Carb rebuilding how to ?

[countryhog]

i find that soaking them in solvent for a few days helps much

 

[junkman]

Anyone ever soak them in 50/50 atf and acetone ?

 

[junkman]

Never heard of that one,I did read somewhere on the Internet that some folks soak them in pine sol.Atf does have a lot of detergent in it.

i have unstuck rusted engines with that acetone atf ,it cleans pretty good ,old timer turned me on to that mixture .

 

[Terry Hennessy]

One of my faults is sometimes i can fix a carb ,sometimes i can not ,is there more to it than a kit and a can of carb cleaner ? sometimes they work after cleaned out ,sometimes they do not ,like my string trimmers .what am i missing besides blowing out the passages on something that will not start ? Anyone care to do a in detail how to on this subject ?

(Sometimes) what feels like bad carb, or no spark is actually low compression, so the question is, are you following a good troubleshooting procedure? I recently had one that would start 15-sec, then die; turned out to be a bent fuel line was actually crimped shut & trimming 1/8" from length cured problem.

 

[junkman]

(Sometimes) what feels like bad carb, or no spark is actually low compression, so the question is, are you following a good troubleshooting procedure? I recently had one that would start 15-sec, then die; turned out to be a bent fuel line was actually crimped shut & trimming 1/8" from length cured problem.

have had fuel lines sucking air on my husky chop saw 371k ,i bought a new carb because it would run off mix poured down carb throat but not on it's own ,took carb apart ,sprayed carb cleaner ,seemed to be going through all the passages ,but no start ,got fed up bought a new carnb ,same thing ,it had a pinhole crack where entered the tank i could not see ,shortened the hose started right up ,my string trimmer i have 2 of same model ,so can rob parts off the other for diagnostics ,1 out of 3 times on those i can seem to get the carb going again though ,new ones are about 40 bucks so my time is worth that if it is a quick fix .

 

[panteliss]

Anyone ever soak them in 50/50 atf and acetone ?

I use only acetone 100% make them like new , all the others carb cleaners , etc,etc are bullshits

 

[Terry Hennessy]

One of my faults is sometimes i can fix a carb ,sometimes i can not ,is there more to it than a kit and a can of carb cleaner ? sometimes they work after cleaned out ,sometimes they do not ,like my string trimmers .what am i missing besides blowing out the passages on something that will not start ? Anyone care to do a in detail how to on this subject ?

(Sometimes) you have a clogged port under the welch plug that wasn't cleaned (because that part was not in the kit); (Sometimes) carb was not the issue. Were full troubleshooting procedures followed? Did it kick when fuel put into carb? or has it got another problem, and carb was "assumed"? E.g. was spark checked, Was muffler pulled to inspect piston, was compression tested?

 

[panteliss]

I deep them as they are in a jar with acetone only ten minutes are enough to solve all the ethanols , rusts , etc,etc then a good air blowing ( dont be afraid the screws dont be bend from high pressure ) and then a new needle and mebrans kit and its ready to go



all theese carb cleaners , brake cleaners cant clean not even markers for small childs

 

[Terry Hennessy]

When the saw is at an idle with the throttle plate closed, there isn't much air flow across the discharge nozzle (check valve) to create a low pressure on the discharge nozzle. That's why the check valve is there, it prevents air from being pulled back into the 'wet side' of the carb.

Inside the carb, the fuel is being sucked out of the 'wet side' of the carb. It is easier to suck in air through the discharge nozzle than fuel through the metering system. Eventually, you run out of fuel and the engine quits idling.

If you have a saw that will idle for a little bit, then have the revs increase a bit (leaning out) just before it dies, that could be a symptom of a bad check valve. If you have to use the choke to get it restarted (even when the saw is already warm), that's another sign it is a bad check valve.

Unfortunately, I don't know of a way to fix the bad check valve other than putting in a new discharge nozzle. However, they're not that expensive and easy to replace.

