346 OE intermittent bog, won't reach 13k RPM, Revisited FIXED!!!

[andyshine77]

Drill the vent out and put on of these in it. Then you'll know it's working properly.

These work well, I always keep a few around.

 

[Termitebuffet]

What does the plug look like ?

Sawhawgz, ruining the internet since 2012...

 

[decableguy2000]

What does the plug look like ?

Black somewhat fouled would explain no 13k, but carburetor works fine on the other saw.

Fixed my leaky plug adapter and retested, pressure held over 5 min, vacuum dropped 1.5 in in 5 min period. Still thinking it fuel path related, going to go through carb #3 tomorrow, reassemble, and scratch my head some more.

Compression seems a little low 140ish but new ring hasn't seated yet.

 

[Termitebuffet]

Black somewhat fouled would explain no 13k, but carburetor works fine on the other saw.

Fixed my leaky plug adapter and retested, pressure held over 5 min, vacuum dropped 1.5 in in 5 min period. Still thinking it fuel path related, going to go through carb #3 tomorrow, reassemble, and scratch my head some more.

Compression seems a little low 140ish but new ring hasn't seated yet.

Have you tried another plug...

Sawhawgz, ruining the internet since 2012...

 

[Termitebuffet]

Let's math ....
You tried a new carb ...no change
You tried a new coil ....no change
New fuel line and filter no change ...
It appears to be flooding , by plug read ...try another plug to humor me...

Sawhawgz, ruining the internet since 2012...

 

[decableguy2000]

Plug changed, NGKs

 

[andyshine77]

140psi is typical for a 346, so no problem there.

 

[Termitebuffet]

It's gonna be something weird , like the handle was too tight , or the starter rope had one to many wraps on it....

Sawhawgz, ruining the internet since 2012...

 

[sunfish]

140psi is typical for a 346, so no problem there.

140 psi isn't typical for a 346. Every one Ive had (8 or 9) were around 160 psi stock.

 

[beaglebriar]

140 psi isn't typical for a 346. Every one Ive had (8 or 9) were around 160 psi stock.

Agreed.

 

[sunfish]

I've had a couple carbs act this way. I just put on a New carb, a 357xp carb,
Walbro 191, 198, 199. Always runs mo better!

 

[andyshine77]

140 psi isn't typical for a 346. Every one Ive had (8 or 9) were around 160 psi stock.

I have had quite a few cross my bench, some were 353's some were 346's all of them had between 135psi and 150psi. Yes 140 is typical, remember the compression testers are not all equal, the Snap on gauge I have reads 10 to 15psi higher than the cheaper gauges. Sometimes guys also take readings after the saws idled a while, the extra oil falsely raises compression readings. BTW when the saws left here they all had well over 200psi[emoji3]

 

[smokey7]

My 350/346 was bout140-150 with stock 346 p&c from memory. The 350 was a weird combo after it was rebuilt by the first dealer. It had a flat top piston in it and it also blew 145-150ish (from memory) they both ran very well considering the 350 p&c isnt the best from a performance standpoint. The 346 liked to rev just a little more. They weren't as far apart as i thought they would be.

 

[XP_Slinger]

Man this is a head scratcher. One simple thing I didn’t see mentioned was the condition of the air filter...is it plugged up? Stupid question I know

 

[Moparmyway]

It would help if you would video this happening, so we could see and hear if its lean or fat ..........
If its 4 stroking, or missing, etc .......

 

[decableguy2000]

Man this is a head scratcher. One simple thing I didn’t see mentioned was the condition of the air filter...is it plugged up? Stupid question I know

With and with out the filter same thing.

It would help if you would video this happening, so we could see and hear if its lean or fat ..........
If its 4 stroking, or missing, etc .......

Not sure how, never tried to post a video before.


Will more than likely be the weekend before I try to mess with it. Have to swim to shed, been raining since Sunday night.

 

[XP_Slinger]

With and with out the filter same thing.



Not sure how, never tried to post a video before.


Will more than likely be the weekend before I try to mess with it. Have to swim to shed, been raining since Sunday night.

It's very easy to get a video posted in here. Upload it to youtube, then copy/paste the link in the thread, if you need any help give me a shout.

 

[Dub11]

My 350/346 was bout140-150 with stock 346 p&c from memory. The 350 was a weird combo after it was rebuilt by the first dealer. It had a flat top piston in it and it also blew 145-150ish (from memory) they both ran very well considering the 350 p&c isnt the best from a performance standpoint. The 346 liked to rev just a little more. They weren't as far apart as i thought they would be.

what 350 head?

 

[sunfish]

I have had quite a few cross my bench, some were 353's some were 346's all of them had between 135psi and 150psi. Yes 140 is typical, remember the compression testers are not all equal, the Snap on gauge I have reads 10 to 15psi higher than the cheaper gauges. Sometimes guys also take readings after the saws idled a while, the extra oil falsely raises compression readings. BTW when the saws left here they all had well over 200psi[emoji3]

The lowest Ive seen on a 346 was a brand new one at 150 psi, after 10-12 tanks it was 160. My old 346 was 165 psi after 10 years of regular use. The other 7-8 saws I have were all 160 +/- 1-2 psi. Never heard of 140 psi being typical with this saw???

 

[andyshine77]

The lowest Ive seen on a 346 was a brand new one at 150 psi, after 10-12 tanks it was 160. My old 346 was 165 psi after 10 years of regular use. The other 7-8 saws I have were all 160 +/- 1-2 psi. Never heard of 140 psi being typical with this saw???

Older saws often have more compression do to buildup in the top end, which artificially raises compression a bit. Oil buildup can drastically increase compression as well, so I run the saw tuned crisp in the cut shut the saw off, let it cool down and take a reading. Saws that idle a lot or rich will give you higher readings. This series of saws has been all over the place when it come to things like this, and is one reason you can get a dog out of the box or a real runner. My personal 346 had 145psi before I remove the base gasket, it's now around 160 with .016" squish and is the best example of an otherwise stock 346 I have ever ran.

Anyway all these things can add up to giving us slightly different readings, my point was compression is likely not the issue here.[emoji6]