What's on your bench today?

[Maico490]

you can do vacuum tests as well but not got round to that

 

I use a cheap bike pump with the seal flipped over so it sucks instead of blowing. The proper Stihl tool resembles a large syringe but the ones I've tried from agricultural suppliers are a bit sticky when working dry. You only need a couple of pumps to get 7psi of vacuum on most small saws. I've got exactly the same Draper gauge you show in the earlier pics which seems to work well. For a non return I "doctored" the spring on a screw in type tractor valve but always clamp the pipe close to the tee to take readings.As you stated pressure is quickest to find major problems but apparently some dodgy crank seals only show up under vacuum.

[spudulike]

The majority of crank seals I have found have been completely gone with only the metal spring band being left - amazed people still run their saw when the idle is that bad.

 

This was an interesting one - http://arbtalk.co.uk/forum/members/spudulike-albums-stihl-066-picture3932-deformed-crank-seal-previous-rebuild.html

 

Look carefully and you can see the seal has been turned inside out when it has been replaced - by a dealer and not by me I hasten to add, I got it once it had gone bang! Not much of a leak but enough to ring alarm bells and find the fault:thumbup:

[Maico490]

I've come across lots of people who are none too happy with work done by dealers. Trouble is it costs nearly as much to put someone to work on a small engine as it does on a £20k car. As a result most try to convince their customers to buy new where there is a known margin and the warranty slopey shoulders the responsibility back to the manufacturer.

[Megatron]

So Megatron what is this patented cocktail or would you have to kill anyone you told. I have had little luck in getting hold of decent strength hydrochloric acid. Most of the patio cleaner sold wouldn't hurt you if you put in on your fish and chips. I've been using some industial toilet cleaner which has a reasonable HCl concentration but some other things added.However the label has faded too much to be able to read. I normally heat the cylinders first on top of the Rayburn then take them outdoors to treat. The heat definitely helps with these weaker acids.

 

 

I use caustic soda (sold as drain/heavy duty cleaner), available in most supermarkets/hardware stores etc. As I understand it is virtually pure Sodium Hydroxide (NaOH) and comes in solid flakes/pellets. Mix with water yourself when needed. I haven't got an exact ratio but usually try to dissolve as much as possible in a couple teaspoons of water. I apply with a small synthetic brush (The end of Q-tips seem to dissolve).

 

Heat definitely helps. I can't compare how good the Caustic Soda is compared to acid as I have never used it.

 

Disclaimer: I am in no way recommending that anyone try this. Just outlining what I use fully understanding the risks involved.

[Maico490]

Thanks for that Megatron I'll try some. Now I think about it the alkaline cleaners we used to use on dairy equipment would eat an aluminium milk churn through in no time.

[bob]

does anyone fancy a 394 seize on their bench

still pulled over but rings seized in and bore damaged:thumbdown:

[spudulike]

does anyone fancy a 394 seize on their bench

still pulled over but rings seized in and bore damaged:thumbdown:

 

What about a picture - has the cylinder been removed yet? If not, pop the muffler off and lets have a look:thumbup:

 

Thats one expensive saw, we can rebuild it, we have the technology to build the worlds first bionic saw:001_rolleyes:

[tommer9]

The tipping gear from the landrover......it has 10 + years of grease and grime in it and has (very suddenly bizarrely enough) lost all it tipping power.

Well actually its not on my bench anymore, its on a rotating electrics guy's bench for £40 for a pro clean.

[bob]

carb side is ok

thoughts

I do have a gasket set:thumbup:

[spudulike]

From what I can see, the bore looks fixable, in fact it looks much cleaner than the MS880 that I cleaned earlier in this thread, that must have had around 0.1mm of aluminium transfer on the bore and looked much nastier.

If you want it done - PM me!