Power loss on 25HP Kohler

Discussion in 'Lawn Mowing' started by John DiMartino, Sep 10, 2000.

  1. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    My 25hp Kohler has run great since the headgaskets were done about 2 months ago,but today it feels like it lost about 5-8hp all the sudden.There is no smoke like last time,I will do a compression check tomorrow am,is there anything else that'll make it weak?Its only got 125hrs on it,I checked the air filters,they are like new yet,i popped a new fuel filter in it,the decks clean,any other tips would be appreciated(besides trading it in)I still have 30 months of payments I hope it lasts that long.Its on a 2000 DC XW2500,my governor is set at 3760 with blades on.It drops to 3500 easily now and i have to slow down or bog.
  2. landscaper3

    landscaper3 LawnSite Bronze Member
    Messages: 1,354

    When you blew the gasket and replaced it did you plain down the head? If those heads get hot they sometimes warp a little.
  3. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    Dealer did it,they put sae30 in it too,I doubt they planed the head because it was done in under 2 hrs.I really regret buying this engine.The original gaskets that blew were the updated ones thatwere supposed to fix the problems,they just put in another set of the same ones that came off,im not sure if they used new bolts too.

    [Edited by John DiMartino on 09-11-2000 at 01:25 AM]
  4. landscaper3

    landscaper3 LawnSite Bronze Member
    Messages: 1,354

    90% of the lawn companys up here run Walker mowers due to Maine has thick grass and looks like crap when its discharged and Fall cleanups, any ways the kohler engines up here range from 1hr to 3000hrs no rebuilds but talking to the Walker distruter he says that his dealer average around 2000hrs up here on those kohlers. We also use them in winter to plow and throw snow
  5. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    With the chunk of headgasket in my oil for 9hrs,i dont expect it to last nearly that long.There was a piece of gasket about 1" in lenth and about 2/3" wide that got blown into the exhaust pushrod passage,that goes to the oil pan,so im sure tha if i tore doen the engine the bearings are scuffed and scored,then kohler would try to deny it,so im not even bothering,when it pukes out of warranty ill put a kawi in or whatevers better by then.I dont expect it to last more than 500hrs
  6. landscaper3

    landscaper3 LawnSite Bronze Member
    Messages: 1,354

    were the valve checked for damage?

    BUSHMASTER LawnSite Senior Member
    Messages: 519

    i would have the bolck and heads check for strainghtness,also might be a good idea to change the head bolts since there prob tourqe to yeild anyway,springs,locks.rockers,valves,lifters,never hurts to look.
  8. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    I wasnt there when he did the work,i doubt anything was checked,i think it was a simple R&R gaskets.When i bought this new it didnt use a drop of oil for 66hrs,it popped the gaskets and used 1 1/2 quarts in the 9 hrs i used it before they did them,ever since i got it back its using some oil still,about 6 oz in 50 hrs,thats 6 more than it used before the gaskets blew,si i bet the cylinders got scored too.
  9. Keith

    Keith LawnSite Gold Member
    Messages: 3,979

    Man, this really sucks that so many people are having problems with these engines even after the supposed fix. On one hand you have mower manufacturers who can't control Kohler, but rely on them heavily to supply power. On the other hand you have Kohler who would rather fix your problem than replace an engine, even if it takes multiple trips to the dealer to do so. And then you have the end user, who has countless payments left on a machine with an engine that is completely unreliable. Paying this much for these machines, you would think, would give you years of service without failure.

    I truly believe the problem with these Kohler engines is their 9:1 compression ratio, teamed with only air and oil cooling and a lot of times only 87 octane gas. They must truly be running on the ragged edge of detonation constantly. I only run synthetic oil in mine in an effort to get the operating temperture down...even if it is just a few degrees.
  10. MOW ED

    MOW ED LawnSite Fanatic
    Messages: 5,028

    I agree. Kohler may make some engines that run for many hours but the 25hp that I had was made in hell.
    My gaskets went like yours John at 120hrs. It was a great mosquito fogger. From there I had constant problems from coils to wires to sending units to intake gaskets. I finally got it fixed and sold the unit at about 650 hrs.

    Kohlers policy on not replacing these anchors really sucks.

    I can see trying to fix it at problem #1 but to continue to try and try gets to be a big mess. I think some of it was my mechanic. He was a Kohler certified mechanic but it didn't seem like he had a good handle on what was happening.
    Basic fixes are like band-aids on a bleeding artery.

    I am a small operation and yes, when I replaced the 25 Kohler I bought a 26EFI (it takes me a while) but I do have the warranty and so far so good. But in the future it will be diesel. Good Luck

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