Stihl FS90 needs Short Block

Discussion in 'Mechanic and Repair' started by MisterBreeze, Sep 18, 2013.

  1. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Messages: 852

    Isn't the FS90 a four stroke?
  2. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,588

    The Echo 265 has been very reliable in the field. I have 10 and the oldest set is probably 6 year old and heavy use. They do have high and low needle setting. Many people come on this site with problems I know are carburetor, if no adjustment then what? I used to run Stihl but stopped when 4mix came along. Thankfully I didn't buy any 600 units that basically knocked Stihl out in our market. And I can easily get parts when needed. I take Echo units from dealer that sieze due to no oil, and get them running. Part hobby but make good backup for our business.
  3. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Messages: 789

    Yes, the FS90 (current model) is a 4 stroke OHV hybrid engine that still uses a 50:1 mix.

    Hmm, I thought they used rotary carburetors that just had a high speed screw (with a limiter cap over it) and an idle speed screw?

    For the most part, the only carburetors that Stihl has used that were non-adjustable were the BIS carbs on some models... Idle speed adjustment only.

    Those BIS carburetors have been discontinued and they reverted back to an "semi" adjustable carburetor on most if not all current models. However, due to EPA regulations that ALL OEM's have to comply to they now have either a limiter cap with some adjustment of low and high sides... Then there are the different versions of "tamper resistant" low and high sides that require special tools to adjust. Thank your EPA for that!

    Has Stihl had different issues through the years?... You bet! Just like any other manufacturer out there. Being a Stihl Dealer, I have seen it all and also seen Stihl go WAY above and beyond to help customers with repairs that were well past their warranty period if it is a known issue and made it up to the customer... Perhaps, the dealer makes a difference in being willing to help go to bat for the customer also!

    There is no local Echo Service Dealer in this area, and to my knowledge there hasn't been one in moons, but we keep getting people that buy the product at HD and need parts or repair... Sucks to be them!

    I have never had a problem getting parts for any Stihl product as long as they were not NLA...

    To each is own...:)
  4. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,588

    Keep hearing about the end to 2 stroke but each year they are back. Apparently most Echo dealers don't know about even one adjustment . And yes there are 2 adjustment needles.........
  5. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Messages: 789

    Is it a rotary style carburetor?

    Same here, been hearing 2 cycles would be gone by XXXX. Well, XXXX is long past... It is only a matter of time though before they will be gone due to the EPA!

    Going from 2 stroke to 4 stroke is just the beginning... There will be much more in the way of EFI coming too!
  6. MisterBreeze

    MisterBreeze LawnSite Member
    Messages: 104

    Sorry I have not been on this website to respond to "why it needs a short block".

    I was told it had something to do with the valves not being able to hold the specified adjustment. Something was worn out. I guess I was so shocked as to the price of repair I didn't hear the entire explanation.
    Posted via Mobile Device
  7. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Messages: 789

    With that being the case, it is most likely due to the pin that the cam rides on has egged out the boss on the block side. In which case could be confirmed within a matter of minutes... If the bosses on the block and the cam cover are ok, then the lobes on the cam are worn and is easily repaired and inexpensive.

    Attached Files:

  8. dboyd351

    dboyd351 LawnSite Bronze Member
    Messages: 1,126

    Is that why we wanted valves in these things?
  9. sjh71

    sjh71 LawnSite Member
    Messages: 1

    I work at dealer we use a quick assessment. if unit needs new head Throttle cable and carb or bad leak down or crankcase pressure leak is a defiantly not worth fixing..sounds like it has a bad exhaust valve,
  10. Jeff in AL

    Jeff in AL LawnSite Senior Member
    from Alabama
    Messages: 789

    Huh? Perhaps I have not woke up enough yet to understand your comment???


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