Missing: combustion for engine, clue for owner

[Tom Deutsch 0]

Still can't get the beast started.:( What's the easiest/safest way for me to test for spark on my 917 (KT series II)? If I remove the plug, attach the lead, hold the plug near the chassis and crank the engine should I be able to see a spark? Or can I just pull the wire and hold it near the top of the spark plug electrode (will a spark shoot out that far?) I appreciate the comments I got on my last post about this same problem. I have tried replacing the spark plugs (the ones the dealer sold me look different size-wise than the ones that were in there!). Old plugs looked fine. New plugs didn't start it, except I did get a "backfire" after the first crank with the new plugs. Is that a clue? Also, as was suggested, I did notice I'm getting gas leakdown into the oil (can smell it in there). I'm going to change the oil and install a fuel shutoff, but that won't start the engine! I've been cranking with the charger on the battery so I'm sure I'm getting plenty of cranking power (just no combustion in the chamber!) This machine was running just a few days before it refused to start last week. What's next, anyone? Clean the points? Replace the condenser? Test something with my multimeter? (I know how to turn it on and how to identify a red and black wire -- that's a start, right?)[:0]B):I

[MPH 12]

Either way you mentioned checking for spark should work. Bye ground the plug to the engine you also check the plug. IF you don't have spark, then check out the points and such. IF you have spark, check for fuel and compresson. If you run it much with gas in the oil you may be lacking enough compression to start.

[UCD 14]

Gas in oil sounds like you might be flooding the engine and fouling the plugs. To check for gas in oil, if it has a dip stick pull the stick and take a lighter to the end of it, if it flares and burns there is gas in oil. If no dip stick use a screw driver insert it into the oil remove it and test with lighter. When you pull the plugs are they wet? If they are dry them with a propane torch. With the plugs out open the throttle wide open and crank engine over to dry cylinders out. Reinstall plugs and with throttle closed and no choke try again. If the plugs are dry when you remove them try squirting some gas into each cylinder and reinstall the plugs and then try starting, if it fires you have a fuel problem.

[HTews 0]

I have seen on high milage cars, if you flood the engine it washes the oil off of the cylinder walls and you loose compresssion and the engine won't fire. I have see this happen on a briggs and Kohler also. My fix was to squirt some oil into the cylinders and turn the engine over to distribute the oil on to the cylinbder walls and then reinstall the plugs and see if it will start. Sometimes you will fouls the plug with oil but you can just spray the plug off with carb cleaner and re-install and try starting it again. Hope this helps.

[Tom Deutsch 0]

I love this place! I think you guys may be on to something with the loss of compression. That makes sense. I'll install the fuel shutoff, change the oil and dry the chamber before I trying starting again. Hopefully I haven't damaged anything with my gassy oil!

[Guest]

If it been siting for a wile i would change the oil,clean gas tank,new plugs,fuel filter now i lik the see through to tell if the motor is geting gas ,little more costly but it worth it when your stalled out in the driveway and won't start.Anyway i take and clean out the carb dont wan't bad gas in the motor,then look at electrical point ,fuses and butched and hackered up wireing, if you don't youll put a whole new term to fire it up!!!!!!!!!!If it still wont start then you should pull the motor off and rebuild it.It's very important not to rush.I my self had messed up the whole motor when i got into a rush to start it.have fun don't go cheap.

[Guest]

That apply even if it hasn't been siting i read through it too fast the first time than reread it.if it still not any older than 1970 just put new points in and.if that don't run ceck for new piston rings.Once i had my ford tractor ran it for 1 hr mowing.A few days later i had to trim up wouldn't start much like yours i tried every thang took off the valve cover and they shoot out and was melted but it was alunminum with no sign of over heating or anything.try that

[biggie_rat 0]

Tom's post reminded me of when I was teaching Health and Safety classes for new employes at the GM plant in Muncie (musclecar Muncie Rock crusher 4 Speeds, amoung others). I'm not sure now how I would fit this in to what I was teaching, maybe an ice breaker, but I would say - I have worked on small engines for XX years on the side and when someone would bring me a mower all they would tell me was, it just wouldn't start. So the first thing I would do to try find out what the problem was to take the spark plug out, squirt some lighter fluid in the spark plug hole, put the plug back in and if it started and ran for 2-3 seconds, the carb is probably the problem. If that didn't do it, do a thumb style compression check with the plug out, then crank it over. If it sucks and blows your thumb in or out, that area is possibly okay. The last check would be for spark. I told them this would require a little help, maybe from your wife. Get her to hold onto the spark plug wire while you crank it over (by then I was getting plenty of chuckles from most of the guys, none from the young ladies), then ............ if she screams and tries to hit you with something ......... then you know you have spark. After the laughter died down, I would say, BUT, that only works once.

[JimS 1]

Spraying some starting fluid into the carb will usually get it running if the spark is OK. BTW did you check the plug gap? usually 0.020 inches.

[HubbardRA 19]

If you have gasoline in the oil, it probably won't start because you are directly sucking gasoline vapors into the cylinder from the crankcase breather. I had a carb that would leak and fill up the crankcase with gasoline. It would not start till I changed the oil. That was a vertical shaft engine with a horizontal flow carb. On that one the gas could leak thru the vent tube and not thru the cylinder and past the rings. This actually happened once while I was mowing the lawn. Replaced the carb and fixed the problem.

[lboy1971 0]

for checking spark I've had one of my nieces hold the plug while I pulled the starter rope. This method works very good, although if the plug does fire you can't get them to hold another one for ya, or come anywhere near you if you are working on an engine, lol.

[dhardin 0]

Spent a lot of my time as a kid watching and helping out some oldtimers around the repair shops, I'v seen many amazing shop tricks. A guy brought in a old L head to see if the guy could get it running for him. He said it had been seting out side for years and he wanted to know if it was worth fixing. This oldtimer said he was busy but he would do a quick check, He pulled the plug wire off and held it in his hand and gave the pull rope a quick pull, and smiled. Changed the spark plug. Checked the oil, added some. Then he went under the bench and got a small propain tank (one like you use to sweet copper pipe together) it had a small plastic tube attached to the tip and he ran it into the carberater and seamed to place it in the open butterfly. Put the plug wire on and gave it a pull and it started. With a little adjusting of the propain gas valve it ran better. He charger the guy $5.00 for his two min test.

[maxtorman1234 0]

One time we were using our 917 with the kt19 series II , and it worked like normal, next day it wouldnt fire. I replaced the points,and it went like usual.