VIDEO: K301 12HP running bad after rebuild.....HELP!!!!!!!!!!!

[Fordiesel69 271]

http://youtu.be/4E8keiQUg_o

 

Engine is spitting fuel exhaust out the intake, and will not rev up.  It gets worse as it warms up as if the timing is getting too far advanced. 

 

It ran like this prior to the rebuild, but I assumed it was becuase if the rod having 1/4" of play making the engine out of time.  I get a 0.20 over pistion and a new crank + full rebuild.  It runs quiet now excpet for the valve clatter.  I have adjusted them to the lower spec of kohler and the higher spec, and tried improvising.  Nothing helps.

 

I installed newer valves and lapped them in, and it did not help.

 

Is this a cam problem?????  My friend and I triple checked the timing marks on the cam & crank gear and they are fine.

 

I need some help on this one.

[squonk 44,923]

After working on cars for 20 yrs. prior to this, I went by this rule of thumb: If it does the exact same thing as before, what you repaired wasn't the problem. Has the carb been looked at? I've seen seats instantly disintegrate because of the ethanol. It looks like by the paint on the carb it hasn't been overhauled. The fuel level will get high enough to just pour in the throat. I just had this happen on a 14 HP K engine. Running good one min the BOOM.Fuel running out of the carb. I think you need a "Charlie Carb" Also if the exhaust valve gap is too wide it won't open enough and some remaining exhaust gas will still be in the Cyl. when the intake opens causing it to blow out the carb. A worn lobe will do the same The valve train sounds noisy but it could be the video

[JackC 617]

Now that we have ethanol in our fuels one of the first things to do when a carburetor engine runs poorly is to clean the carburetor.

Fuel injected engines to not suffer the same problems because they do not have carburetors and carburetor bowls where the ethanol sits and absorbs moisture and separates from the fuel.  

 

Some do the carburetor cleaning annually and much of the business for the small engine shops these days is cleaning or replacing carburetors.  The ethanol can also cause other problems in other fuel delivery components.

 

Based on the experience I have had with it, Ethanol fuel is like poison to older carburetor engine equipment.  I cleaned two carburetors last year and I still have three garden tractors out of service waiting for carburetor cleanings.

 

I will only use pure gas in them from now on which fortunately I can still buy in NY State but not in MA.  

[Fordiesel69 271]

Its not the carb, I went thru it completely as it leaked bad.  I adjusted it every which way.

 

The valve clatter is noisy, so do you think the cam could be shot?  If it were cracked, how would you tell?

[Anglo Traction 761]

If you are getting Exhaust gasses and fuel coming out of the Carb   , then there is a Valve problem, either timing or seating.

Also check your ignition timing to see if it is too far retarded if you haven't already done so. 

 

What was the condition of your Valve Guides? ...and is the Crankcase Breather Valve working correctly?. I could not quite see if the Dipstick had lifted out of the tube when you started it up,  which indicates excess Crankcase pressure.

[wheeledhorseman 579]

Re the valve clatter, if you haven't done so already, go back and check the valve clearances.

 

I say this because a year or so back I partly rebuilt a K301 to make one good one from two. As part of the reassembly I adjusted the clearances then double even triple checked them having turned the crank over a couple of times between each check. They were perfect but on running the engine there was a dreadfully loud clatter from the cover plate area.

 

I opened up and checked them again. OMG, can't remember which it was now but one had a clearence that was way too large.

 

As I said, I had previously triple checked them and can only assume it had something to do with the valve lifter thingies when I'd set them. It ran fine after readjustment and has been no problem since. 

 

Andy

[smoreau 658]

Replace the condenser and check the point gap timing. Most likely a bad condenser. had one k301 act the same way, changed carbs, coil and finaly the condenser and thats what fixed it.

Edited May 11, 2013 by smoreau

[WH nut 553]

Pull the muffler. We seem to be getting alot of plugged mullers lately

[Fordiesel69 271]

I changed the coil, condensor when I got it.  Thinking that could be the problem.

 

I also replaced the points and gapped them several times trying .015 thru .020 with no improvment. 

 

The breather is all cleaned out and works nice, there is no excess crankcase pressure.

 

Please check out this video of before I rebuilt it.  Pay close attention to the throttle I give it, and the gasses shooting out the carb.  Its this same now that it is rebuilt:

 

http://www.youtube.com/watch?v=aqUJ4h0ogZE

[smoreau 658]

do you have the condenser on the positive side of the coil? It looks that way in the video. it needs to be on the points side or negative side.

[Fordiesel69 271]

On the rebuild, I have the points and condenser on the negative side. And the key switch feed on the positive side.

In the knocking video I believe it was wrong.

