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I did a complete rebuild on a 6 hp Tecumseh OHH60 horizontal. Drained the oil and noticed some plastic pieces so I opened the crankcase and the governer gear was busted. I replaced that and dropped the valve lifters while I had it opened up and cleaned them. I put a new crankcase gasket on and closed it up. I removed the valve cover to take the head off. I cleaned up the piston head and valves, put a new head gasket on and closed it up. I never removed the piston. Cleaned the carb up, twice over. Tried to start it, it seemed to have very weak compression and would not turn over. I checked the plug, good spark but couldn't smell any gas on the plug or in the cylinder. To rule out some simple timing issues I removed the flywheel and replaced the flywheel key. I removed the valve cover and realized the valves didn't have any clearance, way too tight, so I loosened them up and set the proper clearance. I closed it up and tried and the compression was very strong. This is where I ran into an issue that I haven't encountered before. When I pulled the cord I could barely pull it through the compression stroke. I sprayed a bit of starter fluid in the carb and when the fluid got into the cylinder and I pulled through the compression stroke it and got an ugly surprise. It fired and yanked the cord back into recoiler but did not start. The spark definitely lit the starter fluid but I'm guessing something is messed up with the valves and the exhaust had nowhere to go. I'm sure I made a rookie mistake and I'm probably overlooking the obvious. I may still have a fuel deliver problem but I can't worry about that until I can get it to turn over correctly. Some help here would be greatly appreciated.

You said that you dropped the valve lifters, which makes it sound like you removed the camshaft. Did you get the timing marks lined up correctly.

Sorry, I meant to address that, yes, I lined up the dots. That certainly sounds like the problem though. If I don't get any other suggestions I'll open the crankcase again and double check everything. I just wanted to avoid that if I could

Did you check the valve clearance after you reassemble the engine? If you interchanged the lifters, you changed the lifter-valve stem clearance. I would start there.

I had checked the clearance only after I had reassembled it.

I opened it up again, the marks were lined up on the camshaft. I dropped the lifters again. The lifters were identical. Same height, same diameter, identical. The valves of course are different sizes and cannot be interchanged. Anyway, just in case I had swapped the lifters before and it did matter I switched them. I removed the head and checked the valves, they were nice and clean and tight. They were not sticking or turning under my thumb. I put it back together and set the proper valve clearance. It appeared to have very good compression. I could not get it to turn over. Getting good spark, just wouldn't turn over. Fuel flowing good through the carb when I hit the primer bulb. I sprayed a little starter fluid in the carb and pulled the starter cord. It fired up the starter fluid and turned one stroke, again it jerked the starter cord from my hand and it seemed like the engine turned backward that one stroke like it was trying to find a way for the exhaust gas to escape. I'm pretty sure some exhuast gas blew back out of the carb. I could be wrong but it seemed as though it did. The engine would only fire that one stroke, once it lit the starter fluid and burned it out it would not turn over again. When I had it apart the piston stroked through the cylinder smoothly, no problems. I have not removed the piston or checked the rings. The cylinder is nice and smooth, no scratches or grooves. The only thing I have done in the crankcase was to replace the governor gear, but I can't see where that would cause any of these problems.

I should add that this was not a running engine when I got it, it was a "parts engine" but all it needed was the recoiler and housing cover. Having taken it apart I figure they scrapped it when the governor gear busted up, but apart from that I can't see any problems with or any obvious reason why it isn't acting right.

Alright pros, I need some help. So I completely broke it all down again and just started from the ground up. Very long story short, I got it running but still have a couple of issues. The first is a fuel delivery issue. I've had a few of these Tecumseh OHV horizontals and I know that on a cold start you have to stay on that primer bulb. I did a complete carb overhaul, both welch plugs, everything, new float, etc. As long as I stay on the primer bulb I can keep it running for a while but even then it will die after about a half minute or so. Can't get it to start without starter fluid and can't keep it running without staying on the primer bulb or throttling it.

The more concerning issue. It is still having a problem when I pull the starter cord. Now it will either fire up and run or it will hit one very powerful lick, again jerking the cord out of my hand and it will not fire a second stroke. I have to give it a bump of starter fluid again.

I'm an amateur and I'm sure this is just stupid rookie mistake. I hope someone can help. I've never felt and engine hit that first stroke so hard without starting.

If the starter rope is being jerked out of your hand, it is a prime indication the the flywheel key is sheared or partially sheared. If you must keep priming, this is normally caused by a lean mixture. Did you check the float level when you rebuilt the carb. If you did not push the new seat in far enough, that could be the cause of the lean condition.

