Infrared testing of 2 cycle temps?

[Arkie]

What would you expect to be a normal block engine temp for a 2 chainsaw engine when testing with a Infrared thermometer?
And what would be a too high block temp range probably checking the jug area temp?

Anyone ever try checking or monitoring the block temp of a 2 cycle or chainsaw to detect when temp is getting out of normal range due to lean carb adjustments or other overheating issues???
Reason I'm asking is I have a chainsaw engine that seized during operation and when it rested for few hours it freed up and suspect lean running due to carb adjustment. (oil mix and all else was ok)
Saw was being operated into max bar cuts and heavy loads on the engine and engine running real good until the engine seized in a cut. Piston and cylinder still look ok and compression checks same as before seizure. (I had tested the compression few weeks before when testing a new Actron gauge is why I know it's still the same compression)
Saw is now running strong as before and I want to monitor it's block temp with the infrared thermometer when retesting
in a heavy load cut to watch for overheating condition again and adjust the H jet to reduce heat if possible.

The saw is a Stihl 028AV!

[KE4AVB]

I suspect either a crankcase seal leaking under load causing a lean out condition,intake air leak or the cylinder air flow is blocked. You could be also exceeding the saw's max 120000 operating rpm which is limited by running a richer mixture.

I would suggest contacting the Arboristsite.com chainsaw group as they got a lot experience when it comes to these chainsaws. They probably will be able to give some good numbers for cylinder temps as there are a lot modifiers there.

[Arkie]

I suspect either a crankcase seal leaking under load causing a lean out condition,intake air leak or the cylinder air flow is blocked. You could be also exceeding the saw's max 120000 operating rpm which is limited by running a richer mixture.

I would suggest contacting the Arboristsite.com chainsaw group as they got a lot experience when it comes to these chainsaws. They probably will be able to give some good numbers for cylinder temps as there are a lot modifiers there.

I suspect you are correct about lean and overtemp. I was trying to monitor temp so as to prevent another meltdown.
I tried the arborist site and they suggested same as you about lean conditions! No reply about a block temperature using a infrared thermometer. I would think that using the instantaneous read infrared temp would be a good indicator instead of just testing until meltdown or after the fact and guessing it might be ok? I'll try the arborist site again. Their site replies to a post does not go to the top of a thread, a thread just keep getting further down the list by the date and new viewers do not get to see what's really active about replies, whereas this site the new replies goes to the top of the list so as viewers can see what's really active.,

I was trying to get a ball park figure of a temp range that would indicate that any 2 cycle is getting out of a normal block temp range.

Here is a link at the arborist site that I just posted if anyone wants to see if any pro's reply!
http://www.arboristsite.com/community/t ... er.290447/

[bgsengine]

Block temp checks are simply too dangerous a procedure to do - If the saw is operating at the correct RPM range and with correct fuel mixture, it should not at all overheat if you maintain cooling cleanliness - Just run it with an *accurate* tach on it... Too lean of a mixture will cause RPM issues, as will just about anything else that also causes overheating. Blocked exhaust will also cause overheating, as will wrong spark plug, poor cooling, improper fuel mix or grade - but just about all of them will show up in an RPM problem with a carb that is initially adjusted to spec and then adjusted within limiter range. RPM checks and carb adjustments should only be done on a completely warmed up unit at operating temperature and RPM set according to manufacturer's procedures. Nowadays EVERY 2-stroke manufacturer will have precise specifications as to exactly how to do a carburetor adjustment to maintain EPA compliance - deviation from those results in a "Your Mileage May Vary" disclaimer. That is another major factor in our reasoning that we no longer offer repair services on brands we do not carry or have access to current manufacturer service information - failure to follow manufacturer procedure on carb adjustment of an EPA Compliant 2-stroke puts you at risk (however infinitesimally small) of running afoul of EPA regulations and the associated fines that go along with it.

We have a non contact infrared thermometer (Raytek) we do use in some diagnostic work - but primarily only for 4-stroke engines - 2-strokes by design generally do not overheat when they are adjusted and running properly to manufacturer specifications. One other thought that comes to mind - but again that is covered by cooling - Make sure your saw is operating with (or without as the case may be) the Winterization Plug for the temperature it is being used in . Typically it is a movable plug in the cooling shroud between air box and cylinder that allows heated air from cylinder to be pulled in to the air box - Running a saw with that plug missing or not in place in warmer temperatures will lead to overheating.

