Ms 200t running issue

[D&S]

HELLO EVERYONE, i am hoping y'all can help me with an issue with my 200t.

ok here goes. the saw starts and runs and idles well most of the time but the engine breaks up in the cut and it will run fine until it has a 1/4 tank of fuel left and then it bogs when i try to give it gas it's like it is starving for fuel and starts to die out even though it has fuel. sometimes if saw is left ideling for a few mins. when i go to give it gas it hesitates and i have to feather the throttle and then it picks it back up. also once in a while when i try to start saw cold with choke it wont start i will leave it sitting for a few mins then it fires up with no choke almost like it was flooding out. these are the problems.

now the info. the saw was recently rebuilt with a factory p & c new crank brgs and seals new intake and impulse line, when saw was assembled it was pressure and vac tested and it is as tight as a drum. i replaced the carb with a new non accelator pump style and i have been running it for a little while with these problems. it also has a slight muffler mod. one thing i noticed though is that for this thing to run right i have the carb settings turned out twice as much as factory specs. whats up with this? i am going to re pressure test to check for any leaks to rule that out but this is a strange one. i did all the work myself and i have modified several saws and rebuilt quite a few with stellar results but this one has me stumped and i had my buddy look at it who is a mechanic and he is scratching his head.
i hope with all the knowledge on this site y'all could help me please. thank you in advance.

dan

 

[Dan_IN_MN]

When the saw is acting up, can you stop and fill the tank and everything is fine?

Have you checked the vent for the fuel tank?

Is a vacuum developing in the tank?

Is the fuel pickup in the tank allowed to go to the bottom of the tank?

You say you rebuilt the saw……was the saw doing this before the rebuild?

What is the condition of the fuel line?

Is there a crack or a hole in the fuel line about a 1/4 of the way up in the tank?

 

[oscar4883]

Check the tank vent as already mentioned. The older style vents where more prone to clogging than the newer style ones IMO as well. Sure it is not a junk carb?

 

[D&S]

yes when its acting up i can refuel and keep going. as i mentioned before the engine breaks up in a cut at wot. carb is new. i have opened fuel cap and it makes no difference

thanks

 

[D&S]

before the rebuild it run like crap the cyl was all scored. after rebuild it had the accel. pump carb and wouldnt run right. i put new carb on and it ran much better but it has developed these problems.

thanks

 

[RAMROD48]

before the rebuild it run like crap the cyl was all scored. after rebuild it had the accel. pump carb and wouldnt run right. i put new carb on and it ran much better but it has developed these problems.

thanks

Carb is still lean...

 

[parrisw]

Check fuel line for pin holes.

 

[tallfarmboy]

Check fuel line for pin holes.

x2

 

[Dan_IN_MN]

yes when its acting up i can refuel and keep going. as i mentioned before the engine breaks up in a cut at wot. carb is new. i have opened fuel cap and it makes no difference

thanks

Check fuel line for pin holes.

Fuel level gets below the hole in the fuel line.

 

[a. palmer jr.]

For some reason I hear a lot of people with these saws are having to buy new carburetors for them. That may be what you'll need to do.

 

[D&S]

hello all. thanks for all the replies i want to let you know that i found the problems. its kinda funny but the spark plug wire was not on. it was just kinda touching that would explain the breaking up and the intermitten no start then start. i vacuum tested the fuel line and it was good and i check the tank vent and it was fine so on a hunch i suspected a bad fuel filter and i was right. i emptied fuel tank to do test on fuel line and when i put new filter on it started to siphon fuel almost instantly the old filter didn't do that. the hard part inside filter had broken down and was soft. probably thanks to ethano. i fired it up and it seemed to run good. i will tweak the carb a little next week once i get it up in the bucket. i will report back the results.
thanks again everyone.
dan