Author Topic: Ms661c problems (Read 7377 times)

Bigbo1234 · « **on:** March 24, 2017, 05:37:41 AM »

Hey, so I'm not new here but I'm posting first time in years. I have recently moved to Kauai Island, Hawaii for a massive logging job. Cutting the worlds faster growing tree, Albizia. Bigger than anything I have cut in northern Michigan. I run Stihl Ms661c with 28" bar. It's been a pretty good saw so far. In the 4 months I've ran it it has developed a few issues though. Biggest being the computer seems to be messing up causing a loss of high end power. Maybe it's a carb issue, maybe not? Anyone have any thoughts. I have 3 diff saws
And two so far are acting up, but they do get run very hard. Upper 80's temps and 93% humidity today, burned about 4 gallons through it today. I have fallen on it, I have dropped it, I have had large logs fall on it, I have thrown it,(accidentally) and it has cut during some really heavy downpours. I have broken half the main body(twice), broken some vibe springs, broke the safety trigger, and melted the plug wire. But it seems to be holding up better than the ol' 390xp

last big issue is once warm it can me a bugger to start without holding throttle open.

Canadiana · « **Reply #1 on:** March 24, 2017, 06:54:09 PM »

Well if that didn't finish it off you might need a sledge hammer😉. Nothing obvious comes to mind but i will follow to see what you learn

DelawhereJoe · « **Reply #2 on:** March 24, 2017, 07:10:54 PM »

It sounds like your poor saw needs a vacation, any idea if theres a pin hole or hair line fracture air leak from all the abuse it has received could be running slightly lean at high rpm's.

Bigbo1234 · « **Reply #3 on:** March 24, 2017, 07:35:24 PM »

Well it's sounds like I'm harder on my saw than I really am. Most instances of damage are due to the cutting we're doing. Chasing and bucking 4-6 foot diameter trees for 9-10 hours a day in the field. Lots of trip hazards, and these trees can have tension that removes the saw from your hand really fast and throws it. The only time I used my muscles to throw the saw was when I had a large cane spider crawl up on my throat while cutting. Now I don't recall throwing it but it was in my hand and then it was not. The saw is currently 3-4 months old and day to day it cuts 7-10 hours. I eat a chain in about a week. But we are clearing anywhere from 3-10 acres of rainforest a day. I'm on break right now but today the saw seems better, through it has still had a few weak moments.

Texas-Jim · « **Reply #4 on:** March 24, 2017, 07:50:53 PM »

Actually saws arent designed to be started at idle, it should be in warm start position.

Bigbo1234 · « **Reply #5 on:** March 24, 2017, 08:04:02 PM »

Every time or just first start?

Texas-Jim · « **Reply #6 on:** March 25, 2017, 07:10:19 PM »

The non M-tronic saws are designed to be started in the warm start position. Use the choke on cold start but use the one first up from choke for warm starts. All two strokes start better with touch of throttle. I dont always do it but if i have saw that likes it i do it.

air1514 · « **Reply #7 on:** April 12, 2017, 10:02:32 AM »

Sounds like you have a leak somewhere in the saw. You should do a vacuum leak down test. My 661 always acts like it's running real rich. I think I need to take it to the shop and have them adjust the carb. I'm assuming that they can but I'm not sure how

mikereiche · « **Reply #8 on:** May 15, 2022, 05:36:01 PM »

When hot, my ms661 starts better on full throttle. Also I have found that the choke is sometimes stuck closed.

Coopthecutter · « **Reply #9 on:** May 15, 2022, 05:55:55 PM »

X2 checking for air leaks. Also my memory is a little fuzzy on this but I believe some of the older model 661Cs had an issue starting hot due to the ignition module? Or some sort of faulty computer part in the M tronic system. I have a 661c that's over 2 years old and has been run pretty hard, no issues with it starting. Can you post some pics of these trees you're cutting? Sounds like a really cool project!

dave86 · « **Reply #10 on:** May 25, 2022, 11:46:22 AM »

Quote from: Bigbo1234 on March 24, 2017, 05:37:41 AM

Hey, so I'm not new here but I'm posting first time in years. I have recently moved to Kauai Island, Hawaii for a massive logging job. Cutting the worlds faster growing tree, Albizia. Bigger than anything I have cut in northern Michigan. I run Stihl Ms661c with 28" bar. It's been a pretty good saw so far. In the 4 months I've ran it it has developed a few issues though. Biggest being the computer seems to be messing up causing a loss of high end power. Maybe it's a carb issue, maybe not? Anyone have any thoughts. I have 3 diff saws
And two so far are acting up, but they do get run very hard. Upper 80's temps and 93% humidity today, burned about 4 gallons through it today. I have fallen on it, I have dropped it, I have had large logs fall on it, I have thrown it,(accidentally) and it has cut during some really heavy downpours. I have broken half the main body(twice), broken some vibe springs, broke the safety trigger, and melted the plug wire. But it seems to be holding up better than the ol' 390xp last big issue is once warm it can me a bugger to start without holding throttle open.

Is the wood being used for commercial purposes?

beenthere · « **Reply #11 on:** May 25, 2022, 03:14:49 PM »

Dave
Bigbo has not been active for 5 years.

Maybe try to send Bigbo1234 a personal message to get an answer.

Spike60 · « **Reply #12 on:** May 25, 2022, 08:22:56 PM »

Yup, it's easy to get tripped up and not notice a thread is revived from several years ago.

Got a kick out of DelawareJoe's comment about the saw needing a vacation while it's already in Hawaii.

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