Hey guys like to add my 2 cents and maybe get some help. Mine is the 18hp ohc,wont turn thru the comp stroke with a known good battery,starter good and all connections good,set the valves at .004 1/4" past tdc. I understand you should see a slight decompression coming off the cam just b4 tdc. I have no movement in the pushrods whatsoever. Suspecting bad cam. How do I get to that? Anyone know where I can access a disassembly/shop manual? Im kind of over my head here. Doing favor for my neighbor. He says go for it but I would like some kind of instrucions. Thnx

I have a very similar problem with a Briggs & Stratton 17 HP engine. I have put in a new carb overhaul kit. (The float was gunked up pretty bad, but now looks new, checked for leak or holes in it, found no indication that float is damaged.) Put carb back on engine. Engine runs, but poorly. It sounds likes it chugging, noticing black smoke out of exhaust especially at Idle. One thing I didn't notice in all the above posts. Is the adjustment needle on the carb an IDLE adjustment needle or a main needle? What is the initial setting? The engine does have spark. Although one spark plug shows more of an orange spark rather than blue. Both plugs were damp from unburned fuel when I removed them. (They are old plugs.) Engine running: It'll sit and run. I can drive the tractor. However when I slowly engage the mower blades (blades are new, bearings are good, belt is new) the engine dies, unless I quickly disengage the blades and apply full choke. Heading out to store to get new spark plugs this morning. I've already poured quite a bit of money in this beast. I may be the one who has a rolling ball of fire!

Hi, I have a problem with starting my Lawn Tactor, I hope you can help. First some Specs: It is a (heap of junk - ha) B&S 18hp Twin I/C M/No: 422707 Type:1263 01 Code: 9312065A on a Murray Lawn Tractor. It doesn't appear to have any form of fuel pump unless it is part of the carb. (I believe it is gravity fed). A little history: For some time I had been having to leave the choke on just a little to make the thing run smoothly. The last time I used the machine I fiddled a little with the various adjusting screws on the carb. with no improvement, so I set them back to where they were. I figured I could live with the choke being out a little. My problem is that the last time I used the machine it died on me after about 1-2 hours mowing and simply would not start again. I figured it had simply overheated so I pushed it into the garage. Now (a week later) it doesn't want to start, or if it finally does (after lots & lots of starter motor winding), it is only for a brief period and it will run like a pig and backfires and soon dies. It smells strongly of fuel during starter motor winding. When I pull the plugs out after this (and having not started), they are wet with fuel. This makes me think there is a spark problem or a timing problem. I have tried the following: I have replaced the plugs, I know all 3 of the kill switches are working (I checked them with a multi-meter), I made sure the earth wire to the ig. coil wasn't shorting and was working properly with ig. key switch, I pulled the coil off and checked the winding with ohms on multi-meter (this was ok), The coil is approx. one millimeter away from flywheel which I think is fine, I have checked for spark from both leads (with spark test pen) and this seems to be working, I have removed the plugs and grounded them then wound it over and they both have spark (maybe a little weak ?? not sure), I asked a mower shop guy if this thing runs points and as I suspected it is electronic timing (so I don't believe it has anything I can adjust), I even pulled the flywheel off to check there was not a sheared key or something there that may explain the timing being out (key and keyway was fine), I tried starting it without the air filter (just in case some blockage - no help but desperate), I have sprayed some engine start spray directly into each of the cyclinders through spark plug holes and after some winding got it to start and got a "Really Cool" backfire. I am suspecting the coil is "Kangaroo-Edward" ("Roo-Ted" for non Australians) but do not know how else to test it (other than how I have stated above) or whether the spark it is putting out is as strong as it should be. (I thought of letting the wife hold the spark plug lead end and depending on her reaction it might of given me an idea of how strong the spark was - ha ha - but I thought better of it). I didn't want to buy a new coil if it wasn't the problem. I don't believe it is a fuel problem due to the fact the plugs are wet. Am I wrong in my deduction of it being Spark/Timing and what else can I do??? Please help me Fellow Lawn Tractor Guru's, before I just set fire to it and roll it down a hill or beat it with a stick. I know this won't fix it but boy would it make me feel gooooooood!!! (I have read through many of the other peoples problems on your forum and I felt they were all a little different to mine - Please help!) Thanks in advance for any help you can offer. P.S. By the way, I noticed a few people in your forum having a problem with the charging of the battery. I too have suffered this problem in the past. I thought I would mention that when I pulled the flywheel off, that the amount of dirt/dust build up inside of the flywheel and around the stator was amazing. It was packed in solid and coating the magnet faces and stator faces. I hosed all of this away, cleaned the stator faces, blew it all dry and sprayed it all with CRC/RP7 before putting it back together. I wonder if this may be a major part of the problem. I don't know if it has fixed the problem yet because my machine is not running, but I reckon it can only help. I hope this helps.

Yes, 31P777. We now need to consider 2 things that could be affecting this problem. First, when the engine does its "crank a bit" act...........do you mean it acts like it wants to crank but just moves slightly and then stops turning? If you wait a minute it will repeat that? and it might finally catch on and run, sometimes? If that is what it is doing, I suggest that the engine is probably past due for its recommended annual valve adjustment. Have the valves ever been adjusted in the time you have owned the tractor? But, if the action you are seeing/hearing produces a "rapid fire clicking noise" from the starter solenoid for a few tries and then finally does nothing............I suspect that the battery is not being recharged when the tractor is operated. If recharging with a battery charger, or boosting from a good battery produces a dependable cranking, that sort of points toward a problem in the engine charging system. I see that the tractor has a manually engaged PTO system. If there was an electric PTO clutch you would also be complaining that the deck would not stay engaged, and that would be a symptom to weigh in on the non charging scenario. It is real easy to determine whether the charging output is OK. All you need to do is read the battery voltage while the engine IS NOT running and write down the voltage on paper. Battery voltage at this point should read at least 12.3 volts and might even read 13 volts if it has been charged recently. Next, start the engine and run it at full throttle. After running for a minute (and while it's still running at high RPM) check the battery voltage again and write down the voltage on paper. The voltage should read at least 13.7 volts and hopefully as high as 14.3 or so. If you do not observe at higher voltage at max RPM compared to the not running battery voltage, your charging system is defective.