Carb problems even after rebuild (Homelite 330)

[magicmikeb]

I'm having problems with a Homelite 330 with a Walbro carb. It was stored away for years and I got it back out and noticed it needed a new boot under the carb so I replaced that. Then I rebuilt the carb too. When I crank it, I can get it to run if I hold the throttle all the way, but it just barely idles. I've adjusted the high and low needles all the way out and in and there is basically no change to the RPMs of the chainsaw.

I thought that I may have installed something incorrectly so I tore the carb back apart and printed a diagram and everything seems to be installed correctly. It's also getting fuel from the tank with no problems. What else can I do?

I was told by the place where I bought my rebuild kit to "throw that carb as far as you can and get a new one" but surely there's something I can do?

Thanks for any help or suggestions that you may have. I appreciate it.

And nice forum you have here by the way.

Thanks,

Mike

 

[Lawn Masters]

It sounds to me like your adjustments are totally out of whack. set the hi and lo screws in to a lightly seated position, then 1 full turn out, and try from there. not sure if thats what you meant by "all the way in and out" but it might start to help you get it idling right.

 

[2wheels]

Those saws have a bellows between the carb and cylinder that goes bad and develope an air leak. Also can cause a lean condition,causing piston/cylinder damage. If yours is original it would need to be replaced for proper long term operation. While your at it chech the rubber vibration grommets they may also be deteriated due to age.

 

[bugfart]

First, remove the H & L needle valves and inspect carefully with magnification, preferrably a jewelers loop.

You do not want to see a circular scar on either tip as this probably means the seat is punctured from over-tightening the needle-valve - and if so, go ahead and replace that carb. If they look new, the carb should be salvageable. Do not throw the carb away.

The metering is the next place I would check. If that diaphragm hat isnt connected to the fork of the lever it might conceivably do funny things. You want to make sure the idle valve is clean and not obstructed inside.

If you end up really frustrated take the whole thing and soak it in fuel mix over night. It might be gummed up worse than you thought inside.

Should anything make its way to the reed valves and hold it open, it could do that also. They could also be gummed shut.

Fuel lines seeming good means nothing, I would replace the lines and filter, stem to stern, no exceptions, you'll be glad when you're done.

Do all that and check back.

 

[2wheels]

You will want to take off the carb and clean all passages. If the saw has been sitting idle for some time. I use carb cleaner and a torch tip cleaner or guitar strings if needed.
You should not have to get inside welsh plug.

Now that you know the carb is clean. Check your bellows.

Believe me on this one as I have been there and you will be thinking it is a carb problem.

And no do not throw the carb away.

 

[magicmikeb]

Lawn Master, I started with the needles 1 1/4 - 1 1/2 turns out. I just meant that regardless of their position, it ran the same.

2Wheels, The bellows, is that the rubber boot between the carb and engine? If so, I just replaced that as it was almost gone completely. If not would you let me know which part you're talking about.

Also, I went throught the whole carb with carb cleaner and a bristle off of a wire brush but I may have missed a hole somewhere.

bugfart, I'll try what you suggested and report back.

Thanks to everyone for all of the replies...I appreciate it. I don't know of anywhere else you can get info/help like this!

Mike

 

[bugfart]

If the rubber boot (manifold) was in that state I would encourage you to clean out the reed valves. We have not talked about the pulse line that I bet ends up fixing this. Part number is 9520108 and this bad boy is either disconnected or leaking. This sends a signal to pump gas while the engine turns over.

If it isn't you have the worst seals 93858 I have ever heard of.

When you changed the manifold (bellows -boot - rubber piece of hose) you probably disconnected the narrow little 2" tube at the bottom of the carb. And sinse you have to lift the carb to fix it (I think) you might as well remove the whole deal and clean up the reeds. Treat them like angel hair.

If you want to just hook up a good sense line and run it, I wouldn't blame you, but these are the steps to making a nice idling saw. I do it to every saw I re-build. If I replace the carb kit, I go right through and out it's spinxter.

 

[046]

you've only got:

1. electrical
2. mechanical
3. fuel

now which one is it?

I've rebuilt hundreds of carbs, mostly high performance weber carbs. principles are all the same.

easiest way to tell if an orfice is clear is with a can of chemtool with a tiny hose stuck to nozzle.

don't do this without glasses!!! you will be sorry!

after blowing out passages, cleaning with chemtool etc. press tip of chemtool nozzle to each and every orfice, then spray.

if chemtool comes out other end(s) you have a positive ID passage is clear.

carefully follow carb kit instructions for setup and follow it.
alway turn your set screws to preset starting positions. then adjust from there. lots of folks here wil tell you what that is.

then follow a clear guide like on Madsen's web site to adjust.

if you do what I just posted, guarantee carb will run like new. now if carb ran like sh*t new, that's tuff

 

[bugfart]

I bet you two gum wrappers and a popsicle stick it's the pulse line.

 

[Gypo Logger]

Can someone recommend a kit that would be good for drilling carbs and where I might buy one? I haven't done this before. I am assuming that increments of 2 thou in a jet is more than sufficient when drilling.
Thanks,
John

 

[magicmikeb]

If the rubber boot (manifold) was in that state I would encourage you to clean out the reed valves. We have not talked about the pulse line that I bet ends up fixing this. Part number is 9520108 and this bad boy is either disconnected or leaking. This sends a signal to pump gas while the engine turns over.

If it isn't you have the worst seals 93858 I have ever heard of.

