new guy need help with porting!

[slimm77]

hey everyone, I just joined hoping I can get some help from all you guys! I have been working on saws for years, I have never not been able to get one running, thats not why I am here today, I have be pushing the idea around for years about building a hot saw but have just recently decided to, I have a couple of stihls (038super) and husky 266, but the one I have already started on is a makita 6401 same as dolmar I have already made a custom stainless dual port muffler and changed the jetting also made an advanced timing key, needless to say the saw will easily out cut all my others but I want more and the next step I guess is to either port the piston or cylinder? I need suggestions as well as photos of how to port it, I want to do all of the work myself I do have alot of money to pay out for someone else to do it plus I love messing with it. I have all of the tools I am sure and if not I can get them I am a certified welder so the metal work for the muffler was easy, now the saw sounds like a sand rail, just needs more top end . I hope to hear what you all have to say and again suggestions on other mods welcome!
thanks,
Ben:chainsawguy:

 

[slimm77]

hey everyone, I just joined hoping I can get some help from all you guys! I have been working on saws for years, I have never not been able to get one running, thats not why I am here today, I have be pushing the idea around for years about building a hot saw but have just recently decided to, I have a couple of stihls (038super) and husky 266, but the one I have already started on is a makita 6401 same as dolmar I have already made a custom stainless dual port muffler and changed the jetting also made an advanced timing key, needless to say the saw will easily out cut all my others but I want more and the next step I guess is to either port the piston or cylinder? I need suggestions as well as photos of how to port it, I want to do all of the work myself I do have alot of money to pay out for someone else to do it plus I love messing with it. I have all of the tools I am sure and if not I can get them I am a certified welder so the metal work for the muffler was easy, now the saw sounds like a sand rail, just needs more top end . I hope to hear what you all have to say and again suggestions on other mods welcome!
thanks,
Ben:chainsawguy:

I guess I will figure it out on my own, Have had no replies I guess because I am not modifying my stihl!

 

[Brownpot Deaton]

well...

this isnt the post post area..should have tried regular chainsaw post,,this one isnt checked often...

and a better site for this type of question is ######## dot com...many of those guys build very custom and high powered saws..many of whom are members herw...only difficulty is its not checked as often and has fewer members...

would like to seem some pictures of your saw...maybe post them on regular chainsaw portion here..

 

[Mr.]

What is your specific questions?

Fred

 

[Freakingstang]

start off widening the ports and tighten up the squish. See how you like that and then go from there.

Then bolt on the 7900 topend.

They are not just like the 7900. The 6400/6401 is an open channel transfer port and the 7900/7901 is a quad loop closed transfer.


What do you want the saw to do? Cut like a mofo and last forever, will all the torque in the world to pull a 96" bar? Ain't gonna happen. You need to get a realistic goal of what you want it to do first, then read up on two stroke theories and talk to some knowledgable people. That fred guy (MR) is one of them. He had built a saw or two in his day.


Just because you have the tools to totally hog the cylinder out, doesn't mean that is the best approach. Whatever you do, start conservative. You can always go back and take more material, but it is real hard to add material.


-Freak

 

[Brownpot Deaton]

good advice from freakinstang-as usual...

and fred..is that a 359 cylinder...???how did it run and any problems??

 

[Mr.]

good advice from freakinstang-as usual...

and fred..is that a 359 cylinder...???how did it run and any problems??

Yeah, that's one of the few pics I have here at work. I really need to bring some more pics up here.

That saw ran really strong. All I had was a 20 inch bar for it so I put a 20 inch bar on an 066 and you really couldn't tell any difference with the bar buried.

There is alot of easy power in those things, but alot of 4 cube saws are like that. If you have a four cube class near you............ then you need to leave that 6400 cylinder on it and have some fun. Not too many people have a real strong 4 cube and you might catch someone looking.

Fred

 

[Brownpot Deaton]

There is alot of easy power in those things, but alot of 4 cube saws are like that. If you have a four cube class near you............ then you need to leave that 6400 cylinder on it and have some fun. Not too many people have a real strong 4 cube and you might catch someone looking.

