What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Rocket Man

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Where you really run into an issue is where the equipment uses a little rubber diaphragm to pump or regulate fuel.

Most mowers are just gravity feed into the carb, then just your standard venturi effect through the jets.
Those don't really have an issue, unless you store it with fuel in the carb.

With trimmers and chainsaws, you have a metering diaphragm that goes bad.

Say on my chain saw, it's common for it to sit for long periods unused.

I always try and test it before i take it out to loan it or what ever.
I try and keep a minimum of two carb kits on hand for it... lol

If i let it sit with fuel, then i usually need to slap in a new diaphragm at a minimum.

My boat, is a 4 cylinder 1800cc (iirc) two stroke.
It has to pull fuel from a larger tank that sits lower than the engine.

It has two diaphragm fuel pumps.
Those go hard and you end up running lean if you're not on top of it.

Pure gas in theory makes it las longer.
But those diaphragms get replaced yearly, along with the water pump impeller.
Should buy Stihl. I have had my Stihl chainsaw and weed eater for 10-15 years also, also with zero problems. I leave them full in the winter. Never an issue, they both start with 1-2 pulls every spring.
 

George B

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Where you really run into an issue is where the equipment uses a little rubber diaphragm to pump or regulate fuel.

Most mowers are just gravity feed into the carb, then just your standard venturi effect through the jets.
Those don't really have an issue, unless you store it with fuel in the carb.

With trimmers and chainsaws, you have a metering diaphragm that goes bad.

Say on my chain saw, it's common for it to sit for long periods unused.

I always try and test it before i take it out to loan it or what ever.
I try and keep a minimum of two carb kits on hand for it... lol

If i let it sit with fuel, then i usually need to slap in a new diaphragm at a minimum.

My boat, is a 4 cylinder 1800cc (iirc) two stroke.
It has to pull fuel from a larger tank that sits lower than the engine.

It has two diaphragm fuel pumps.
Those go hard and you end up running lean if you're not on top of it.

Pure gas in theory makes it las longer.
But those diaphragms get replaced yearly, along with the water pump impeller.
I run my saw out of gas after the season is over or if it will sit more than 30 days.
I have always stored my equipment dry with no gas in them.

I do run on non-ethanol premium tho too.

But nit the boat, thats a good point about the boat.
 

89Suburban

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Should buy Stihl. I have had my Stihl chainsaw and weed eater for 10-15 years also, also with zero problems. I leave them full in the winter. Never an issue, they both start with 1-2 pulls every spring.

I run my saw out of gas after the season is over or if it will sit more than 30 days.
I have always stored my equipment dry with no gas in them.

I do run on non-ethanol premium tho too.

But nit the boat, thats a good point about the boat.



I am a big Echo fan. I run this fuel in my 2 strokes, 95 octane premix with stabilizer. I get it cheap from my job:





For my straight gas lawn tractor and 2 stroke Evinrude I run 89 octane and this year round. I even run some through the Hoe from time to time:


 

07Burb

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iamdub

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Their trimmer kicks butt! Very torquey! Runs very strong. Just firing it up and idling gives me a b-o-n-e-r. :)

My SRM-210 trimmer looks like hell but always fires up and has plenty of power. I got it 12+ years ago from a neighbor who got it off the side of the road. It fell off a lawn trailer when a truck passed and skidded under his truck, between the wheels. It didn't run long for him cuz he ran it with no air filter (lost when it fell and he didn't know any better). I cleaned the carb and bought a new air filter and cover and have been wielding it ever since. Once warm, I can start it by pinching the pull handle with my finger and thumb and giving it a very half-assed little yank, maybe one or two compression stroke's worth.

My PB-500T backpack blower (gift from ex-wife) seized after very little use- easily less than 10 hours. I broke it in per manufacturer's specs, always let it warm up and cool down, etc. I rebuilt it and started running 32:1 ratio using synthetic oil and high octane gasoline.

Both barely smoke and it's only visible at idle. 32:1 is a hair too strong but it's harmless and really easy to measure out so I run with that. Between that and the high octane, I've noticed smoother and higher revving from both.

I'd say Stihl is king, but Echo is close in reliability for considerably less cost.
 

swathdiver

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Took the throttle body off, some of the bolts and nuts were a little loose and cleaned the throttle body on both sides. It was filthy. I've cleaned it before without removing it a few times but did the back side today. Fired right up fine afterwards. I'll make a test run later.

The PCV air inlet hose o-ring, not so sure it is sealing well. RA has the whole piece for $6 so might put one on the next order. Really, just need the blue o-ring.

Daughter a few months ago put some kind of wax on all the black plastic trim. Looked good for a while and then turned everything white. Now that my strength is returning, I went out yesterday and scrubbed the grill and passenger running board and got about 2/3 of the stuff off. Couple more afternoons and I should have made it around the car.
 

