416h Onan p216 lost spark

[Handy Don 13,586]

@lynnmor would counsel going a bit further, especially if the engine is off the tractor or has upwards of 800 hours SLMO (since last major overhaul) or has performance issues. 

He'd have you adjust the valves and pull the heads to look for carbon and valve condition and verify that the intake manifold isn't leaking air or being eroded by contact with the manifold shrouds. Next would be a thorough carb clean.

However, unless you have suspect performance, these may be readily postponed for now.  (You would need gaskets for the heads, manifolds, valve covers, and the carb, too!) 

[Handy Don 13,586]

11 minutes ago, Jhook said:

dropped one of the three 5/16 screws that hold the air box on down the throat of the carb

My then 10-year-old brother was trying to help and dropped an aluminum nut into a VW engine I'd rebuilt and was installing (the still-to-be-mounted generator's bracket doubled as the oil fill tube so it was open). What can you do? He still tells people that he was surprised I didn't yell at him (or worse). Took a day's work to retrieve it from where it had bounced into the oil pump intake ready to wreak havoc with the pump gears had I started the engine!

 

Sounds like you'll likely have the shrouds and intake manifold off so maybe the rest makes sense, too.

[lynnmor 7,673]

1 hour ago, Handy Don said:

unless you have suspect performance, these may be readily postponed for now.  (You would need gaskets for the heads, manifolds, valve covers, and the carb, too!) 

If a valve is in need of adjustment, it should not be postponed because a leaking valve can lead to more work and expense.  Onan suggests 1000 hours but with the varied usage of a tractor I say 750 hours is plenty.

[Handy Don 13,586]

2 hours ago, Jhook said:

This onan really makes me appreciate the simplicity and reliability of the kohler ch15s command pro thats on my 315. 

There is no doubt that the twins are challenging to work on, compared to singles. Still, if you want the extra four or five ponies, amazing torque, and very little vibration then the twins are a great thing!

[Jhook 849]

6 hours ago, lynnmor said:

If a valve is in need of adjustment, it should not be postponed because a leaking valve can lead to more work and expense.  Onan suggests 1000 hours but with the varied usage of a tractor I say 750 hours is plenty.

Ok i will look into that. No performance issues at all. Ran great. The only hiccup was if you throttle up too quickly from idle it would sputter and die. Throttle up slowly and itll go nice and smooth to full throttle. Now the question is can the heads be removed and valves adjusted without pulling the engine? Im not against pulling it, but i work on everything outdoors under my deck, unfortunately i dont have a shed or garage right now. Just this small workplace with no protection from the elements other than the sun. 

[lynnmor 7,673]

There is no need to pull the heads to adjust the valves although it might be a good idea to de-carbon them at this point.  It sounds like you are going to pull the carburetor to remove that screw and that usually involves removing the intake manifold.  The valve covers are just under the intake and are removed with just one screw each, the adjustment takes place in there.  Since you have performance issues when quickly opening the throttle, that indicates a dirty carburetor or a bad accelerator pump if it is a later model that has one.  You don't have performance issues caused by valves that need adjustment until it is too late. You will need new exhaust, intake, carburetor and valve cover gaskets to do this job.  Also, a small torque wrench that reads well at very low settings is needed.  See the manual for torque specifications and don't guess.  Always keep the choke closed when the air filter cover is off to keep things out of the engine, and use blue thread locker on the screws that hold the air filter to the carburetor when assembling.

 

Whatever you do, clean up that mess before proceeding with more disassembly.  I don't use a pressure washer, that is asking for trouble.  Gunk Original engine cleaner, a paint brush and a garden hose works just fine.  Purple Power cleaner is another powerful cleaner that works very well but it can damage paint and aluminum if left on for more than a few minutes.  Be sure to clean under the engine, there are fins on the oil pan to cool the oil.  At the top of the timing cover where the governor shaft sticks up is a small seal, be especially careful there so as to not force dirt, water or anything in it, but do place a few drops of oil on it regularly.

[Jhook 849]

Been busy lately but at least got parts ordered finally. I ordered the following thru onanparts. 

Ignition module

Rotor

Condenser

Ignition module insulator

Flywheel key 

They came all together in a kit for like 245 bucks which wasnt terrible. If this doesn't fix it i will just swap the engine or park it for a while til time frees up.  Work is too busy to be messing around with it too much, especially with a brand new subcompact TLB on the way.