[Arkie]

I took 3 chainsaw saws to the wood pile and tested block temps at the piston jugs.

Idling after warmed up average 200 degrees at the jug fins.

In a full bar hard load cut 2 saws averaged 340-380 degrees with engine running loaded down. (the mufflers would get too around 450)


The Stihl 028AV saw in question owners manual indicated the initial setting on the jet as 1 1/4 out and to not go in any more than 1 turn in on the H. I checked the H jet before starting the test and the temp would rise very rapidly on the jug and was still going fast at 380 when I removed the saw from the cut and let it start cooling. I then adjusted the H jet out another 1/2 turn or 1 3/4 total expecting the saw to really gurgle and 4 cycle but only slight gurgle when throttled and would load up good in the cut and when loaded again full bar cut the temp stabilized around 340-360 max.
Test seemed to indicate saw was running really lean at manufacturers suggested initial setting going by the heat building fast and the infrared temp indicating it was headed towards another meltdown even thou the rpms were not being exceeded.
I do not have a chainsaw tachometer and don't know if a tach would have indicated a NO LOAD RPM as out of range.

This test might be similar too the biologist that was testing how far a grasshopper could jump as he removed his hind legs one at a time. His final note was: the grasshopper when both hind legs are removed he apparently becomes hard hearing and will not follow commands!

What brand and make of tachometer is good for chainsaws and not made in China? (without spending a arm and a leg)

[bgsengine]

Test seemed to indicate saw was running really lean at manufacturers suggested initial setting going by the heat building fast and the infrared temp indicating it was headed towards another meltdown even thou the rpms were not being exceeded.
I do not have a chainsaw tachometer and don't know if a tach would have indicated a NO LOAD RPM as out of range.

So how do you know the RPMS were not being exceeded? It is not possible to adjust "by ear" any more on an EPA complaint saw can you really detect a difference of 500-1000 RPM in speed when they are turning twelve grand? I doubt it.. unless you're a Beethoven or Bach..

This test might be similar too the biologist that was testing how far a grasshopper could jump as he removed his hind legs one at a time. His final note was: the grasshopper when both hind legs are removed he apparently becomes hard hearing and will not follow commands!

What brand and make of tachometer is good for chainsaws and not made in China? (without spending a arm and a leg)

Oppama PET-304 from Echo is superb with very fast update times and it is no longer $100+ they can be had for around $65-$75 (Echo part number G310000050 ) I think we still have one listed on ebay yet and probably have more coming this week.

So it kind of depends on your definition of "arm and a leg" - for some people with 3-4 $600-$1000.00 chainsaws, a hundred bucks is a worthwhile investment in maintenance tools.

[KE4AVB]

I use the Tiny Tach here with food results. Only had a few times to act up but that when I using on Rev limited saws and as BGS said I can't tell the difference between 13K and 12K without it.

The service manual indicates the initial H setting is 1-1/4 turns same as the L setting and should not leaned below that .without a tach. I usually end up around 1-1/2 to 2 turns most times here when taching most of the Stihls that I work on. I like to set them slightly lower than the max rpm just to offset different fuel blends.

I had a customer back in the summer that tune his Husky 141LE so lean by maxing the rpms that it literately melted the carburetor adapter.

[Arkie]

Whats your handle (store or seller name) on flea bay for a Oppama PET-304 from echo?

see sellers

Beethoven inquring!

disregard: Found it on flea bay!

[bgsengine]

Whats your handle (store or seller name) on flea bay for a Oppama PET-304 from echo?

see sellers

Beethoven inquring!

disregard: Found it on flea bay!

trukfixer1

A little unusual but it's the one I always had since I joined ebay way back in double-aught and was in the heavy duty truck repair business I didnt see any reason really to change my ID every time I go to do something else..

[38racing]

how does a pet 304 compare to pet 1000 . I see now from my supplier the 304 is 1/2 the price of the 1000 which I have been tempted to order.