262xp starting problem

woodworkingboy

woodworkingboy

TreeHouser
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Aug 16, 2008
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An older saw but in overall very good shape. The saw starts up fine when cold, but after running a bit then shutting it down and waiting a minute or two, it won't restart without the throttle being pulled at the same time. I cleaned the carb, the diaphragms are in good shape, throttle and choke linkage and idling adjustment is good, the choke lever works as it should, and when it's running, it runs well. The plug spark seems good when it doesn't want to start, first I was thinking that the coil might be going out giving a weak spark. I'm assuming it's a fuel problem in the carb somewhere, maybe I need a new carb? If I wait a half hour or so, it starts normal.

It's got me befuddled. Any thoughts appreciated. Thanks in advance.
 
What plug is in it?
When it no start is plug dry or wet?

If it isn't sparkling plug is wet, if it starves for food it is dry.
 
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  • #4
Magnus, it uses an NGK BPMR7A, I think standard for that series. The same as in my 242xp. I switched plugs around, so it doesn't seem to be a plug issue. The plug seems sufficiently wet when it won't start, and it does want to kick over, fires very briefly over a number of pulls, but won't completely start. Pull the throttle and the starter rope at the same time and it starts right up.

Breather...cracking the fuel tank cap open doesn't solve.
 
Does it have good compression?

Not knowing much about chainsaws. Crank seals be a problem?

I have an old pro mac 850 that would not start well, I adjusted the low speed screw and it started well after that. Same as yours, had to hold the throttle open.
 
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  • #6
Compression is good, Jim, I pulled off the cylinder to take a look when I wanted to put the saw back into service. I thought i may have fried it during earlier use. One scored line on the piston, but the ring and cylinder are good. Crank seals I haven't wanted to consider. It does run very well, just that starting hitch. The old saws you often had to engage the throttle lock to get them going, this one reminds of that. A smaller saw i wouldn't sweat it, but kind of on the larger size to be throwing it out there pulling the rope and trigger at the same time.
 
My 262xp was doing the same thing... it's been sitting in the tool shed for the past year... maybe once the shop is finished being built I'll get back to it.

Also the 2100xp and 282xp that need attention, too!

The foundation walls and floor are in, if the rain abates some I'll get the drainage perf-pipe in and backfill, so I can start framing before it gets too cold.

ShopFoundation.JPG
 
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  • #8
I tried tweaking it a bit, raised up the metering lever in the carb a tad to try and get more fuel in the cylinder for starting. No go, I reset it back to the spec. One thing as a result, I can take the carb off and linkage disassembled in like two minutes now, probably with my eyes closed :|:
 
It could not possibly be timing could it? I am not much of a 2 stroke mechanic!

Hard hot start.............Armature air gap? Poor coil? I guess you checked all the lines.

One of the fastest ways to get fired by grandpa was to shut one of the old combines off at any time during the day. The old Chrysler sixes would not start until morning!
 
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  • #10
It does get decent spark, Jim. I cleaned between the flywheel mags and coil contact. I've been tripped up by bad coils before, not sparking when they get hot.You wouldn't know it when cold. I'm not familiar enough with a carb to know what part of it could be bad to cause, besides the obvious stuff to check. I almost never find a saw to be self healing.
 
Hmmmm, the only thing I ever had to do was fiddle with the L screw.

Must be something to do with the carb like you said. I wish I knew more about the darn things. Not a tiny crack in something that opens more when it gets hot? Impulse line?

Where are all the chainsaw mechanics tonight?;)
 
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  • #12
I tried all kinds of different H and L settings, thought maybe it needed more rich. Nope. I put in new intake gaskets as well, one on each side of the manifold thingy. Impulse line is clear. Some little devil in the carb, I reckon.
 
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  • #14
It was a big tree with lots of grit in it dulling the chain. i ran it past way hot and it wouldn't start again. I thought damage must have occurred, and looking through the exhaust port, i saw the line on the piston. I don't recall running a compression check. The saw has just been sitting since then until i got ambitious. If there was damage as a result of that use, it is minor.

I wonder if there could be a leak around a carb welch plug, I did have that occur in another HDA series Walbro, also what's on the 262, but i don't recall how the leak manifested before i sealed it. Where is magman when you need him?

I know very little about crank seals, besides sometimes they go bad.
 
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  • #16
Rajan, I wouldn't bet against that analysis. With some use today, i noticed that the idle does tend to be a bit erratic, like there is a leak.
 
If plug is wet something isn't right.
Usually it has to do with the sparkling parts. I don't use "R" plugs in these saws. They don't like them. I put in several hundred Champion CJ7Y (not RCJ7Y)

Is it fresh fuel, good oil in correct mix?
 
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  • #20
Fresh gas and my usual mix ratio and good oil brand. My other saws are running the same batch with no problems. I should do a carb leak test. Magnus, what happens when a welch plug has a leak? Thanks. I wish I could get another carb to stick in there. The problem kind of reminds of a similar situation that I had with a Zenoah. A carb replacement solved that.
 
A carb kit might be the answer but then again I am no saw wrench. When I have a saw that is going funky I check all the rubber boots and hoses maybe a diaphragm is cracked.
 
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  • #22
The carb kit parts are good, I'm thinking something might not be kosher in the body of the carb. I didn't put in a new welch plug, that's all. I think a welch plug leak makes for rich running, not the current problem.
 
Jay, do you have a way to vac/pressure test? I'd bet on either a pinhole in the fuel line, or a slight air leak somewhere.
 
  • Thread Starter Thread Starter
  • #24
Hmmm....the fuel line looks good but I hadn't thought to consider a pin hole. The line is fairly old. I have been wanting to make cover plates for the ports to do a vacuum test, but never can get around to it. I think your advice is well taken and others that mentioned, try to pursue the problem as a likely air leak. Thanks.
 
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