DavidB 2 #1 Posted May 6, 2021 No start seems to be a pretty common thread here; please bear with me. I acquired this Wheelhorse 244-H in a non-running state. Unfortunately it's still in that state. Compression tests at 95 psi which seems low to me but the manual calls for 70+. I've had the head off and the piston and cylinder look to be in excellent shape with no scoring or other visible damage. The valves look good and are tight in the guides, but since I had the head off I lapped them in anyway. The flywheel is correctly mounted and the key is not sheared. Valves are gapped at 6 thou on the compression stoke at TDC. Brand new plug, gapped at 35 thou. The coil seems to be in good condition as it is creating a spark at the plug. Carb has been removed and cleaned. Float height adjusted. Fresh gas. When cranking I get a periodic backfire through the inlet, and that's all. There doesn't seem to be any combustion taking place in the cylinder itself. This leads me to think that either the timing is off (although I don't see how it can be as there's no adjustment possible other than the .020 gap between the coil and flywheel), or that the valve timing is off somehow. I've been fighting with this for a week now, so any help or suggestions would be most welcome. Thanks. Share this post Link to post Share on other sites
DavidB 2 #2 Posted May 7, 2021 Further to this thread, this is the idle mixture screw from that carb. Note the step in the needle profile. I haven't been able to find a good image in either the user's manual or the parts book, but it looks to me like the needle has been damaged at one time. Can anyone confirm whether that step is normal or not? I've also been unable to find this part as a separate item anywhere - it seems that I'd have to buy a complete carb kit ($200) to replace it, so any other ideas would be most welcome. Thanks. Share this post Link to post Share on other sites
8ntruck 7,833 #3 Posted May 7, 2021 Does it fire if you put a bit of gas directly into the carb? Is there gas on the plug after cranking? Do you know anything about the history of the engine? It is possible somebody was in it and got the cam out of time on reassembly. to the forum. I'm sure others will be along in the near future with other suggestions. Good luck. Share this post Link to post Share on other sites
oliver2-44 10,711 #4 Posted May 7, 2021 While I’m not familiar with that model, here’s a basic approach. 1 you said it has spark 2 it has enough compression to run 3 so to prove timing and the above items, do As others have suggested and put a squirt of gas in the cylinder and have some gas in a squirt can. Prove that it will at least go barroom, or run for a few seconds If it does look at the fuel system 1 You said carb has been cleaned 2 Verify your getting fuel to the carb. (I’m guessing this has some sort of fuel pump) Disconnect the fuel line at the carb, does fuel come out with good strong spurts when you crank it? 3 if gas flow is poor disconnect fuel line to fuel pump and see if it has gravity flow. If it flows fuel pump may need cleaning or replacement. 4 Many tank shutoff valves have a screen on them that fits inside the tank. This screen and the valve itself can plug up Since you prove it will go carom, Now would be a good time to put new ethanol resistant fuel hose on it, and maybe a new tank fuel valve Good Luck, keep us informed PS make sure your muffler isn’t plugged up. When you crank it you should be able to feel some air coming out. Share this post Link to post Share on other sites
DavidB 2 #5 Posted May 8, 2021 Thanks for the suggestions. There is gas on the plug after cranking. I don't know for certain that the engine hadn't been previously torn down, but there's no obvious evidence that it has. As for the cam being out of time, valve timing seems to be reasonable at least. I don't have the tools to measure precisely, but EVO (exhaust valve opens) at about 120 degrees, IVO about 340, EVC at 360, and IVC around 240 degrees on compression stroke (120 BTDC). Ignition starts around 20 degrees BTDC. When I flood the carb with gas (or use quick start) I do get a popping sound as if there's some ignition happening, but it's not enough to start the engine. Might just be the fumes in the intake manifold - don't know. As for fuel management, there is no pump - just gravity feed - and the flow is good. So, still stumped. Share this post Link to post Share on other sites
DavidB 2 #6 Posted June 3, 2021 Just to close off this thread. I was getting spark, but it turns out the coil was damaged, so the spark was intermittent and weak. Swapped in a used Briggs coil (had to ream out the mounting holes, but better that than paying $200+ for a new replacement) and she's running! Now to get the carb sorted out. Thanksa everyone for your ideas and suggestions. Share this post Link to post Share on other sites