Lets just say worst case basis, and the coil and condenser could be bad, would it still spit out the carb like that? I mean sound like exhaust out the carb?

[smoreau 658]

You have a b-100 you could barrow the coil and condenser to eliminate that as a issue. Your problem is strange and resembles a valve problem, but I had a k301 that ran just like that. spit gas out the carb and the condenser was the problem. if the carb was delivering too much fuel, it should have black smoke coming from the exhaust. Just saying if you have a good running engine you could swap parts from will help eliminate possibility a part in question. 

[MalMac 1,333]

Just a guess here but I have seen engines do something similar when the crankcase vent was in backwards. Vent not Letting pressure escape through the vent.

[WH nut 553]

Pull the muffler before you start throwing parts at it

[Trouty56 567]

Pull the muffler before you start throwing parts at it

This is worth a try. Simple to check out. At least see if there is good pressure exiting.

[Fordiesel69 271]

I opened the dipstick to let pressure out = no improvement.

 

I have left the muffler off the whole time, also with no improvement.  I put it on for the video so you could hear the gasses out the carb.

[WH nut 553]

Wild ass guess here now, you do have battery cables on corretly and you arent spinning it backwards?.

 

Aslo can run a compression test

[Fordiesel69 271]

Wild ass guess here now, you do have battery cables on corretly and you arent spinning it backwards?.

 

Aslo can run a compression test

 

4 cycle engines CANNOT start backwards.  Some 2 cycle engines, and some diesels can.   

 

This engine has an ACR, and I did end up getting a spring for it, so I will not be able to run a compression test.  Its freshly rebuilt so new 20 over piston + rings + new fresh lapped valves.  No improvement.

[WH nut 553]

 

Wild ass guess here now, you do have battery cables on corretly and you arent spinning it backwards?.

 

Aslo can run a compression test

 

4 cycle engines CANNOT start backwards.  Some 2 cycle engines, and some diesels can.   

 

This engine has an ACR, and I did end up getting a spring for it, so I will not be able to run a compression test.  Its freshly rebuilt so new 20 over piston + rings + new fresh lapped valves.  No improvement.

 

I have seen then run backwards, not for **** but they ran. Even with the ACR you can run a compression test, should be about min 60 when spinning at starter speed

[smoreau 658]

ACR? Please enlighten me on this.

[Fordiesel69 271]

ACR= automatic compression release.  There are flyweights on the cam that need a little spring pressure to arm themselves.  This spring was broken, so I was able to get one in a timely manner.  They work perfect.  With the ACRm you cannot get an accurate compression reading while cranking.

[WH nut 553]

ACR? Please enlighten me on this.

 

 

 

 

Automatic compression release

[Martin 2,133]

is the acr working as it should? it only should be bumping the exhaust valve while at cranking speeds. do you know that its working as it should once the engine starts?

[Martin 2,133]

just went and googled a bit on kohler acr and valve timing seems to keep coming up.......if acr is working ok, look at valve timing again......

most examples were with keyways sheared on removable gears, either on crank or camshaft. since your engine has fixed gears, i would be going back and scrutinizing the valve timing. at least run it through a few cycles with the head off so you can see if you have complete valve sealing at tdc on the comp stroke. you could also check sealing of the valves by pouring some carb cleaner, thinner, in the depression around the valves to see if you have leakage or a valve is slightly open. at tdc those valves should be tight. if the breather cover is off you could also make sure the cam followers are able to turn with no pressure holding them. you should have the valves tight against the seats for at least the dwell time the piston is at tdc i would think. were the valves lapped to their seats properly?

 

i know youve said you checked it several times, but you wouldnt be the first to double and triple check and it still be wrong. i always mark them with a permanent marker to make it easier to see. some of the kohler singles its difficult to see properly. after i mesh them i always rotate the crank back and forth to make sure as they come together that the position is correct. 

 

if you take a step back and take the symptoms the engine is displaying in simple terms, something is allowing the combustion gasses to escape the chamber when they should be held tight in there to force that piston back down the cylinder. some of them are coming out the intake. so either valve seats are leaking or you have a problem between the intake and exhaust ports. but you still have nowhere near any power from that engine, so im leaning towards compression escaping through valve seats in someway or another. either by leaking or incorrect timing, there is a sealing problem or with valve timing the cam could be off in some way or another .......happy investigating.....

Edited May 12, 2013 by Martin

[MarkPalmer 81]

Just got back home and had a chance to look through this thread.  How was/is the condition of the valve guides? These is a lot of valvetrain noise that new valves and tappet adjustments didn't correct, plus the positive pressure and exhaust gasses coming out the intake, both conditions indicate badly worn guides.   

 

Are you absolutely sure the breather is on the right way, with the reed valve facing the outside of engine, small hole on plate down? 

 

-Mark-