High Quality Chainsaw Bars Husqvarna Toys

Odd 462 MT Problem

drf256

Dr. Richard Cranium
GoldMember
Local time
1:11 AM
User ID
319
Joined
Dec 29, 2015
Messages
9,334
Reaction score
61,428
Location
Strong Island NY
Country flag
Having an odd MT problem with a 462. Saw has been ported and Muffler Modded, but ignition timing untouched.

Saw purchased used from a dealer with 58 minutes of run time as per the computer when plugged in. Saw was nearly perfect inside and out. Dealer (whom I fully trust) ran saw stock and found zero issues-which means there weren’t any. The saw only shows the issue after 4 or 5 long cuts, so it’s possible the dealer didn’t run the saw enough for it to show.

The saw was pulled apart for a vacuum and pressure test after the issue. No leaks found. The exhaust is a bit challenging to block off on the model with its odd structure. Flywheel pulled to insure key didn’t shear-it did not.

Pump side of carb opened to insure no debris got in and plugged up screen. Looked perfect without debris.

Saw ran on 2 different mixes at 40:1. Both Efree with Motul800 and VP with Saber. Did same thing on both mixes.

The throttle linkage is not sticking. If it were, slowing chain speed by putting load on it wouldn’t change things (unless the MT could compensate for that-I guess that’s possible).

Did factory V2 reset 3X. Made no difference.

I am a bit perplexed. Any help appreciated. I tighten down the carb snugger after pulling it a part a 3rd time, but ran out of daylight for retesting. Next I plan on pulling the handle to inspect the linkage rod.

Here’s the saw. 25” 3/8 7pin in poplar test log. It’s hero wood, but I’m not gonna ruin a good oak log for testing, the poplar has no other use for me. Fast forward to 2:30 to see the issue.

 
Last edited:

DND 9000

Pinnacle OPE Member
Local time
6:11 AM
User ID
800
Joined
Feb 6, 2016
Messages
725
Reaction score
1,617
Location
Germany
Country flag
Have it checked at the dealer (complete test at the computer), especially the fuel numbers. Sometimes strange things happen. Also let the dealer check the carb/solenoid valve (pressure test). On the picture it looks like the carb is an 1142/01? Not clearly visible.
 

drf256

Dr. Richard Cranium
GoldMember
Local time
1:11 AM
User ID
319
Joined
Dec 29, 2015
Messages
9,334
Reaction score
61,428
Location
Strong Island NY
Country flag
Didn’t take many carb pics. Saw was purchased, used and returned for reasons besides it’s performance or function.

I will send to dealer for testing after I retry the saw.

FWIW, my other MT saws run fine on the mixes I used.
 

DND 9000

Pinnacle OPE Member
Local time
6:11 AM
User ID
800
Joined
Feb 6, 2016
Messages
725
Reaction score
1,617
Location
Germany
Country flag
Sometimes a fuel/oil ratio below 50:1 (like 40:1, 32:1) can give trouble, depending on the viscosity of the oil, maybe it`s a possible reason. Also which m-tronic version is this saw? See the version on the front hand guard sticker, circle in the picture. Also what is written on the control unit?
upload_2020-2-17_13-11-39.png
 

ChipsFlyin

OPE Platinum Member
Local time
1:11 AM
User ID
1244
Joined
May 5, 2016
Messages
813
Reaction score
5,787
Location
Pittsburgh
Having an odd MT problem with a 462. Saw has been ported and Muffler Modded, but ignition timing untouched.

Saw purchased used from a dealer with 58 minutes of run time as per the computer when plugged in. Saw was nearly perfect inside and out. Dealer (whom I fully trust) ran saw stock and found zero issues-which means there weren’t any. The saw only shows the issue after 4 or 5 long cuts, so it’s possible the dealer didn’t run the saw enough for it to show.

The saw was pulled apart for a vacuum and pressure test after the issue. No leaks found. The exhaust is a bit challenging to block off on the model with its odd structure. Flywheel pulled to insure key didn’t shear-it did not.

Pump side of carb opened to insure no debris got in and plugged up screen. Looked perfect without debris.

Saw ran on 2 different mixes at 40:1. Both Efree with Motul800 and VP with Saber. Did same thing on both mixes.

The throttle linkage is not sticking. If it were, slowing chain speed by putting load on it wouldn’t change things (unless the MT could compensate for that-I guess that’s possible).

Did factory V2 reset 3X. Made no difference.

I am a bit perplexed. Any help appreciated. I tighten down the carb snugger after pulling it a part a 3rd time, but ran out of daylight for retesting. Next I plan on pulling the handle to inspect the linkage rod.

Here’s the saw. 25” 3/8 7pin in poplar test log. It’s hero wood, but I’m not gonna ruin a good oak log for testing, the poplar has no other use for me. Fast forward to 2:30 to see the issue.

That little blip at 1:40 sounded weird. Was the problem maybe starting back that far? Hogging, soft cuts, hogging + pushing limits with mods. Maybe the M-tronic said What?!? I can't keep up.
 
Last edited:

Spladle160

Pinnacle OPE Member
GoldMember
Local time
1:11 AM
User ID
8753
Joined
Feb 18, 2019
Messages
504
Reaction score
1,728
Location
NOVA
Country flag
I've heard of an identical problem on either a 261 or 241 don't remember which and don't know if it was ever solve but it was the same symptoms. Seemed to run fine then the "throttle would stick" wide open for lack of a better or more accurate description. I guess you could run it with the top cover off to ensure the throttle isn't sticking in that fun house slide linkage but it seems unlikely. how cold was it? Carb froze open?
 

Manofstihl661

Pinnacle OPE Member
Local time
1:11 AM
User ID
2206
Joined
Nov 30, 2016
Messages
913
Reaction score
2,876
Location
Texas
Country flag
I’m not expert by annnyyyy means. But it sounds like it’s pulsing a bit unusually at idle right at the beginning. Don’t recall any of mine, mtronic or not, doing that. Maybe a fuel issue? Although it does always seem to come back to a solenoid :/

Then the next item of business is do you have enough Magnum stickers on it?
 

EchoRomeoCharlie

Well-Known OPE Member
Local time
12:11 AM
User ID
8630
Joined
Feb 4, 2019
Messages
21
Reaction score
87
Location
South Central Wisconsin
I’m not expert by annnyyyy means. But it sounds like it’s pulsing a bit unusually at idle right at the beginning. Don’t recall any of mine, mtronic or not, doing that. Maybe a fuel issue? Although it does always seem to come back to a solenoid :/

Then the next item of business is do you have enough Magnum stickers on it?

Agree, saw seems to pulse at start up(wasn't sure if that was him messing with the throttle or not though.)

Are you sure this is a V2 saw?

Maybe try a V3 reset on it.
 

Spladle160

Pinnacle OPE Member
GoldMember
Local time
1:11 AM
User ID
8753
Joined
Feb 18, 2019
Messages
504
Reaction score
1,728
Location
NOVA
Country flag
It's got to be getting extra air above idle air to run that fast right? So other than a leak the the throttle plate has to be open more than intended? new saw, stick bits, heat and expansion?
 
Top