Starting another new chainsaw project

[Karla]

I am getting ready to start another new chainsaw project and have a couple of questions, I plan to rebuild another Husqvarna Model 545, too funny. My last Model 550 turned out perfect, My project should arrive sometime this week and its an Autotune, the owner says it has a hot start problem but runs good just trouble restarting it when its hot. I don't know If I will need a cylinder until I obviously take it apart and look at the cylinder/ piston, and I'm hoping maybe its just an autotune carburator problem which I can do the diagnostics on, and obviously take it apart. So here is my Question - where can I find a reasonably priced cylinder for a Model 545, like are there any aftermarkets ? or good sources ? Some Husqvarna parts dealers are just too pricey, and won't sell just a new cylinder. Oh, also the owner thinks his hot restart problem might be the ignition coil, I sort of don't think so, but I have spare New autotune carburetors and New ignition coils, so that won't be a problem. Also If anyone thinks of anything else I should check then please let me Know, I will be taking it all apart like I did the Model 550 and try to figure out what caused the problem, and what are the real symptoms. Thanks for any help in advance.

 

[Karla]

Oh, I have been looking for any Husqvarna Service Letters or SILs related to Model 545/ 550 Autotune Hot start problems, So if anyone knows of some documentation please let me Know. I did find one in their Aug. 2016 IPL update for the 550xp, which has you change the fuel line and fuel tank vent line, but you need to buy a new part to do the update. I also can't figure out how that fix would solve the Hot start problem. Anyhow, It looks like there recommendation is to disconnect the vent line from the fuel tank vent, and then plug the other end of the vent line in the carb. compartment, but again really can't see how that will fix anything but its easy enough to give it a try. Lol

 

[barton174]

Hot weather + hot saw, or just hot saw? I think you responded to my 550XP question on husky's forum. I'll let you know how it shakes out, as far as what they replace under warranty and such. I know they'll put the updated top cover with the hole in it, but it's up for debate as to whether they'll put the updated carb on it. I kind of suspect you won't find anything wrong, as far as P&C, if it runs right when it's running. There have been some bearing seal problems, though.

Mike

 

[Karla]

Mike, yes that was me on the Husqvarna Army site, and I would definitely like to know what they tell you, and If there is an improvement when you get the chainsaw back. They may just put a new carburetor on the chainsaw, and let it get returned to you. I always like to find out what caused the symptom, and if I can't find the original problem then I didn't fix anything, so replacing parts is a technique to fix it but you will never know what caused it. Lol. I am hoping my New project due to arrive tomorrow, hooray, hooray will have a good cylinder, piston and piston rings, because for some strange reason they are pricey parts on Model 545's/ ,550's. My hobby is taking the Husqvarna models apart and finding problems, I call it my Forensic Diagnostics'. Lol I have always been able to get them running and my success rate is 100 % so I am pretty impressed with that in fixing them but really finding the "Root Cause" is what I am looking for in my forensic diagnostics. I have answered over 850 questions for Husqvarna's Answer Army, and again its just a hobby. I am Not a Representative or Dealer, or Repair Service, just an experimental chainsaw person. Husqvarna last year even awarded me a brand new Husqvarna 545 for helping to answer their questions, So I know that they know I know something. Lol too !
Bye and please keep in touch at either website, Thanks.

 

[Karla]

Mike, also thanks for the Info on seals, I always do all the tests on the chainsaw, including Mighty Vac both pressure and vacuum on cylinders, etc. I haven't really seen too many seal problemson these chainsaws, I have on other brands but If I'm rebuilding the chainsaw replacing the piston/cylinder or crank, I always put new gaskets and seals on the engines. Oh, I also test them before and after, since again I am looking for the real problem child. Lol.

 

[Karla]

Mike, In answer to you question about "Hot saw" , I never thought about those words when I wrote them, but chuckling a little, and No I bought the saw from the Original Owner who said the chainsaw was hard to start when it was Hot. Lol

It arrived today, hooray, hoorray and the carburetor compartment was filthy I almost couldn't find the carburetor, and definitely couldn't find the autotune wiring and connector. I used some compressed air and cleaned the dust and dirt off. Also ran the diagnostics and got some error codes, (17/23 /17/23 /554/56 /554/56) so error code 17 says siezed upper piston. I pulled the muffler, and hooray No scoring that I could see, However alot of varnishing or baked on oil on the piston on each side of the exhaust port area on the piston.

