Having trouble raising the rpm on a Husqvarna 395XP

[Stihlsawshop]

I have a Husqvarna 395XP that has given me a fit. I buy every saw I work on and have overhauled several of this model. This saw has a problem that is new to me. I tore it down and gave it a thorough cleaning. Installed new crank seals, new fuel line and filter, new intake manifold and impulse line. The cylinder kit I installed is a Hy-Way brand Big Bore and I have used several of those. I used a stock base gasket and the saw pressure and vacuum tested perfectly. I overhauled the carburetor with a OEM kit. Put it on and the saw cranked right up. I set the high to about 11,400 and sent it to the park service for break-in. They ran 4 tanks through it. I got it back and went to turn up the rpm and I could not get it above 11,500 rpm. I almost ruined the new setup trying to lean it up. I pulled off the carb and put one off of my saw on it, same result. I have now also had two different coils and flywheel combinations on this saw and its the same. You can't raise the rpm by leaning up the fuel. You can adjust the high to way too lean and it stays the same. Can anyone come up with any suggestions of something I am not thinking about? I have already checked my fuel line and filter for a restriction as well as the tank breather. The saw is reliable as can be but is running a little less rpm on top end than I would like and I dont care to sell it like this. Thanks

 

[shortfuze82]

Check your muffler . Make sure the screen is not plugged . Or that you don’t have that baffle broke off rattling around in there potentially blocking the outlet when the saw is moved around mainly this shows up when the guys lay it clutch cover down for a flush cut. What your describing seems to be different tho . Anything’s possible just take it one step at a time an if that doesn’t work post again we can dive further if we have to do so. With the saw sent out at 11,500 it is pretty rich and with them putting 4 tanks thru it moslikley not staying in the throttle heavy most times it’s possible that screen is restricted. General rule of thumb you should back off the max rpm 500 rpm not much more for breakin on a new or rebuilt saw. 12500 to 12700 is factory spec on these

 

[Stihlsawshop]

I forgot to mention that I had checked the screen on the muffler already but I do need to take it off and check the insides out. Thank you for your quick reply.

 

[shortfuze82]

Pull the muffler first thing tomorrow an let me know you got me curious

 

[Stihlsawshop]

I will do. Thank you

 

[Little Al]

Rev limited coil with a hangover ?

 

[shortfuze82]

95 coils are not limited

 

[mountainlake]

I'd vote for a clogged muff .. Have you tried a new plug. Steve

 

[Andyshine77]

Is the flywheel indexed correctly? If everything these boys mentioned checks out. I wonder what the port timing numbers of that Hy-Way top end look like? Maybe even check for free porting, I've seen that on a couple of the low end cylinders.

 

[pioneerguy600]

Is the flywheel indexed correctly? If everything these boys mentioned checks out. I wonder what the poor timing numbers of that Hy-Way top end look like? Maybe even check for free porting, I've seen that on a couple of the low end cylinders.

That is the direction I would be looking at since most of the rest areas have been looked at or changed out.

 

[Stihlsawshop]

So this is what I found out. I looked the muffler over and it looked fine inside and out. The screen wasn't oiling up at all. I double checked the flywheel and timing and verified it against my own personal saw that is set up the same way and they are the same. I did notice though that with all the trying to lean up the fuel to raise the rpm that my piston is not looking as good as it was so I am just gonna tear the saw down again and start from scratch. There is something simple causing this but I am ready to move on. This saw has frustrated me and I have kicked it aside 3 times already. I am in deficit labor rewards already so just gonna redo it, give to to the park service for four tanks, check it, and get it out the door. Thank you for everyone trying to help me.

 

[grizz55chev]

Giving up on it before finding the problem will haunt you. I say pop a different top end on it and at least eliminate that as the problem.

 

[Stihlsawshop]

Giving up on it before finding the problem will haunt you. I say pop a different top end on it and at least eliminate that as the problem.

That is what I meant by what I said. Sometimes I don't word things right if I am tired. I will carefully inspect the cylinder I take off then put another p/c kit on the saw and get it to running that way. Something has to be wrong. I dont ever give up on the timber saws. The little home owner junk is a different story. Thank you

 

[Chainsaw Jim]

I wouldn't be surprised if the squish is close to .100"

 

[shortfuze82]

I’m glad your one of the few that takes pride in your work most would just leave it go out the door like that . Your perseverance speaks volumes of your character buddy don’t give up until you figure it out an keep us posted every step along the way if it proves to be the byway top end call up where ever you bought it from and read the riot act and don’t give in until you get a replacement or full refund . This world is full of to many moist asses these days that would just let something like this go out knowing it’s not 100 percent

 

[Stihlsawshop]

I’m glad your one of the few that takes pride in your work most would just leave it go out the door like that . Your perseverance speaks volumes of your character buddy don’t give up until you figure it out an keep us posted every step along the way if it proves to be the byway top end call up where ever you bought it from and read the riot act and don’t give in until you get a replacement or full refund . This world is full of to many moist asses these days that would just let something like this go out knowing it’s not 100 percent

I own almost every saw that I work on an for the most part I only sell on Ebay. I take off in new directions and make a day of buying every saw, carcass, or part I can get my hands on and three weeks ago I bought 30 saws from a dual brand dealership, Stihl and Husqvarna. They take saws in on trade. I bought 24 parts saw and six saws in the group that were runners and been repaired by the shop. They cranked up an ran decent, some needed a little something here and there, or so I thought. I watched them work on saws for 3 hours. They had no compression tester or a pressure/vacuum guage set. I asked about compression and the lead mechanic said he could "feel the compression." I should have ignored the runners they had. I didnt give anywhere near what they gave for the trades and still took a screwing. It blows my mind what some would call a repair. Some of the saws had 4 or 5 leaks and I could not beleave the fuel pumps could even operate. Broken crankcases underneath replaced covers. You name it. I am not sending anything out the door that can't go to the woods unless its a parts saw I am selling and every fault I can find will be called on them. I would love to be a dealer for saws but I am not fond of their rules for fixing saws. Then I get in a dealers shop and I laugh at some of the crap I see going on. Thank you for your reply. It meant alot to me.

 

[shortfuze82]

The world needs more guys like you especially in the saw repair business where I believe in this new auto tune and m tronic age the hobbyists know more then the dealers ! I’m dead serious

 

[Stihlsawshop]

The world needs more guys like you especially in the saw repair business where I believe in this new auto tune and m tronic age the hobbyists know more then the dealers ! I’m dead serious

I watched a video on the Stihl 500i today. I didn't know it existed and I did decide I think it will be better than the M-tronic computerized saws. I am looking at a group a timber cutter has tomorrow afternoon that is supposed to have some of those in it. About 8-10 saws. I can't blame Stihl or Husqvarna for the new ways. The EPA is killing of every mechanical engine I have ever loved. From electronic Cummins diesels, to Tier 4 tractor engines, to computerized saws. I just can't see making everything so complicated and disposable. Hell of a way to save the enviroment.

 

[huskihl]

Using any cylinder other than oem throws the max rpm #'s out the door. It's the porting that makes it turn a specified max rpm. 9 times out of 10, am ports are smaller than oem

 

[Stihlsawshop]

I don't get to work with anything but aftermarket cylinders so I have no experience there. I wish I did. I have used this aftermarket setup several times before and they are able spin the saws plenty fast. Something is wrong this time and it will be a few days before I get back to it. The cylinder has a warranty so its all good. I did top handle relics today and will do firewood saws tomorrow and first of the week. Thanks