390xp Highspeed problem

[CoastRangeCutter]

so i have a 390xp, with an unlimited coil and it also uses a walbro wj-118 carb which doesnt have any stops for the carb adjustments. why cant i run my rpms over 13800? my High speed adjustment is all the way in, what am i missing?

 

[lone wolf]

so i have a 390xp, with an unlimited coil and it also uses a walbro wj-118 carb which doesnt have any stops for the carb adjustments. why cant i run my rpms over 13800? my High speed adjustment is all the way in, what am i missing?

The low might affect it believe it or not.

 

[CoastRangeCutter]

The low might affect it believe it or not.

i re adjusted it a few times. do i need to lean it out more?

 

[lone wolf]

i re adjusted it a few times. do i need to lean it out more?

What max rpm are you looking to get for that Husky? 13800 sounds high enough dont it? I thought they tuned at 13000.

 

[lone wolf]

1. Saw Carb Tuning - Welcome To Madsen's Online
   www.madsens1.com/saw_carb_tune.htm
   HUSQVARNA 272, 372 - 13,500 RPM ; HUSQVARNA 288, 385, 390, 394, 395 - 13,000 RPM ; ... Do not attempt to set at maximum RPM levels without a tachometer.
   

 

[CoastRangeCutter]

just went out and messed with the adjustment, i screwed it in till it died ,then back out till it loaded up, then went back to the middle and a touch leaner. then hit the rpms and its the same. i use a tach, for sure, i guess ill run it for while and see how it goes.

 

[lone wolf]

just went out and messed with the adjustment, i screwed it in till it died ,then back out till it loaded up, then went back to the middle and a touch leaner. then hit the rpms and its the same. i use a tach, for sure, i guess ill run it for while and see how it goes.

Dont keep leaning it out.

 

[middleagemutant]

Coil is probably rev limited.

 

[Andyshine77]

What color is the coil?

Sent from my LG-H871 using Tapatalk

 

[CoastRangeCutter]

thanks for the info, ill send an email out and see if they sent me the wrong one

 

[CoastRangeCutter]

What color is the coil?

Sent from my LG-H871 using Tapatalk

the coil is black. i ordered it from wolf creek saw shop, it said it was unlimited. i believe its a NWP product

 

[Andyshine77]

That coil should be unlimited than, but in my experience these aftermarket coils are hit and miss with quality. That said 13,800 is probably all a new stock 390 will want to spin.

Sent from my LG-H871 using Tapatalk

 

[Big_Wood]

i wouldn't be running a stocker at that RPM. did you verify it's a 118 or did you look it up on the internet? 390's have 116's here in Canada and do have limiters. i don't see you somehow getting one without limiters in north america. regardless, i wouldn't run a stock 390 higher then 13.5k.

 

[CoastRangeCutter]

i wouldn't be running a stocker at that RPM. did you verify it's a 118 or did you look it up on the internet? 390's have 116's here in Canada and do have limiters. i don't see you somehow getting one without limiters in north america. regardless, i wouldn't run a stock 390 higher then 13.5k.

its a 118, and doesnt have limiter, its had a simple port and polish, ported muffler and no gasket, just simple mods nothing outrageous.

 

[Trent Curtis]

Why are you so obsessed with more RPM’s?

Have you checked your tune in the wood? I doubt that saw is 4 stroking out of the cut.

I do really want a 390..... so maybe you should send me yours before you kill it

 

[Andyshine77]

its a 118, and doesnt have limiter, its had a simple port and polish, ported muffler and no gasket, just simple mods nothing outrageous.

Stock 390's will normally be a bit rich at 13,500 but every saw is different. A well ported 390 will want to spin way way past 13,500. Unlimited aftermarket coils are plentiful, and a few unlimited oem coils are still floating around.

Sounds like you're saw is probably best set to around 13,500 unless something else is going on. Is the saw four stroking at 13,500?

And I agree, focusing on rpm and only rpm is never wise.

 

[blsnelling]

just went out and messed with the adjustment, i screwed it in till it died ,then back out till it loaded up, then went back to the middle and a touch leaner. then hit the rpms and its the same. i use a tach, for sure, i guess ill run it for while and see how it goes.

That is not how you tune a saw.

https://www.arboristsite.com/community/threads/chainsaw-tuning-101.250802/

 

[pferdfiler]

I keep my 385-390 @12.800 on the tach n never a problem in 10 years

 

[lone wolf]

I keep my 385-390 @12.800 on the tach n never a problem in 10 years

Thats where my 288 was set forever.

 

[Big_Wood]

Stock 390's will normally be a bit rich at 13,500 but every saw is different. A well ported 390 will want to spin way way past 13,500. Unlimited aftermarket coils are plentiful, and a few unlimited oem coils are still floating around.

Sounds like you're saw is probably best set to around 13,500 unless something else is going on. Is the saw four stroking at 13,500?

And I agree, focusing on rpm and only rpm is never wise.

where did you ever see a stock 390 that 4 stroked at 13.5? lol was the one you had the only one you had experience with? 13.5 is what i tune stock 390's at and none of them 4 stroke warm. ya hear them buzz a little bit cold lol to run one at 13.8 is about the max healthy tune you will get away with without any upper transfer work and even then you need your other work done right. most guys doing there first port job won't know where to go to make them do those RPM happily and end up just making a stronger saw that doesn't do anymore RPM's then stock which is fine. if you port them a certain way the bottom ends run alot wetter so they are more up the the task of managing the higher RPM.

I keep my 385-390 @12.800 on the tach n never a problem in 10 years

now this saw is rich lol