I need a quick break for dinner and will continue my as found conditions in a little while, Any thought yet Maybe from one of those Autotune diagnostic guys ?

 

[Karla]

Here are the diagnostics:

 

[Karla]

Oh, I did test the carburetor, and all of the diagnostic tests passed. I have the engine soaking overnight with some LMT cleaner on the piston inside the cylinder, I have not taken the piston/cylinder apart yet. The piston ring is not stuck, and do not see any carbon in the piston groove, with a little added lubricant in the engine I pulled the engine over and it seems like it has good compression, and the piston moves freely, so there is No seize, However error code 17, stated that there was a seize, not sure how the software figures that one out, but very interresting, and I am still learning. I am so happy with my broken 545 chainsaw, Lol. I really have some forensic diagnostics to do. From some reading and looking at piston pictures, the piston varnish and baked engine oil, from what I have determined say that it is caused by stale fuel ? Again the Jury is still out, so any comments or suggestions would be appreciated. If the piston doesn't cleanup overnight, I may just take it apart and replace just the piston and ring. Also tested the ignition module, and it has a very strong spark, so I'm happy with that too. Tomorrow, I will do some more cleaning, and checking all of the other parts (ie clutch, oiler, etc.), also perform a compression test, and pressure/ vacuum test on the cylinder too. Then depending on what else I take apart and clean, probably start to put it back together. Oh, I also too a quick peek at the fuel filter, air filter, and spark arrestor which all look pretty clean. The spark plug was black with carbon, and some carbon maybe .005" on the inside of the exhaust port but not really bad, but I will wipe the carbon clean, and put a new spark plug in to the chainsaw. I will probably also remove the carburetor, so I can give it a thorough cleaning, and check the condition of the fuel lines and tank vent.

Anyone can think of anything else I should clean and check ? Again, I would like to find out why or If this chain saw really had a Hot start problem.

 

[Karla]

Oh, here is a picture of the Model 545 autotune carb. compartment, Can you find the carburetor ?

 

[barton174]

Wait, if you're not a dealer, how do you have the autotune software? I heard you could get the cable and the adapter, but couldn't get the software unless you were a dealer?

Mike

 

[Karla]

Mike, Yes that is true. But I managed to do a lot of networking, and got some help. I am Not able to get carburetor updates or may not be able to read Newer Chainsaw Carbs because you would need to be a Dealer and get that Information directly from the Manufacturer. But there are some Dealers that will sell the Diagnostic tool reasonable, but I had to work at that a little too, and some Dealers won't even sell the Diagnostic box and cables even though they are listed in their catalog, and the kit # is listed in the IPL's. . I have been on my quest for over a year now, and I am also still learning. But I definitely know alot more now, but again still learning.

 

[barton174]

Yeah, I knew you could get the cable and stuff, but I heard that all the diagnostic software for the cable was dealer-only, had to have an online login to even open it, or something.

Mike

 

[Karla]

The overnight soak, did not clean up the piston to my liking, so I guess that I will be taking the cylinder apart for a more thorough engine cleaning and Inspection. I also did a compression test (cold) on the engine and only got 110 psi after about 6 pulls with WOT, so a little disappointed there, but Maybe I need a New piston ring. However after only 98 hours of use on a three year old chainsaw I wouldn't think the piston ring would be going ??? Anyone have thoughts on how many hours one should get on a piston ring ? I guess its a difficult question because we don't know if it was 98 hours of use with a good sharp chain and lite loads on the engine, or 98 hours of abuse with a dull chain, and lots of loading and heat being created. The clutch doesn't show any signs of overheating, and some wear on the drive sprocket, which I will probably replace, along with the bearing and a New bar and chain. Oh, I did clean-up and dissassemble the Autotune carburetor, a little bit of dirt in the screen strainer, and a liitle bit of stuff on the metering needle, but overall the carburetor looks good after 3 years of use, also checked the metering lever height but no problem there either. Anyhow its all nice and clean inside and out, I also Re-tested the carburetor again and everything checks out Ok. So I don't believe the initial problem was a carburetor problem, also got a chance to look into the intake side of the cylinder which also looks real good, so the only problem I see so far is some varnishing on the side wall of the piston.