Those symptoms of revving before dying also applied to (my) pinched fuel line to the primer; Pinched just enough to allow priming to start, but not allow normal vacuum fuel flow; Start and then die, reprime to restart; shortening line 1/8" straightened enough to get good flow, LOL

 

[Lectro88]

Don't feel bad... you not the only one this happen to.

I don't mind admitting that I goof up occasionally and don't get some carbs the first time around.
And I been doing this over 30 yrs. But.. not every day.
There are so many little things like plugged gas inlets that have 90 degree entrances or diaphragms not socketed properly in needle and seat or or I've had a diaphragm wrinkle under a cover and not realize it till tearing back into it all again. Pin hole in diaphragm or a "NEW" stiff diaphragm. Or some little orifice plugged, Or heaven forbid you have 2 or 3 things going on at once and you blew the whole day it seems on a $30. carb you coulda bought new.
Cracked gas lines, bad ignition or timing problems the list goes way further than I have touched.

 

[Chainsaw Jim]

Bump

 

[jakethesnake]

I dig this thread. I too have some of those stubborn fuggers. I’m gonna grab the little pail full o cleaner with the basket to soak them in. I’ve heard that works well. I’d rather keep one going then to buy aftermarket ones. I’ve used aftermarket ones with good success. Just my personal preference

 

[MustangMike]

I believe Wood Doctor told me that soaking them in mix for 24 hours often works (similar to other posts above).

 

[jakethesnake]

Any real reason straight gasoline shouldn’t be used to soak them

 

[Keith Gandy]

HDAseries.pdf

 

[Bilge Rat]

Straight gas will get into/ under crud and into the pores of the metal floating the crud. Do not let the gas evaporate before flushing the crud out. when the gas/solvent evaporates the crud hardens and sticks to the clean metal.
Having a surfactant, to float and suspend the crud so it can be flushed out is even as the gas evaporates tends to work better.

Kroil or Marvel mistry oil and a solvent/gas will tend to hold the crud in suspension so it can be flushed out.

This information is from gun cleaning and my 40+ years in the drycleaning business.

75% solvent/gas and 25% oil seems to get the crud.

An ultrasonic cleaner with some Luminox and water will flush out the loosened crud as a final cleanout.
Luminox is PH neutral and leaves no residue. It is for soft metals. This cleaner is for cleaning lab/medical equipment.

In the end if all else fails those little cubes of metal can be flung very hard or a long way, whatever the offending carb needs to notice your displeasure with it.

 

[Adirondackstihl]

Straight gas will get into/ under crud and into the pores of the metal floating the crud. Do not let the gas evaporate before flushing the crud out. when the gas/solvent evaporates the crud hardens and sticks to the clean metal.
Having a surfactant, to float and suspend the crud so it can be flushed out is even as the gas evaporates tends to work better.

Kroil or Marvel mistry oil and a solvent/gas will tend to hold the crud in suspension so it can be flushed out.

This information is from gun cleaning and my 40+ years in the drycleaning business.

75% solvent/gas and 25% oil seems to get the crud.

An ultrasonic cleaner with some Luminox and water will flush out the loosened crud as a final cleanout.
Luminox is PH neutral and leaves no residue. It is for soft metals. This cleaner is for cleaning lab/medical equipment.

In the end if all else fails those little cubes of metal can be flung very hard or a long way, whatever the offending carb needs to notice your displeasure with it.

Luminox.....@ $80/gal, it better rebuild and tune the carb too

 

[psuiewalsh]

 

[Bilge Rat]

Luminox was not near 80 bucks when i bought it but that was over a year ago. Less than 50 then. Found it on Amazon.
4 to 6 oz.. per gallon mix seems to work.
It cleans well and it leaves parts very clean, no residue. No turning parts black.
I agree it ain't cheap but after trying it is worth it.
Even with no rinse the parts are squeaky clean.
Look at it like this, it is cheaper than sex.

 

[Adirondackstihl]

it is cheaper than sex.

Troof!
Well......cheaper than with someone else anyway