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bmp01

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Posts posted by bmp01

  1. 4 hours ago, Gordon S said:

    Hi,  my dad had the Florabest corded Chainsaw (he loves a Lidl middle isle bargain!!) 

    It had plenty of power and he really liked it, I thought the quick tensioner was a bit weak. It had a good 3 or so years of abuse cutting worktops/nail strewn batons and pallets. It was left in a leaky woodshed all year round and eventually the power cord parted from the body. It was great for the money paid.

    Thanks for that, there's one going cheap nearby might be worth a punt then.

  2. Can you come up with a way to drive the oil pump without the clutch in place or engine running?  I'm thinking battery drill and an adapter or rubber drive drum (like the rubber drum you have in a demel kit for the sanding drum). Blank off the outlet to the bar, as youve done already. Spin the pump and look for leak. ...

  3. Yeah....but....

    The outside of the bar is what it is. It's the inside working bearing you need to see but of course you can't. The only thing you might gleen some info from is the sprocket (not the nose assembly but the actual sprocket), so chain off and inspect down to the root of tooth form. Look for coloured steel indicating heat.

     

    I'm guessing your planning on running it anyway.

    1) Cross cutting would be a safer way to assess the nose sprocket assy and build confidence.

    2) Your milling attacement is still too close to the nose bearing IMHO. There is a void just back from the bearing, where the sprocket teeth would run. CIamp into solid metal back from this void.

     

     

    • Like 4
  4. Think I'm with adw on this, the metal bits that are made hard in manufacture by heat treatment have most likely been re-heat treated - meaning they will now be softer than they should be and not last.

     

    The scortched paint tells where it got hot. The thing to note; its not just hot where it was pinched .... I'd say the (nose) sprocket itself got hot and subsequenly transferred the heat to the near by bar, hence the circular pattern of scorched paint. For the little sprocket to put that amount of heat into the relatively bIg bar I'd say it got very hot. And if the sprocket got hot so did the needle rollers, these are (were ?) both hardened material parts.

    If you take the chain off and clean / degrease the nose spocket can you see if it has gone blue ?

     

    Edit: heat pattern is inboard of the nose sprocket, looks like it matches with where the rolling bearing is....

    • Like 2
  5. On 18/04/2022 at 14:10, openspaceman said:

    Would the top stratification choke tube with the purge line fit the new carb?

    So swap the old 'top half' on to the new non purge bulb 'bottom half' ? That'd work I think and not much to go wrong with 'top half'.

    Think I'd ditch the purge bulb if new was the only option. But just fix the old carb, such a waste and expense to bin it. 

     

    • Like 1
  6. On 15/04/2022 at 10:10, Darkslider said:

    How do you go about diagnosing an accelerator pump problem? I've had a few saws where everything else has checked out but it still bogs when revving so as a last resort I've fitted a new carb which has cured the problem, however it's always felt like a lucky guess so far I'd like to know for sure how to pinpoint an internal carb/pump fault?

    A nice tell-tale, if you are prepared to do a bit of disassembly, is to drip some Redex into the accelerator piston hole behind the throttle shaft and see if you can suck it into the hi speed circuit. I tend to blank off the drillings in the metering chamber with blutack, remove hi speed screw and suck through there via soft tube. Any time you see red coming through the carb you know the accelerator piston seal is leaking.

    • Like 3
  7. On 30/03/2022 at 15:28, openspaceman said:

    A little update on the MS181C I was having trouble diagnosing a misfire on.

     

    I took @bmp01 up on his offer and finally got the saw to him on Friday. By the evening he had sussed out a number of faults, the coil gap way too large, purge bulb pipe not fitting properly and the biggy was the accelerator pump piston. By Saturday it was ready for collection with a modified carburetor and arrived back to me yesterday. Here it is cutting some wood immediately after running it 10 seconds from cold. I have now ordered some parts he suggested should be replaced before taking it back to the lady owner.

     

    @bmp01 may explain the detail better.

     

     

    No worries, pleased to be able to help :)

    • Like 1
    • Thanks 1
  8. Thanks for posting your findings and well done in doing the comparison between good and bad carbs, you have some certainty there. 

