EVO Engine Cam Change Major problems

Discussion in 'Engine, Fuel and Exhaust' started by patxa, Oct 13, 2009.

  1. patxa

    patxa Member

    Hi all,

    Just thought I would run this by you all see what you all think ??

    I have an 1987 Softail Evo After purchasing a chrome Cam cover and set of rocker boxes.. I decided to have them fitted by the Local Custom Hartley Shop rather than attempting the job myself.

    When they pulled it down they told me that the cam in the bike was only a Andrews EV1 Grind. They advised that the EV3 would be a good upgrade while everything was apart. .. Long story short..I got the bike back and it ran like a dream better power etc etc.

    The next day I took it for a ride. About 80 miles into the ride while coasting down a windy mountain road, on deceleration I heard an loud Backfire .. BANG and the engine stopped. In trying to start the Bike I immediately noticed that it was turning over very easily like the engine had lost compression.
    (Normally the Starter would labor to turn over the engine )
    The engine would not fire at all.. Not a whimper. Plenty of spark and fuel but no one kick

    So today took the bike back to the shop. They first checked over the work that they did and advised me that all looked fine, Timing marks were in order rockers fine everything turning and lifting and closing fine. However compression test only came up with about 25psi.

    So they Pulled the heads off. Pistons ok, Piston to bore clearance within tolerances, no visible case cracks or oil leaks etc. The only thing they could find was the valve seats did leak slightly. ( Apparently they fill the chambers with some fluid and check for leaks ). Valves were not burnt out or bent just the seats looked carbonized and leaked slightly.

    They are now suggesting that they are going to lap the valves and fit a new set of Hydraulic lifters and put it together.
    They believe that all will be fine. The suggestion is that perhaps the lifters were hydraulic-ing whatever that means.

    Is this at all likely..?

    I cannot understand how this engine which until this happened ran fine and seems to have plenty of compression one day. Lets out a awful Bang Backfire and then has no compression and no obvious reason for the lack of compression.

    Can anyone help
  2. Hoople

    Hoople Account Removed

    It really would have been nice if they had done a cylinder leakage test. That would have told them immediately where the problem was. But that is behind you now.

    Was the compression that low in BOTH cylinders.

  3. Fossil

    Fossil Active Member

    Any thing can happen and there are others on here who can answer you questions better than I. The Andrews EV3 is a midrange, stock valve springs with stock hydraulics. Has your push rods been modified to adjustables? Usually shops like to just cut the stock ones out and put in adjustabes. If they are adjustable then possibly the adjustment was too tight and as the bike pumped oil and got hot some thing got suck open. On my 1988 EVO I have an aftermarket performance cam and took the adjustable push rods out and put the standard ones back in. To me that is just one less possible problem. Fossil
  4. patxa

    patxa Member

    Yes Apparently the engine had only 25 pound in both cylinders. I know the compression was down because it turned over a lot easier then it did previously. It was always a hard engine to crank prior to this issue.

    Also the pushrods are adjustable. I guess i am in the hands of the mechanic as to if he had the pushrods adjusted correctly or not.

    I still find it hard to believe that one minute compression and running and the next minute low compression not running and nothing mechanical is wrong???

    Can ignition timimg affect compression ?????
  5. Flashback

    Flashback Active Member

    Only to the extent that if is out so far that a valve is still open on the compression stroke then yes it would dramatically reduce it.
  6. patxa

    patxa Member

    The repair shop is still saying that they are going to re seat the valves and fit new hydralic lifters and put it back together.

    They seem to be blaming the cyl lifters

    I keep wondering if i am getting dudded

    Yes compression was the same on Both cylinders ( About 25 psi)
    They have done a leak test on the valve seats and say that all the valves leak slightly.
    They want to relap the valves and throw a new set of lifters in the thing.. Something about the lifters hydralic-ing ..
    Last edited by a moderator: Oct 13, 2009
  7. Hoople

    Hoople Account Removed

    If the lifters were "pumping up" that would release the compression. Your Compression readings would be very low. Re-lapping the valves ALONE will not fix the problem. Relapping the valves in ADDITION to fixing the real problem is great. To test their theory, all you would have to do is temporarily increase valve lash by .020" and recheck compression. If it IS the lifters, the compression will pop up to normal. Ignition timing has Nothing to do with compression. Cam shaft timing does.

    My opinion is they are trying to make it look like "something just happened" that had nothing to do with the work they did.
    Research how hydraulic lifters really work so you understand what "pumping up" means and how hydraulic lifters control valve lash & noise. You will then see & understand how a pumped up lifter will relieve compression.

    When they installed the new cam, did they install New lifters? If they didn't, they should have. If they did, then the problem you have should be covered under any warranty they have on their work.
    I may be jumping the gun which is not fair, but get your bike fixed and don't go back to that shop. Anyone who can not test for pumped up lifters relieving compression is not someone who I would want working on my bike.
    But that is just my 2 cents.
  8. Jack Klarich

    Jack Klarich Guest

    Have them check the lifters easy check and easy fix evos hac lifter problems that could explain the compression problem too tight no compression and or bent valves too loose low compression no power

    BUBBIE Well-Known Member


    The lifters were NOT adjusted properly at the shop....

    BOTH cyl's were low on compression,, RIGHT

    BOTH cyl's were low because the lifters were adjusted WAY too tight... ie causing the problem.... NOTHING ELSE....

    I WOULD agree not to use that shop for ANY repair again...

    I would BET I'M RIGHT ON about the problem and SOLVE...


    A simple ck to see IF the adjustable pushrods were LOOSE enough,, turning easily when valves were CLOSED should of been the TRICK.... NOT tearing into the heads blindly... I believe there should be NO CHARGE and as far as letting them touch-up the valves???....there was NEVER THE NEED TO TEAR INTO HEADS : "so while they are in there": that means your gona pay!!

    The lapping of the valves is great to do "while in there" but NOT to charge you for it is a small price for THEM to PAY YOU BACK for their lack in ability to trouble shoot the problem correctly......

    NOW THAT I SPOUTED-OFF..... hope I'm right.

  10. Hoople

    Hoople Account Removed


    I agree 100% with you Bubbie. It drives me Crazy when I hear stories like this.
    I wish someone would pay me $75/ an hour to correct my own work.

    Bubbie for President!

    The Hoop!