George B

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My SRM-210 trimmer looks like hell but always fires up and has plenty of power. I got it 12+ years ago from a neighbor who got it off the side of the road. It fell off a lawn trailer when a truck passed and skidded under his truck, between the wheels. It didn't run long for him cuz he ran it with no air filter (lost when it fell and he didn't know any better). I cleaned the carb and bought a new air filter and cover and have been wielding it ever since. Once warm, I can start it by pinching the pull handle with my finger and thumb and giving it a very half-assed little yank, maybe one or two compression stroke's worth.

My PB-500T backpack blower (gift from ex-wife) seized after very little use- easily less than 10 hours. I broke it in per manufacturer's specs, always let it warm up and cool down, etc. I rebuilt it and started running 32:1 ratio using synthetic oil and high octane gasoline.

Both barely smoke and it's only visible at idle. 32:1 is a hair too strong but it's harmless and really easy to measure out so I run with that. Between that and the high octane, I've noticed smoother and higher revving from both.

I'd say Stihl is king, but Echo is close in reliability for considerably less cost.
A little extra oil never hurt these engines.
The Husqvarna stuff seems good too
 

swathdiver

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Just got back from Chevron, $144.68 for 27.3 gallons of 93. A new record! I plugged in the OBDII adapter and fired up the Torque Pro app on the way to the gas station. LTFTs were at ZERO for most of the drive which is a first for this truck. Tightening those bolts and nuts on the throttle body must've done the trick. Same thing on the way home after the computer re-computed for the new fuel, which was same as before, .34% ethanol. Truck was getting 23-24 mpg at 66 mph! She never done that before! Happy Camper!

Oh, an no more cutting out, tightening the positive cable on the battery did the trick! Right before this happened I took the adapter off the terminals for the Battery Tender for reasons lost to me and forgot that I did it! The terminals were obviously not tightened enough and caused these gremlins since March.
 
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Doubeleive

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Yesterday i changed the filter to inspect and getting ready for another breakin run.

Running the fresh transmission through it's paces, and seating those fresh piston rings.

Then while getting ready for a drive up the canyon, i went to connect my phone via blue tooth to the radio.

I tried to set the audio input on the deck (pioneer avic 5201), and suddenly it freezes.
Then reboots.
Then gets stuck in a reboot loop.

Turns out this is a documented issue.

They use a sd card to run the software on the deck.
Over time, that sd card can fail and become corrupt.

So i took the radio out, pulled off the front panel to find the sd card.

Hoping i can recover something, especially since that radio is how i find our property... ugg.

Anyways, luckly there are a few that have figured this out on some forums, and even sell replacement sd cards loaded with the factory software.
ya I recently replaced the sd card in the wifes pioneer deck, unfornutely when you do that it has to be factory reset the old card is ***** junk, they fail just like hard drives. her's was not a navigatiion unit so not sure if the gps data would be affected or not, you might be able to replace the software sd card boot up and retrieve gps cordinates before resetting it, if you do not reset it then it's like a frankenstien job
if you carry a android phone you can go into google maps and hit the menu button and look at your location history it may have the gps data as well even if there is no cell service.
 

iamdub

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A little extra oil never hurt these engines.
The Husqvarna stuff seems good too

Nah. The weaker mix ratios reduces emissions, but at the expense of engine life. Some of the newer stuff can clog if there's too much oil.
 

George B

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Nah. The weaker mix ratios reduces emissions, but at the expense of engine life. Some of the newer stuff can clog if there's too much oil.
I have seen that happen too.
I have to have two mixes on hand. 16:1 for my old LawnBoy mower and then 40:1 for everything else. My Stihl saw takes 40:1 and all my Echo stuff is 50:1. I refuse to mix three cans of gas. They all run great.
 

Fless

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I'm a bit surprised that modern 2-cycle engines aren't designed with a separate oil reservoir and an oil pump, like my first motorcycle, the old Kawaski 350 twin. Maybe it's lack of space or too many additional parts, but it sure would be more convenient if the pump metered the oil and you didn't have to mix.
 

RooTBeeRthe1st

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I'm a bit surprised that modern 2-cycle engines aren't designed with a separate oil reservoir and an oil pump, like my first motorcycle, the old Kawaski 350 twin. Maybe it's lack of space or too many additional parts, but it sure would be more convenient if the pump metered the oil and you didn't have to mix.
A lot of those in the 70s and '80s were designed that way, a separate oil tank and injection pump.
And a lot of those systems had issues and would end up starving the engine and seizing it.
But I'm sure also like you said, additional parts, complexity, and weight.
 

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