Cleaned up Autotune carburetor, and also tested both electrical connectors and plugs:

 

[Karla]

I have read some more about piston damage with varnishing on outside of piston, and besides the stale fuel pictures which say its baked on fuel oil. Another picture of a similar looking piston says it piston ring "blow by", so now I'm really not sure except it sounds like I really need to take the engine apart, and remove the piston, and inspect everything, and clean everything up. Anyone have any thoughts or have seen this condition ? I have a new piston and piston ring, piston pin and circ clips on order, and should be here today or tomorrow. The price seemed reasonable enough, $24.95 and I will just replace everything. Maybe clean up the older and take some measurements, and save for an emergency spare. Lol.

 

[MountainHigh]

interesting thread .... I'm learning something from your questions/procedures and admire your initiative.
I hope to tear down my 346 when I get some spare time and it will be my first rebuild.

 

[Karla]

MountainHigh, Just my two cents: " Definitely do it, If it is needed". Its alot of fun and definitely addictive, learning and knowledge is on going. I almost like rebuilding engines more than cutting wood, but falling and cutting up a tree is still the most fun. As you do your rebuild just some suggestions, take notes of what your doing, like type them into the computer, take lots of pictures during dissassembly and put them in the computer too, Do lots of research before taking the chainsaw apart ie. Get Illustrated Parts Lists (IPL's) for your chainsaw, Get Owners Manual (OM) info if you don't have it, A workshop Repair manual if available for your model, and Do your Homework before hand.

Most importantly, On your first re-build take your time - "Do Not Rush", and enjoy the rebuild thinking about the steps you have completed and the steps that you still need to perform. Take measurements where you can ie piston sizes, cylinder dimensions, hardware sizes ie. screw dimensions, etc. Again just alot of fun, I have done about a dozen or more rebuilds in the last year of different manufacturers, and I am still learning, and asking questions. Also Don't forget to Please Ask Questions, If you can't find the answer, or just want another opinion, or are just Not really sure. Good luck, and have fun, and I will always be glad to help If I can, or give my opinion. Lol.

 

[Karla]

Mountainhigh, Also Thank you for the compliment on my rebuild, I believe my new piston and ring kit will be here today, Hooray. So I will take some measurements, measuring piston diameter, piston ring side clearance, and piston ring end gap. Then when I dissassemble my piston and cylinder which may be tomorrow, I will retake the same measurements with the old parts and compare the results, It may tell me If I had a severely warn piston ring by comparing the new to the old. Its just a hobby for me, and definitely not a business, I spend way too much time on my re-builds. Lol.

 

[MountainHigh]

fantastic feedback ... I can see why Husky gave you a 545!

I've been burning and cutting wood for many years and have always wanted to do more than just hand off saws when something beyond chains, obvious filters, plugs etc goes wrong. When I get the time to start, I'll be hounding you with questions no doubt ;-)

Hoping others will chime in on this thread to assist with your questions.

Thanks for your generosity.

If you ever do a video on one of your re-builds, please let me know.

 

[Karla]

MountainHigh, Yes I have tried to do a video, but I had trouble getting it to view more than a few seconds, it was a few minutes when I took the video. I am Not very knowledgeable of the on-line video stuff.

In the search box above, type in "550 challenge", that was my last re-build on a Model 550, and very similar to the one I am re-building now Model 545. There is a very short video after I got it running again, but Not happy with how the video didn't run long enough. So before I do any Instructional Video's, I need more knowledge of how to make a video, Lol. and another hobby ("How to make video's").

Oh, Just one more thought for you, After you have done a rebuild, try doing another. After you have done several, you will find it gets very easy. I pick up a lot of mine up at yard sales, recycle centers (yes-there are people who throw them in the dump), and occassionally E-bay If its something special or similar to one I have and just want extra parts, Lol. But even the part ones, I always get running so I have to be careful how many I buy. LOL too.

 

[MountainHigh]

So before I do any Instructional Video's, I need more knowledge of how to make a video, Lol. and another hobby ("How to make video's").

A very basic but FREE Video Editor here to use on your PC :
https://support.microsoft.com/en-ca/help/14220/windows-movie-maker-download

(some smart phones and some programs make this whole process even simpler, but that's another story)

After shooting the video, transferring it to your PC, and then editing (if needed), and then outputting your final video from your video editor onto your computers hard drive as an .MP4 file or in the case of Movie Maker, an .avi file and maybe other options that I can't remember just now, then do the following:

1) Start an account with vimeo.com or youtube.com

2) Login and upload your video to your account (self explanatory once you're in there).

3) Copy and Paste the URL that links to your video into any conversation you wish here.

The more videos you do the easier it will become.



I sometimes go days without logging in here but if you wish, message me and I will answer any questions on video editing I can.