KevinO 0 #1 Posted August 28, 2024 I purchased a Briggs flathead 12hp, model 289707 for $100.00 and installed it in place of the too tired 10hp on my 10-32 Wheelhorse. Cleaned the carb, removed emulsifier, replaced what needed replacing. Fresh gas. Engine idled great, but would not run at anything above idle. Backfire thru carb. Put old carb from 10hp on it last night and same. Got even worse, won't run at all now. Will probably have to pull the head? Worn pastic cam shaft maybe even???? Flywheel key tweeked??? Share this post Link to post Share on other sites
Goldnboy 991 #2 Posted August 28, 2024 Possible dirty carb, or governor linkage issues(Briggs are very picky on orientation and alignment of them) ..could possibly be improper coil gap between flywheel. Share this post Link to post Share on other sites
953 nut 57,854 #3 Posted August 28, 2024 If an engine idles well, but runs erratically when revved up, like it hits and misses, pops and backfires, then chances are, it needs a new condenser/capacitor. And always install a condenser/capacitor with the wire facing downward so rain water and/or when washing off engine, water will not enter inside condenser/capacitor, ruining it. With water inside the condenser, this will also allow it to idle well, but cause it to run erratically when revved up. Share this post Link to post Share on other sites
Handy Don 13,340 #4 Posted August 29, 2024 (edited) Points burned or not correctly gapped? Open too far means spark comes too early; open too little means spark comes too late. Edited August 29, 2024 by Handy Don Share this post Link to post Share on other sites