Fred

so if i understand this right, a 6400 cylinder will fight on a 359????scratching head...maybe i read it wrong, but if so that's pretty sweet!

i just modded a 359cylinder and it looks like yours in general with the transfers...that things rpm "snaps" so fast its amazing....only problem we are having now is getting it to idle...may be a crank case leak somehow or a small hole in the carb to cylinder boot....not sure, but it idles perfect cold but after 2 minutes its so bad it can't run anymore...you wouldn't happen to know what might cause this or have any help/advice...the gentlemen helping does stihls so he doesn't have a vac/pressure tester for the case...i guess take it to a dealer, but thats a long drive...

Jordan

 

[OilHead]

hey everyone, I just joined hoping I can get some help from all you guys! I have been working on saws for years, I have never not been able to get one running, thats not why I am here today, I have be pushing the idea around for years about building a hot saw but have just recently decided to, I have a couple of stihls (038super) and husky 266, but the one I have already started on is a makita 6401 same as dolmar I have already made a custom stainless dual port muffler and changed the jetting also made an advanced timing key, needless to say the saw will easily out cut all my others but I want more and the next step I guess is to either port the piston or cylinder? I need suggestions as well as photos of how to port it, I want to do all of the work myself I do have alot of money to pay out for someone else to do it plus I love messing with it. I have all of the tools I am sure and if not I can get them I am a certified welder so the metal work for the muffler was easy, now the saw sounds like a sand rail, just needs more top end . I hope to hear what you all have to say and again suggestions on other mods welcome!
thanks,
Ben:chainsawguy:

- There is another site that will be helpfull with what your trying to do. I'll probably catch some flack for postin it but they arent sellin anything over there. I have personally purchased many products from sponsors here . Anyway here it is in encrypitc version because the site will kick it out. ########-_-_===.Com Keep in mind if you make one slip when performing sergery you will kill the patient.

 

[OilHead]

Ummmm Didnt like that.. -- Race===Saws===.Com

 

[Brownpot Deaton]

ypu..thats the one i mentioned...i really like the build offs they do...soo much to learn from....

 

[Mr.]

so if i understand this right, a 6400 cylinder will fight on a 359????scratching head...maybe i read it wrong, but if so that's pretty sweet!

i just modded a 359cylinder and it looks like yours in general with the transfers...that things rpm "snaps" so fast its amazing....only problem we are having now is getting it to idle...may be a crank case leak somehow or a small hole in the carb to cylinder boot....not sure, but it idles perfect cold but after 2 minutes its so bad it can't run anymore...you wouldn't happen to know what might cause this or have any help/advice...the gentlemen helping does stihls so he doesn't have a vac/pressure tester for the case...i guess take it to a dealer, but thats a long drive...

Jordan

No, on the 6400 cylinder. I was responding to two people in one post.

The carb on that thing is junk IMHO. I had to drill my carb just to get it to richen up. I bet it is an issue with the carb, but you really need to pressure check it first.

Fred

 

[slimm77]

porting

I want some more torque at the top end, I have worked on alot of two strokes and I know pretty much everything I need to know to get them running good in a stock aspect, I know what the ports do but I am unsure of how to cut them to get what I want out of the saw. I know you get different results buy going wide or tall and so on. I have an old cylinder off a remington SL 55 logger I am practicing on now, I plan to put it on a super xl crankcase which I have do before, I will put up some pics and see what you all think, I just went wider on the exhaust nothing major but before I cut up one of my good saws I wanted to practice a bit.
I am running a 28" roller tip and a full chisel(runners cut down) pulls good just needs a little more a$$ in the hard stuff, I have modded the muffler and air intake also bumped the timing, cut out the stock key way on the fly wheel to accept a standard key and the made an advanced key and jetted the carb. I will have pics of this saw as soon as I charge the camera.:help:
Thanks for the replies, keep um comin!

 

[OilHead]

so if i understand this right, a 6400 cylinder will fight on a 359????scratching head...maybe i read it wrong, but if so that's pretty sweet!

i just modded a 359cylinder and it looks like yours in general with the transfers...that things rpm "snaps" so fast its amazing....only problem we are having now is getting it to idle...may be a crank case leak somehow or a small hole in the carb to cylinder boot....not sure, but it idles perfect cold but after 2 minutes its so bad it can't run anymore...you wouldn't happen to know what might cause this or have any help/advice...the gentlemen helping does stihls so he doesn't have a vac/pressure tester for the case...i guess take it to a dealer, but thats a long drive...