    So, these valves can go wrong in a range from the working parts 'just get stuck' through to parts completely missing. The latter is often the result of high pressure air being blasted through the adjuster screw holes.

    There's a chance you can resurrect a 'just stuck' valve with carb cleaner, petrol, etc or ultra-sonic cleaning - basically you are just freeing up a tiny disk that 'floats' in the valve. Remove the  low speed screw to access.... start with low pressures and progress, not much to loose at this point 😈 😨

     

     

  9. 4 hours ago, Hunter said:

    Picture is for the working carb. The other carb Seen in picture to the left.

     

    Ok, I hadnt realised that, apologies. 

     

    The point about the purge bulb pulling in air is still valid - it shouldnt do that. As stated before either hose fit on the purge bulb fittings  is loose or the bulb itself is leaking. Always worth fixing things like this before they create a problem or symptoms you don't understand. ... 

  10. I'm confused by your experiment and statement that its not sucking fuel.

    I see fuel and air bubbles in  the return line. So it must be sucking some fuel through the carb, no ?

    I don't see any air bubbles in the line between carb and purge bulb, is that all fuel?

     

    Edit: Looks like 100% fuel in the line between carb and purge bulb. I agree with Openspaceman, you have an air leak around the purge bulb, might just be a loose fitting hose on purge bulb, or a cracked leg on the purge bulb....

  11. So you've got 2 fuel circuits in the carb, a low speed and a high speed.

    Low speed circuit is fed via the bung in your blue circle and there is a little flap check valve on t'side. 

    High speed circuit is fed via the small hole below the main jet / check valve assy.

    If you have a piece of small dia hose, preferably soft silicone, you can hold one end over the entry hole and blow / suck to confirm the check valve operation. Adjustment screws need to be NOT bottomed out. Low speed circuit will flow a lot less than the high circuit.... 

     

  12. 2 hours ago, spudulike said:

    Not nice!

    No it isn't. 

    I didn't spot this from the pull cord compression test,  held its own for over a minute. 

    Compression test was 135 psi - low for sure but I passed it off in my mind because I had to use 10mm adapter for the gauge. 

    Aw well, you win some, just not this one. 

  13. Sorry for the delay, that 201 (up the page somewhere) isn't going to run right for a little time yet. Needs a piston that measures a bit more than 39.70mm across the skirt. Probably explains why the idle screw had to be wound in some to get it to run. Cylinder has cleaned up surpisingly well.

     

     

    20220222_200535-1.jpg

  14. 11 hours ago, peatff said:

     

    Join the two pipes to the purge bulb or block them both off but it sounds like you need to replace it.

    Yeah, block them both off if you have concerns about the bulb. It's not necessary to run the saw. 

    If the one way valve in the bulb isn't working 100% then the carb sees tank pressure which definitely upsets the apple cart. 

    Also, just check that release of tank pressure you mentioned in post 1 was positive pressure and not vacuum.... hard to tell difference in sound between gas coming out or going in. Of course, if the fuel cap popped out .... :)

    • Like 1
  15. On 12/02/2022 at 16:35, spudulike said:

    I would avoid using an unknown seal type as I have seen pistons stuck in the bore and have had to drill them out and pull them out with a screw! The piston spring is a low rate and if the piston is too tight, it will get stuck in one position and makes for poor performance off idle!

    T'is a risk.

    Care to share details of std seal, is there a part no ? I've looked on 200t parts list but no joy there. 

  16. Yeah, I agree regular sizes would be preferable.... the original oring is a little over 1.0mm section I think (hard to be sure it's degraded and changed shape etc). Wouldn't be hard to machine up a new piston to take 1.0mm section Oring but at that stage might as well just buy new from Stihl.

     

  17. 2 hours ago, spudulike said:

    I think you will find it is the same as the MS200T...pretty sure of that!

    Thank you ! 

    Ever tried replacing just the O ring ?

    Piston groove: Dia = 3.17, Width = 1.20    Bore in carb 5.0 

    O ring with ID 3.0, Section 1.1 Viton material would be about right.... probably unobtanium.

     

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