G-man 0 #1 Posted April 24, 2011 I have an interesting problem with my D-200, 20 HP twin cylinder Kohler engine with Ark front loader. This tractor had been converted to twin exhaust stacks before I purchased it. Upon starting the tractor I see a small puff of white smoke coming out of the left exhaust stack only. Then usually what happens is over time it seems like the left stack will build up pressure and make a single "pop" noise accompanied again by the white smoke. It is a pretty loud pop but not back-fire loud. It will do this every couple of minutes. The problem seems to subside a bit the longer I let it run. I thought it might have been a stuck valve, so I removed both valve covers to compare them. They appeared to be moving ok but the exhaust valve guide on the bad side seemed to be "spinning" more than the other cylinder. Some things I have done. 1)I wiggled the "spinning" valve guide a little to see if it had any effect. 2)I pulled the spark plug on the bad side. It was l little dirty but not bad. I cleaned it up and the popping is still happening. 3)I noticed that the crankcase breather tube was shortened and had a bolt screwed into it so I removed the bolt. I am looking for suggestions on this. I did have a suggestion that it could be the breather valve? One more thing... I noticed the "bad" side's exhaust is running much cooler than the other, at least at first. The right stack after 5 minutes was hot, the left stack was cool enough to touch. Perhaps this indicates an ignition problem on that side? Thanks! Chris Boston MA Share this post Link to post Share on other sites
VinsRJ 721 #2 Posted April 25, 2011 :thumbs: I will leave this to the experts..... Share this post Link to post Share on other sites
Kelly 1,028 #3 Posted April 25, 2011 If you think ign. try swapping plugs from side to side, do the same with the plug wires, the coil fires both plugs at the same time, just one cyl. is at on the compression stroke the other is on exh. stroke, so you can switch the wires in the coil also it does not matter where in the coil the plug wires are, puffing white smoke makes me think oil, as you said plugged breather and maybe a loose valve guide on that side sucking a bit more oil, not sure? but try one thing at a time so you know what fixes it, if it fixes it. One more thing try spraying carb cleaner at the base of the intake on that side, see if the engine picks up speed or stumbles it might be a intake leak and that can cause the exh to run at diff. temps, by getting more air, and seals up as the engine gets warm. Share this post Link to post Share on other sites
JC 1965 1,528 #4 Posted April 25, 2011 :wh: Hello and :thumbs: Share this post Link to post Share on other sites
G-man 0 #5 Posted April 26, 2011 Thanks for the welcome and the good ideas! Kelly, I cleaned up and switched both of the ignition wires and no change I also cleaned up all the connections on the coil. I did not switch the plugs yet because I ran out of time last night. I was trying to check the breather valve, my problem is I am having a bit of a problem locating it! I will be removing some covers tonight to try and find it. Shouldn't it be around the valve cover? Share this post Link to post Share on other sites
G-man 0 #6 Posted April 27, 2011 After switching cables from the coil, a little white smoke turned into a lot of white smoke on the bad side . I was thinking piston rings maybe. I actually took the cylinder head off on that side and it didn't look too bad in there. Valves weren't burnt and the valve seats were clean. There was no evidence of any excess oil in the combustion chamber. I will have to do a compression test. The saga continues. Share this post Link to post Share on other sites
corn53 4 #7 Posted April 27, 2011 :thumbs: Good luck with the repair!!! Keep us posted... Share this post Link to post Share on other sites
tunahead72 2,346 #8 Posted May 9, 2011 So...? :hide: Share this post Link to post Share on other sites
puddlejumper 67 #9 Posted May 9, 2011 How long did you let it run after you made the switch? Did it clean up any after running awhile? And did it make any differences cooler exhaust on the good side. Share this post Link to post Share on other sites
G-man 0 #10 Posted May 15, 2011 Sorry for the delay. I have the problem solved! Basically, I removed the other cylinder head on the side that was not popping and there was considerably less carbon buildup there, making me reconsider the problem. I went and bought some Seafoam spray and really gave the combustion chambers and valve seats a good cleaning. I then started thinking about ignition again since the popping side, exhaust stack was colder in temperature. I pulled both plugs and the gaps were off a little. I then cross referenced the NGK part number of the installed plugs and found the previous owner had installed the wrong plugs for the engine anyway. I went to Tractor Supply and got the right ones. After I put everything back together (and retapping an exhaust manifold thread along the way) I started it up. Immediately, the temps were the same on both exhaust stacks. After some white smoke from the rest of the carbon and cleaner burning off, it runs great! No pops, no smoke! I guess the popping was from the carbon buildup that was caused by the low temperature plugs. The carbon then getting heated and causing little backfires? If anyone has a better idea let me know. Thanks for the support! Chris Boston Mass Share this post Link to post Share on other sites
tunahead72 2,346 #11 Posted May 16, 2011 Excellent, I love happy endings! :hide: Share this post Link to post Share on other sites
