NO, one piece of solder straight across from the exhaust port to the cylinder wall on the intake side.
Issues after work-over on Makita 6401
- Thread starter NPKenny
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NO, one piece of solder straight across from the exhaust port to the cylinder wall on the intake side.
RiverRat2
Serio Tree Freak
How are you putting the solder in????? tell me your not sticking it in through the exhaust port!!!
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RED-85-Z51
Addicted to ArboristSite
:jawdrop: :jawdrop: :jawdrop: :jawdrop: :jawdrop:
huskydave
Addicted to ArboristSite
I hate to say it but you need to take it apart again 135psi is very low You should have 150psi+. How did the cyl look when you took it apart? I always install new rings when I take a cyl off. You only need a small piece of solder dropped through your plughole to check squish and just tilt the saw to the front to get it close to the cylwall. Then use another one to check the back and tilt it backwards to get it close to the backside. I don't know if you need a piston or not but you should install some new rings. get some batteries and take some pics and we will walk you through it.
10-4.
Yes, I checked the final squish measurement through the exhaust port. Preliminary measurements were checked by crossing two long pieces of solder across the top of the piston as I have seen pictures of on this site.
Man am I glad I have made of these errors on the practice saw. I would be feeling really, really disappointed if I had done this to the 7900 or the 660. I will count my blessings at this point.
Thanks for all of the help.
I think I have found the carb problem.
This is where the carb leaks. Is this repairable or is this part of the carb casing? I could not easily pry this part up so I didn't punch or pull on it.
This is where the carb leaks. Is this repairable or is this part of the carb casing? I could not easily pry this part up so I didn't punch or pull on it.
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joesawer
Addicted to ArboristSite
Your piston is your valves in a two stroke. If it is worn and rocking it can leak enough around the intake to cause problems. For the cost of a piston I always put in a new one if I change the ring/rings. A lot of old tired saws will really wake up and run with a new piston and ring.
With removing the gasket, adding a gasket, porting your cylinder and radiusing your piston there is no way to have any idea of what your timing is without measuring it with a degree wheel. Your timing is probably way off ideal.
With removing the gasket, adding a gasket, porting your cylinder and radiusing your piston there is no way to have any idea of what your timing is without measuring it with a degree wheel. Your timing is probably way off ideal.
This is making some sense. It looks like I will be studying a 2-stroke degree wheel too. This saw is a very large chainsaw lesson in one course.
Kenny- If you get bogged down and want to return the saw to stock for your back-up, I have a mint 6401 cylinder you can have for the cost of shipping. That way you can take your time while going to two-cycle school.
You should be able to use a sharp punch and put a hole in that cover and pry it out somewhat easily. It shouldn't be leaking. You may have to get a carb kit and use a new cover and seal it with loctite or high tack.
NPKenny said:
You should be able to use a sharp punch and put a hole in that cover and pry it out somewhat easily. It shouldn't be leaking. You may have to get a carb kit and use a new cover and seal it with loctite or high tack.
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PM sent.
romeo
Addicted to ArboristSite
This is where the carb leaks. Is this repairable or is this part of the carb casing? I could not easily pry this part up so I didn't punch or pull on it.
A little bead of finger nail polish around the seem will fix that right up. Don't get any in the jets.
Bueno!! Sounds like a trick of the trade. Thank you.
romeo
Addicted to ArboristSite
I forgot to tell you, don't let your wife/gf know that you borrowed it. It really Pi$$e$ them off for some reason.
When used all of her polish remover to clean a shotgun, I definately realized I should have been more sneaky. Good reminder.
Update
I finally came to some sense and decided to intall the new cylinder and pison on this saw, the 7900 set-up that I had ordered. I set the squish to .023 via an aluminum .010 gasket I made.
After buttoning up the cylinder, I pulled a compression test at 125psi after ~8 pulls. What the heck am I doing wrong this time???
I have not run fired the saw (I haven't even put the carb back on). Will the compression come up significantly to get the saw in the 170psi range after the ring seats?
Again, thanks to all of the good counsel in the previous posts.
ps.. The carb sealed up perfectly with the nail polish and is awaiting a test fire.
I finally came to some sense and decided to intall the new cylinder and pison on this saw, the 7900 set-up that I had ordered. I set the squish to .023 via an aluminum .010 gasket I made.
After buttoning up the cylinder, I pulled a compression test at 125psi after ~8 pulls. What the heck am I doing wrong this time???
I have not run fired the saw (I haven't even put the carb back on). Will the compression come up significantly to get the saw in the 170psi range after the ring seats?
Again, thanks to all of the good counsel in the previous posts.
ps.. The carb sealed up perfectly with the nail polish and is awaiting a test fire.
huskydave
Addicted to ArboristSite
The compression will go up about 9-10psi after breakin. If you have a new piston and cyl you should have more compression unless your compression tester calved. How hard is it to pull? You should put a little 10w30 in the cyl before starting it.
Pull felt tighter than my 361. Yes, the piston and cylinder are brand new and the ring fit very well. I didn't notice any leaks at the decomp valve or where the tester threads in.
huskydave
Addicted to ArboristSite
If it feels like it has good compression your tester may be messed up. If you have all new topend you should be good. I have seen bad compression release valves before. They get stuck on sometimes or full of carbon and stick. I am glad to hear things are lookin up for ya.
PES+
Addicted to ArboristSite
Did you check the ring end gap?
Always check the end gap of new rings as too little gap will not self correct with running and it will not allow the ring to seal.
Always check the end gap of new rings as too little gap will not self correct with running and it will not allow the ring to seal.
What are proper specs on new ring gap? I have seen you post about ring gap before, but it never crossed my mind. Thanks.
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