Thanks Rivet, I thought of the flywheel key and I had already replaced it with a new one. The old one looked good but it was still doing the same thing with the new flywheel key. I have it running now and it will struggle to stay running, it does sound like it is running lean. I know that I definitely pushed the seat in all the way, I was worried that I had pushed too hard. The float sat level when I put it back together. It will still occasionally jerk the cord back when I start it but not every time. It is starting now without starter fluid and I don't have to stay on the primer bulb once it warms up. It is just running so lean, struggling to idle and eventually it will shut down on its own.

Many of the problems seemed to have self corrected. Don't ask me how. It is not responding well to the throttle, again I think it's a problem of running lean. Aside from the float what else would cause it to run lean?

That's what I love about this forum, it makes me think about my own problems. Sometimes just sitting down and describing your problem gives you some clues. Anyway, I went out and pulled out the idle jet on the side of the carb. Sure enough, the port on the tip of the jet was completely clogged. I'm hoping this is what was causing the low idle trouble and lack of response to high throttle. Too late to test it tonight, I won't be able to rest until I can test it tomorrow. I'm hoping this solves the majority of the problems with this engine.

This is what happens when you try to salvage a "parts engine" but I love the challenge of making it work when others couldn't.

Engine bogs down when I give it gas. Now this engine is starting okay, still a little hard to start when it's cold, but it is idling good. When I give it a little throttle it bogs down. I've seen people give a number of possible solutions but I'm hoping someone can tell me what is most likely in this case based on this info:

I have added a fuel cutoff switch in the fuel line, I wouldn't think this would affect it but since it is different and a part of the fuel system I mention it. As I mentioned earlier, I've cleaned this carb at least three times over and put a complete rebuild kit in it, new float, welch plugs and all. I found out the idle jet was clogged causing me to have to stay on the primer bulb to keep it running, cleaned it out and not an issue now. I'm positive that i installed the needle valve seat as far as it would go, the float sits level but I did have to bend the needle spring clip just slightly to get it to sit level, the float was a tad too high, so I guess that would make it posssible it was not seated all the way, but I'm telling you, I laid into that thing, I was sure it was in good. I've done a few of those so I know what it takes. The main port in this carb is removeable and I pulled it out and replaced both O rings on the plastic stem. There is no small hole on the side of the main port on this carb. I cleaned the bowl nut throughly. It has the simple flat bowl nut with the opening in the center of the threaded end and the two small holes passing through it. I have a bowl nut with the adjustable needle, it came with a rebuild kit I got somewhere down the road, I don't think it's meant for this engine and I don't know that it would help with this problem but I have it and can try it if there is a reason to.

There are only two welch plugs on this carb, one on the outside with four or five small holes underneath and one welch plug inside the bowl. The carb is on tight and new gaskets were used so I wouldn't think it was drawing in any excess air. I checked the spark plug gap and it is correct. THe valves are both in good shape and seated properly with the correct clearance. The governor gear inside the crankcase was busted and I replaced it with a new one, it spins smoothly.

So does anyone have any thoughts about this? I'm sure you all are tired of hearing about this engine! As soon as someone gives me the magic advice I promise to quit posting about it!

Alright, I guess that means you are definitely tired of hearing about this engine. Thanks Engine Man, great advice. I guess that's how you get 1,000 posts under your belt.

Yeah, we all keep posting, hopefully we get something right now and again!!!!!

The float on Tecumseh doesn't sit level. It actually leans down on the side opposite the pivot pin. Should be able to insert a 11/64 drill bit between float and body of carb, without the gasket.

Thanks Engine, that the kind of experienced advice I was hoping for. I'll see if that helps.

arch252 said:

Alright, I guess that means you are definitely tired of hearing about this engine. Thanks Engine Man, great advice. I guess that's how you get 1,000 posts under your belt.

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Its got nothing to do with getting more post, you are having a problem with the carb and you ask for advice, after all you have done you still having the problem, so I told you to replace it that way it would show you that it is the carb, you don't have to take my advice do you.

Fish said:

Yeah, we all keep posting, hopefully we get something right now and again!!!!!

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So that's what you are up to...!

I understand, I guess I was being overly sensitive. I thought you were just being a smart a@%. I'll take my skirt off and put on my big boy pants.

I don't have an extra carb for this engine or I would try that, thanks though.

Have you thought about using one of them ultrasonic cleaner, I don't use them but there are members on here that do and are not disappointed in the out come. may well be worth looking into.