Tried to fix a boat anchor!!!!

[MaddBomber]

Got this POS Craftsman 36cc CHITBOX saw to fix for a friend. No compression. Replaced the piston, cylinder, rebuilt the carb, replaced all fuel lines, replaced the crank bearings, and cleaned out the gas tank.... Still won't run right. Holds 15 lbs of pressure and vaccuum for hours. WILL NOT RUN RIGHT.
Starts hard... then after messing with the carb, finally runs, cuts good, idles fine. Couple hours later, saw won't start. Fiddle with carb, get it running.... re-tune it, runs great, cuts great. Let it cool down, starts fine, won't rev. Just bogs out and dies. Won't re-start.............
Fiddle with carb, finally runs, warms up, runs and cuts great..... repeat. I'm out of ideas
Just want to chuck the thing into the woods and have my dog crap on it.

 

[mini kahuna]

I had a husqvarna 136 doing the same thing to me,it would run right for 5 mins and then the thing would throw fits,never did figure it out..I am guessing it had a crack in the case somewhere..it did take a ride into the woods though.

 

[DSS]

I had one giving me fits, kind of the same symptoms, it was a homelite.
Sort of figured out it was the check valve ( non repairable) in the carb.Too much compressed air when I blew it out.

 

[jus2fat]

Don't forget the coil...I've read here on AS that often times that is the problem.
Saw will run fine until it gets hot...then crap-out. Let it cool down and it again runs fine until gets hot again.
I've never experienced it...just have read about it...WFIW..??

J2F

 

[ironman_gq]

tune it to run good cold and see how it works when it warms up. just play with the carb till it starts and revs good and then let it warm up and see if it still runs OK. your friend probably wont notice the difference as long as it runs

 

[JasonBmac]

Wandering tunes are often, as Daddy66 pointed out, caused by bad main nozzle check valves... And they ARE repairable.... You can either use the new walbro parts, or fudge it up yourself on some non-cartridge style ones....

I'm not saying this particular saw suffers from that, but it definately has a carburetion issue, I think....

A bad main nozzle check valve will tend to cause:

Under constant Hi throttle, responds to needle normally, Hi setting may "wander" (a result of the remains of the check disk obstructing the jet)

lean stumble on acceleration, or no acceleration (lean-out quit).

Sick rich (flood-out) on deceleration

No idle, or at least no idle sometimes...

The main nozzle check valve's purpose is to prevent the main nozzle from being sucked dry thru the idle jets when at idle...

J

 

[scottr]

Got this POS Craftsman 36cc CHITBOX saw to fix for a friend. No compression. Replaced the piston, cylinder, rebuilt the carb, replaced all fuel lines, replaced the crank bearings, and cleaned out the gas tank.... Still won't run right. Holds 15 lbs of pressure and vaccuum for hours. WILL NOT RUN RIGHT.
Starts hard... then after messing with the carb, finally runs, cuts good, idles fine. Couple hours later, saw won't start. Fiddle with carb, get it running.... re-tune it, runs great, cuts great. Let it cool down, starts fine, won't rev. Just bogs out and dies. Won't re-start.............
Fiddle with carb, finally runs, warms up, runs and cuts great..... repeat. I'm out of ideas
Just want to chuck the thing into the woods and have my dog crap on it.

My 38cc Poulan Pro wouldn't behave untill I opened up the constricted muffler outlet. Is the muffler outlet constricted?

 

[pioneerguy600]

Wandering tunes are often, as Daddy66 pointed out, caused by bad main nozzle check valves... And they ARE repairable.... You can either use the new walbro parts, or fudge it up yourself on some non-cartridge style ones....

I'm not saying this particular saw suffers from that, but it definately has a carburetion issue, I think....

A bad main nozzle check valve will tend to cause:

Under constant Hi throttle, responds to needle normally, Hi setting may "wander" (a result of the remains of the check disk obstructing the jet)

lean stumble on acceleration, or no acceleration (lean-out quit).

Sick rich (flood-out) on deceleration

No idle, or at least no idle sometimes...

The main nozzle check valve's purpose is to prevent the main nozzle from being sucked dry thru the idle jets when at idle...

J

Yep + 1
Pioneerguy600

 

[Kingsley]

How much were the parts? Why didn't you replace the saw with something better? Just curious.:monkey:

 

[MaddBomber]

Well, the owner told me he really needs the saw today, so with fair warning I gave it back. Right before he took it, I gave the carb a last tweeking and it started hard, but ran good.
The carb was a Zama w/ a strato plate. I'll look into better rebuid kits for it. The kit I got was very basic.
All the parts were $80..... The saw brand new is $125. I tried to tell him to just get another, but he insisted on a fix.
I really hate clam-shell saws. I've been too spoiled with pro models.
I plan on stopping buy this afternoon to check on the saw, and possibly give him a loaner, untill I can get the Craftsman squared away.
He really does need a better and bigger saw. I've seen him bucking some big oak with that little thing. I'll keep my eyes open for a good fixer-upper for cheap money.

 

[scottr]

What model number is the Craftsman saw? Does it have a black or silver muffler?

 

[MaddBomber]

What model number is the Craftsman saw? Does it have a black or silver muffler?

Silver muffler, red & black plastic (jonsered/dolmar style), tool-less chain tensioner..... It's just under 2 years old (November), and the owner's manual had a complete IPL in it, along with the original reciept.
The model number is HUGE LONG, but its a 36cc 16inch bar (can't find them on Sear's website). Engine is a strato clamshell with Walbro stamped on bottom of shell. Has funny crank bearings (first time opening a clamshell), the seals were on the outside of the bearings.... Kinda strange, but bearings/seals were only $10 apiece (cheaper than most pro crank seals). Transfers are ladder-shaped plastic pieces that slide into the cylinder.
Factory carb settings (way lean), and inexperienced operator nuked the top-end. This thing got so hot it boiled the seals off the bearings(atleast that's what it looked like). There was absolutely no carbon to be found. Inside of muffler had a small black spot.... Now it is running rich as can be... as per request.
Over-all it's a strong little screaming strato, and would keep a yuppie with a 1 acre lot very happy....... too bad it's a primary firewood saw for 30 acres (this guy needs a 55+cc saw BAD..... hard to do for under $300) The good news is that he maintains a sharp chain, and a clean airfilter.
If i can get it running right, it might last another couple of years...... might.

These are the junk parts I have left..

Piston ring is very stuck.

Note the wierd plastic transfer plates that slide in

Poor quality pic of the sealed bearings.

 

[2000ssm6]

How much were the parts? Why didn't you replace the saw with something better? Just curious.:monkey:

+1, why worry or even replace parts on such a POS?

 

[MaddBomber]

+1, why worry or even replace parts on such a POS?

:agree2: +2
This is a personal favor to an old family friend. His back is just a broke as his wallet, otherwise I would have sent him to get a better saw. Now it has become a pride thing...... this thing haunts my freeken dreams!!! If it's not running right by next week, I'm gonna buy the ****-box off of him and exact my revenge.

 

[cmarti]

:agree2: +2
This is a personal favor to an old family friend. His back is just a broke as his wallet, otherwise I would have sent him to get a better saw. Now it has become a pride thing...... this thing haunts my freeken dreams!!! If it's not running right by next week, I'm gonna buy the ****-box off of him and exact my revenge.

I had a Poulan Pro that would run hot, but never restart hot. I fought it for a long time as it was a jigsaw puzzle. As punishment to both, I gave it to my brother in law....