When you changed the manifold (bellows -boot - rubber piece of hose) you probably disconnected the narrow little 2" tube at the bottom of the carb. And sinse you have to lift the carb to fix it (I think) you might as well remove the whole deal and clean up the reeds. Treat them like angel hair.

If you want to just hook up a good sense line and run it, I wouldn't blame you, but these are the steps to making a nice idling saw. I do it to every saw I re-build. If I replace the carb kit, I go right through and out it's spinxter.

Yeah, that pulse line was a pain in the ass to get back on so I'll pull everything one more time and go ahead and replace that and clean the reeds while I'm in there. This probably won't get done till after the weekend but I'll reply back to let you know how it went. Again, I really appreciate all the help and the way you even gave me part #s. Thanks guys!

Mike

 

[046]

Can someone recommend a kit that would be good for drilling carbs and where I might buy one? I haven't done this before. I am assuming that increments of 2 thou in a jet is more than sufficient when drilling.
Thanks,
John

gypo, what you want is a weber reaming kit. it comes with tapered precision reamers. there's also a pin guage available. note: these old weber tools are kinda hard to find.

I've personally rejetted hundreds of weber carbs, custom setting up for desired flow.

a quick and dirty way to achieve close the same. if you can't find the weber kits is a pin drill set. these come in the tiny sizes you need.

can't find my weber reamers, it's buried somewhere...

here's a pic of what you need. a good set of digital calipers will help this job along. note the starett pin vise to hold these micro drills.

 

[bugfart]

Screw carburetors.
Introduce the fuel right at the plug, so screw manifolds, rubber boots, and most of all... bellows. Let the darn counterweight thwap (yinzer for flick) some other medieval pump form, creating enough pressure to activate the injector. Then we can magnetically ionize the top of the jug so the O-2 makes a better bond with the fuel at the atomic level. Squeezing the trigger acivates the cam the lever rides on to advance timing.

Saves a lot of unneccessary metal making it lighter. I'm like a hundred monkeys at type-writers, and some day I'm going to put out at least a little Shakespear.

 

[Gypo Logger]

gypo, what you want is a weber reaming kit. it comes with tapered precision reamers. there's also a pin guage available. note: these old weber tools are kinda hard to find.

I've personally rejetted hundreds of weber carbs, custom setting up for desired flow.

a quick and dirty way to achieve close the same. if you can't find the weber kits is a pin drill set. these come in the tiny sizes you need.

can't find my weber reamers, it's buried somewhere...

here's a pic of what you need. a good set of digital calipers will help this job along. note the starett pin vise to hold these micro drills.

Thanks for the information and great pictures. Now I know what I am looking for.
It's ironic because we use "Oklahoma", as an adjective here to describe anything that has been jury rigged, but you have broken that stereotype, but it's ok because the Americans must say things about British Columbia and why wouldn't they?
Anyway, thanks again.
John

 

[046]

Thanks for the information and great pictures. Now I know what I am looking for.
It's ironic because we use "Oklahoma", as an adjective here to describe anything that has been jury rigged, but you have broken that stereotype, but it's ok because the Americans must say things about British Columbia and why wouldn't they?
Anyway, thanks again.
John

nah... we've only got nice things to say about BC. only time I was there was aprox. 15 years ago visiting with friends in Goldbridge, BC.

Beautiful country!

 

[RaisedByWolves]

Gypo, We mostly pick on Quebeckers round here, though I spect regional differences.


You would have better luck finding a set of Micro number drills. these come in a set that ranges from #60(tiny) to #80(extreemly tiny).


You can find them at hobbyshops or tooling suppliers for around $15.00 us.


I lied, $8.00

https://www.micro-tools.com/store/mainframe2.aspx


Click on drills and there on this page, They call them miniwire drills.

 

[bugfart]

I admire you guys that get in there and tweek at the machining level like that. 046, great pic! As always, good worth-while content.

Can we start a tool-envy group around here for people like me? Or would we need several partitioned web sites?

Pill-poll
Do you think he plugs in the pulse line and never comes back?
I mean until it breaks again anyways... Seemed like a good nut. I say he comes back and is instantly hooked!

He is about to buy a saw on E-bay... (stay with me here - I was raised by ancient Homelitian Monks and learned the art of "distant visualation" ) wants to buy one... doesn't end at the right time for him....

That's all for now. It's time to walk behind the wood-shed and talk to God.

 

[magicmikeb]

Pill-poll
Do you think he plugs in the pulse line and never comes back?
I mean until it breaks again anyways... Seemed like a good nut. I say he comes back and is instantly hooked!

He is about to buy a saw on E-bay... (stay with me here - I was raised by ancient Homelitian Monks and learned the art of "distant visualation" ) wants to buy one... doesn't end at the right time for him....

That's all for now. It's time to walk behind the wood-shed and talk to God.

Since you were raised by the Homelitian Monks, you surely learned that distant visualization takes cues from the subjects physical presence at some point in your life. Withouth that, the chance that you misinterpret their aura is comparable to the chance that a Walbro carburetor will actually work correctly on a Homelite 330 chainsaw.

This nut WILL be back...it may just be a while until I get to work on it. And I've got the saw already although I did hit up ebay looking at carbs before I found this place...thanks again for the help and a good laugh

Mike

 

[bugfart]

It's still a whole lot better than;

"My 330 was talking to your 330 and your 330 said..."

That's the kind of stuff that drives me out of the house to work smiling all the way. Overtime? No problem, can I set up a cot?