil the water. You will effectivly become more productive and save money. Now, if I can work out a system where you don't have to stop work to drink your tea, think of the increase in production you could achieve!
I think I have done enough stirring, I had better shuddup!

I have a 17 HP B/S vertical shaft motor in a John Deere ride on mower & it backfires on shutdown about 50% of the time & it doesn't seem to matter whether it has been working hard or not to do it, it has done it from new. I think it is because the muffler is so close th the motor & something inside is heated so hot that it ignites the unburnt fuel pumped through the motor after the ignition is turned off
regards inter

Originally Posted by DennisDaMenace

................................
PS. can you install a bracket on the muffler to hold a billycan of water? That way you can always boil the billy for a cuppa while you work. This will achieve 2 things, you will save time because the billy will boil while you are working and will also save on the fuel needed to boil the water. You will effectivly become more productive and save money. Now, if I can work out a system where you don't have to stop work to drink your tea, think of the increase in production you could achieve!
I think I have done enough stirring, I had better shuddup!

I had a boss like that once

eat while you walk

sh?? while you run.

G'day all, had to repair my muffler at around 100 hrs, have running on problem & backfire if I don't run slow prior to shutting down. 18hp b&s.

wayne

How old/hours is your 6-18 now Wayne? has idling down before shut off stopped your backfiring?

Brand new 6-18 had .1 hrs on clock at .5hrs backfire on stopping so I reduced revs slowly and allow to idle before switching off only get a little "Pop" occasionally no more backfire but will monitor shutdown procedure to see what happens.

Shayne

My 27 kohler tends to backfire when idling down, so at Dudley's suggestion, I simply switch off and start on full throttle once warm. No sign of a "pop" if I do that.