Kohler sever back firing

[Its Me]

got a Kubota that come in for repairs, the fellow said that it started back firing and died and who not start, removed the plugs, checked for stark, good, checked valve clearance, terribly off, set them, started the engine ran for about 30 seconds, backfire, died, checked the valves again, way off again, removed the heads, thought it might be valve seat pooped out, no, valves not seating good, would it be possible the cam, dont know if it was run low on oil, 500 hours, FX801V-AS13-R

 

[Rivets]

If the valve clearance changes that fast, you may not have tighten the locking nut properly. I would remove and clean all parts, adjusting nut, lock nut and rocker arm, reassemble and torque properly. I prefer dry assembly, no lube or thread lock, which can distort my torquing procedure.

 

[Its Me]

Rivets, I had done that the first time, with the poor results that I spoke of, I removed the heads, and the valves I was shocked at the amount of wear on the valve faces, I have a Sioux valve grinding machine and seat cutters, but if the valves are ground, they will have a very sharp edge, looks like the valves will have to be replaced, looks like Kawasaki has cut quality like the rest of them to increase profit, very disappointed, in several of their machines that come in the shop lately, stopped by the local mower shop which has two excellent, I do mechanic work with them when they start getting to the point where the two-three wait period, he had two tore down, on new had three hours, the oil pump bolts were finger tight, causing no oil pressure, the other like the one I have, with less than 500 hours, same thing with the valves, wore beyond lapping to get a good seat, I am going to give them a lite grind and face the seat good, give it a try, then the customer can decide how much he wants to spend, thanks for your response.​

 

[lugbolt]

they've not cut quality to increase profit, they've cut quality to compete with the other brands.

I've seen the seats get loose in the head, then the seat bounces up and down and wears the head. Then you take the head off, can't see a thing wrong with it other than the valve is sitting deeper into the head than it should be. Seen this twice in 33 or 34 years however long I've been in the business. Both Kawasaki's.

 

[Tiger Small Engine]

they've not cut quality to increase profit, they've cut quality to compete with the other brands.

I've seen the seats get loose in the head, then the seat bounces up and down and wears the head. Then you take the head off, can't see a thing wrong with it other than the valve is sitting deeper into the head than it should be. Seen this twice in 33 or 34 years however long I've been in the business. Both Kawasaki's.

I really like what you said. “They have not cut quality to increase profits, they have cut quality to compete with other brands.”

I think this holds true of many products and also services in the last 25 years. People love low price and have helped essentially to drive the quality down on both products and service, in general. You often hear people talk about corporate greed etc., but the business owner has to be concerned with gross profit, not the customer.

 

[StarTech]

Yes worn valve faces will cause problems and worn valves should be replaced.

And note that there quite abit of sloppiest in the adjustment screw to the adjustment barrel. I always sneak up closing the clearance adjustment and torque the locking nut to 87 in/lbs. Don't over torque it either. This is keep the adjustment barrel from moving.

As a business I am more concern Net profit. Gross profit doesn't allow for all the expenses. Personally I shoot for a 10-15% net business profit after expenses so I used 20% GPM on items that include shipping and at least 35% GPM on items that don't include shipping. Always having to buy tools and this week a new air compressor. I have been clearing 20-25% Net every year until this year. Just hoping to break even. I having to change to 45% GPM to uncontrollable shipping charges. Even using the OEM price files are not working as they are raising prices on my shop and not the customer thus cutting the GPM to bare minimum. Just can't buy a part for $5 and charge $5.10 for when the shipping is around $15 per order. Buying bulk helps but still I barely making a profit and that is long term outlook on those items.

Right I got two items inbound. Deck screws which JD wants $4.66 ea for (Just for the shouldered screw). I needed 4 of them with flanged nuts but I had to order 20 @ $2 ea. So I will have 16 of them just sitting in storage until the next project. Then there some 6205-ZZ 1 bearing that Gravely wanted $15 ea , I got 20 of them @ $76. Here I will have 14 of them sitting until need again.

 

[bertsmobile1]

I really like what you said. “They have not cut quality to increase profits, they have cut quality to compete with other brands.”

I think this holds true of many products and also services in the last 25 years. People love low price and have helped essentially to drive the quality down on both products and service, in general. You often hear people talk about corporate greed etc., but the business owner has to be concerned with gross profit, not the customer.

Honda made one of the best engines for mowers .
Honda exited the mower engine sector because they could not make a quality engine at the price that mower companies would pay .
Now that should have sent red flags to every other engine maker but no Kawasaki jumped into the hole left by Honda
And guess what ?
They can not make good engines for those prices either .
This is no surprise
Yamaha thought they could do it and found that there was no money to be made & exited almost as quickly.

Again it come down to the small margin on large turnover model that worked in the 70's & 80's till competition from third world countries started which took out the bottom end and volumes dropped .
So yes there can be greater profits overall from small margin - high volume system but it is very dangerous if you can not guarantee sales volumes .
A couple of bad years and you are done for

Now this comes down to the brainwashing that all in the West have been pounded with that we can have whatever we want and it will get cheaper every year because of superiour technologies being introduced
Well millenia ago they know this can not happen but the saying "you can not have your cake & eat it as well " seems to have gotten lost in the mists of time .