jonsered 621 wow what a freak show this one is need needle locations which ones go where

[sledhead34]

fuel line fixed carb kit and still zero carb adjust is work what is the setting 1 turn out ?? on both screws saw will fire ,,but screams and dies can't get it to settle massive air leak some where it seems

 

[cbfarmall]

Since you kitted the carb, did you use the diamond shaped gasket for mounting the carb? If yes, that is your leak. Proper gasket is larger and covers the elongated impulse passage.

 

[sledhead34]

Since you kitted the carb, did you use the diamond shaped gasket for mounting the carb? If yes, that is your leak. Proper gasket is larger and covers the elongated impulse passage.

used the cut one i made same as factory but i suspect thicker and not sure if they work as good ,but air leaks are suspect around the ball valve tank area everyone i get are rusted garbage
ball valve is all locked up the other deal is needles for the carb i need to know what the right ones look like and where do they go the needle look different then my 52 but i get nothing adjusting them the saw just screams even at 1/.2 open

 

[Cantdog]

Check your cyl base gasket....probably blown out. If you suspect carb problems try swapping the carb from the 52....same exact carb 49 SP, 52/52E/521 and 621.

 

[sledhead34]

Check your cyl base gasket....probably blown out. If you suspect carb problems try swapping the carb from the 52....same exact carb 49 SP, 52/52E/521 and 621.

YEAH figure out the carb should be ok but was thinking base gasket for sure ,next question can you run moto seal or do you need a gasket for sure

 

[Cantdog]

YEAH figure out the carb should be ok but was thinking base gasket for sure ,next question can you run moto seal or do you need a gasket for sure

I wouldn't run any sealer just a dry gasket. To easy to plug up the impulse hole.

 

[sledhead34]

I wouldn't run any sealer just a dry gasket. To easy to plug up the impulse hole.

ok about that impulse hole do guys find try and use the thinnest gasket material is best for that or does it matter ??

 

[Cantdog]

ok about that impulse hole do guys find try and use the thinnest gasket material is best for that or does it matter?

Yes thin is better.....OEM is 0.012 before being compressed.....about 0.007 compressed

 

[sledhead34]

Yes thin is better.....OEM is 0.012 before being compressed.....about 0.007 compressed

ok yeah that`s what i figured ,this could cause some major issues that i can see ,ill have to see what i can find for thin material

 

[Binthewoods]

ok yeah that`s what i figured ,this could cause some major issues that i can see ,ill have to see what i can find for thin material

Don’t worry too much about it, a paper grocery bag will work.

 

[sledhead34]

PRETTY SURE ITS CRANK SEALS IS THE PROBLEM ,AMOUNGST A FEW OTHER THINGS ,,this old 621 is being very finicky

 

[Cantdog]

Perhaps... but I would make certain all the carb gaskets and the cyl base gaskets are in good working order and not leaking before doing the seals. The best way to isolate any of these problems is to do a pressure/vac test but if you don't have equipment or patience to perform this then start by eliminating with the easiest stuff first working the towards the most difficult....that being the crank seals. Personally I always do the seals when I go through any of these old saws....whether they need doing or not...just cheap insurance but is a lot of work involving a special puller for the clutch spyder and a similar but different special puller for the flywheel and you also have to make certain you don't lose your factory ign timing as the entire ign system has the be removed because the seal is behind it. When we have an unknown problem we humans always gravitate towards the most complex of cures when oft times it may be something simple that has been overlooked. That is why I suggest eliminating the easiest problem points first.

 

[sledhead34]

Perhaps... but I would make certain all the carb gaskets and the cyl base gaskets are in good working order and not leaking before doing the seals. The best way to isolate any of these problems is to do a pressure/vac test but if you don't have equipment or patience to perform this then start by eliminating with the easiest stuff first working the towards the most difficult....that being the crank seals. Personally I always do the seals when I go through any of these old saws....whether they need doing or not...just cheap insurance but is a lot of work involving a special puller for the clutch spyder and a similar but different special puller for the flywheel and you also have to make certain you don't lose your factory ign timing as the entire ign system has the be removed because the seal is behind it. When we have an unknown problem we humans always gravitate towards the most complex of cures when oft times it may be something simple that has been overlooked. That is why I suggest eliminating the easiest problem points first.

i use a common puller with long bolts for clutch side and short bolts for recoil its easy mark all ignition timing close detail there ,i can see put the spyder will be a bitch though ,did base gasket and all carb gaskets and zero help so far ,ill get a pressure tester soon but seals are easy insurance on these saws too me ,this one was a run away no control of speed massive air leak checked clutch side looks super dry but its getting a seal recoil side will be next