084 starts and dies within seconds

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torch

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I think I've been infected by you all. I'm starting to collect chain saws now...

I picked up a nice clean looking 084 this weekend. ("It just followed me home, honest dear..."). It was reputed to have had very occasional use and the appearance supports the claim. 3' B&C, + 2 spare .404 chains to fit it. It feels like it has excellent compression (especially if one neglects to push the decomp button! :oops:). I put some fresh fuel in the tank, full choke, 1/2 a dozen pulls and it fired up. Choke off, pull again, fires right up and runs for 3 to 5 seconds. Won't restart without choke, but then will act as above.

Alternatively, after priming with the choke and releasing the high-idle, it would start and run for slightly longer at idle. For those few seconds, it revs and accelerates freely when I pull the throttle, but bogs and dies very shortly thereafter. Fuel and air filters look clean, tank vent hose seems unobstructed (I even tried running with a loose gas cap -- no difference)_

After adding a bit of extra oil to the mix, I tried hitting it with a short blast of quick-start as it bogs and dies. The QS brings it back, so I'm pretty certain this is a fuel problem. I added a heavy dose of Seafoam, backed out the mix screws another 1/4 turn and ran it a bit more to work the Seafoam into the system. The saw actually seems to be running longer now, but that may just be because it eventually warmed up enough.

My personal motto is "Hope for the best, but plan for the worst." While I've seen Seafoam work miracles, I suspect there may be a carb kit in this saw's future. From the serial number, this saw is an early model, and from the wealth of data I was provided in the Beg for Manuals thread, it therefore likely has an CDIC ignition module and HT1 carb.

Looks like carb kits are still available, as is the fuel hose. The impulse line may be a problem though. Is there a universal tube that would be suitable for use as an impulse line?

Do the symptoms ring any bells with 084 owners? Anything else I should be looking at?
 
Baileys has your impulse hose. You should be able to get it for 11 bucks or so from your dealer. Same one as an 088/MS880

Baileys says "ships in 12 to 14 days". Which is internet speak for "we don't actually have one to sell you, but our supplier has not removed it from their computer inventory yet, so we'll bill your credit card now and refund you in a couple of weeks if the supplier can't actually provide us with one".

But thanks for the info about the cross-over between the 088/MS880 and 084. Anything that crosses to a current model should be available from the dealer. I have no idea what I will ever do with a saw this big, but I'd like to get it running right nonetheless.
 
Crank seals are likely gone if the impulse hose is intact. The resulting air leak disengages the carb's ability to send fuel to the engine. The impulse hose can actually be replaced with good Tygon fuel line. I've done it several times with success. But, that fails if the crank seals are leaking air. Unfortunately, to replace those seals on an 084, you have to split the case.
 
Brad and Gary nailed it: impulse line. It's in two pieces, broken clean off where it passes through the tank housing.
 
Update: Nothing wrong with the impulse line. This saw has a two-piece impulse line, unlike the parts diagram I snagged. The fuel tank/handle casting incorporates a hosebarb type coupling to join the two halves. The piece between the cylinder base and casting had popped off. I reconnected it and the saw runs great now after some minor tuning.

I never had a saw with .404 chain before. Boy does it ever fall through a log.
 
Update: Nothing wrong with the impulse line. This saw has a two-piece impulse line, unlike the parts diagram I snagged. The fuel tank/handle casting incorporates a hosebarb type coupling to join the two halves. The piece between the cylinder base and casting had popped off. I reconnected it and the saw runs great now after some minor tuning.

I never had a saw with .404 chain before. Boy does it ever fall through a log.
The 084 is a true classic. At a GTG a few years back I was eventually nipped by a guy running a Husky 394 that wasr running a skip tooth chain, muffler mod, and mixed airplane fuel. Until I ran against him, I had outrun all others there. We were both using 36" bars and cutting a big log. I was using typical .404 full chisel chain. He told me no stock saw had ever beaten him and he was impressed with my 084. I sold that beast but sometimes I think I should have kept it.
 
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