Jordan

- I had the same problem with a MS440 after a woods port job & a walkerized dual port muffler in addition to the stihl dual port front cover. Couldnt get the idle low enough to stop the chain. Rechecked the tang setting on the carb was ok. Pressure checked it & replaced one of the seals dealer didnt have the tool for the other side. Only a slight improvement after that. Final set was 13,800 not the 14,200 rpm I was shooting for that along with turning up the idle speed screw . Its good now but know its capable of just a tad more if the the jet was opened up . Richen up the top end it should go away. Hi

 

[joesawer]

I want some more torque at the top end, I have worked on alot of two strokes and I know pretty much everything I need to know to get them running good in a stock aspect, I know what the ports do but I am unsure of how to cut them to get what I want out of the saw. I know you get different results buy going wide or tall and so on. I have an old cylinder off a remington SL 55 logger I am practicing on now, I plan to put it on a super xl crankcase which I have do before, I will put up some pics and see what you all think, I just went wider on the exhaust nothing major but before I cut up one of my good saws I wanted to practice a bit.
I am running a 28" roller tip and a full chisel(runners cut down) pulls good just needs a little more a$$ in the hard stuff, I have modded the muffler and air intake also bumped the timing, cut out the stock key way on the fly wheel to accept a standard key and the made an advanced key and jetted the carb. I will have pics of this saw as soon as I charge the camera.:help:
Thanks for the replies, keep um comin!

You need a degree wheel to check and set your port timing. The port timing is similar to the cam in a four stroke. Moving the port the ports will affect the rpm range that the saw wants to run in.
Here is a good link to degree wheels http://www.arboristsite.com/showthread.php?t=40826&highlight=degree+wheel
Most of the time an offset key to advance the timing is not necessary. The key just locates the fly wheel in the proper stock location. The taper fit is sufficient to hold it. I have a few saws with out a key at all, just a line or two scribed in the fly wheel to reference the timing.
Have fun and good luck with your saws.

 

[weenieroaster]

i just modded a 359cylinder and it looks like yours in general with the transfers...that things rpm "snaps" so fast its amazing....only problem we are having now is getting it to idle...may be a crank case leak somehow or a small hole in the carb to cylinder boot....not sure, but it idles perfect cold but after 2 minutes its so bad it can't run anymore...you wouldn't happen to know what might cause this or have any help/advice...the gentlemen helping does stihls so he doesn't have a vac/pressure tester for the case...i guess take it to a dealer, but thats a long drive...
Jordan[/QUOTE]


Does your 359 have a plastic clip on the intake boot, or a metal one. There is an issue with the plastic ones, they often leak. Husky made amends, and the dealers were changing them out for free at one point. Test for leaks.

 

[timberwolf]

I am running a 28" roller tip and a full chisel(runners cut down) pulls good just needs a little more a$$ in the hard stuff

If you need to file down the rakers on a 28 inch full comp chisel chain, then sounds as if your chain is not right. That is a lot of bar to ask that sized saw to pull, even ported it's still a lot to ask, esp in hard wood.

 

[Brownpot Deaton]

have somebody special woeking on it right now and they just replaced the plastic one with the metal one and it still does it...they believe, and i agree, that either the bearing crank seals have got small leak or the crab boot has a small nick in it...which i believe the socond cuz a forgot to put the boot on the cilender before i attatched the cylinder to case but diidnt feel like redoing the rtv gasket makeri used to replace the gasket material so just took a dremel to the flanges and made them fit...probably the dumbest thing ive done to that saw...amazing what youll do when you have one step between you and you goal...

 

[slimm77]

nothing wrong with my chain just like um to throw sticks instead of chips, and rakers/ runners! you say potato I say tader, same difference.

If you need to file down the rakers on a 28 inch full comp chisel chain, then sounds as if your chain is not right. That is a lot of bar to ask that sized saw to pull, even ported it's still a lot to ask, esp in hard wood.

 

[slabmaster]

Sounds like your rakers are too low for the saw.With a 28" bar you might get away with it on a 395,but your saw is probably too small especually in hardwood.Right call TW. Mark