C-72....well you know

[jerseyhighlander]

Just watched the video again. Your choke lever came of and is just floating there.

[Deleted]

No it didn’t come off I just didn’t hook it back up while testing but it isn’t moving it remains open.

[Deleted]

Well I got an update on my carb today. There has been a change in the needle (or so the tillotson rep says) and if you do not change needle with seat it will not seal correctly. Something about the rubber seal is on the needle now. Also I’ve been told that the throttle shaft had too much wear and slack and allowed for more air flow from outside to come in around the shaft. It’s on its way back to me now I guess I will see. Hopefully have it back by the weekend. I did leave the old seat in one of the carbs, not sure about the other. I will decide later how fair the price for repair is if it works and I don’t find any other problem 😂

[Deleted]

I also got my new mightyvac 8500 in and with the plates I made the other day at work I checked my reed valve for sealing and it doesn't. It won't build a vacuum much less hold one nor will it hold pressure. I am guessing it should hold a vacuum or pressure either way but I am open to any info there too. Meanwhile I will be trying to figure out how to clean the seat for the reed and see if it makes a difference. Just to be more clear I built a plate for each side as I know the reed opens to allow flow in so I tried to pull a vacuum on the carb side and pressure on the crankcase side both directions failed

[lesorubcheek]

Not sure if a reed would actually seal enough to pull a vacuum or hold pressure. The way I test is to have it removed from the saw, blow through the carb end. It should sing just like a reed in a clarinet... well maybe not exactly, but it'll sing. I was never into wind instruments. Suck from the same end and it should slap back and offer obvious resistance. Again, I don't think you could really suck a vacuum, but it won't just hiss with air either. May seep a little. Depends too if it's dry or has a little oil around it. I'd post a video, but the whole mouth thing is a little weird. It's not easy to describe with words.

Dan

[5terrysupersaws]

The reed seat has a chip/pit/crater preventing it from sealing that I can see in a magnified image viewed on a large screen..try your other reed valve assembly to see if it passes your vac/press test.or post an image of that one..also a fleabay seller has a NOS reed valve assembly A-59490 for $ 18.99....that would solve the issue of fuel being sprayed out the back of the carb.

[Deleted]

Jan 31, 2018 22:05:10 GMT -5 5terrysupersaws said:

The reed seat has a chip/pit/crater preventing it from sealing that I can see in a magnified image viewed on a large screen..try your other reed valve assembly to see if it passes your vac/press test.or post an image of that one..also a fleabay seller has a NOS reed valve assembly A-59490 for $ 18.99....that would solve the issue of fuel being sprayed out the back of the carb.

Thanks may check that out. I tested both reeds neither one is holding vacuum or pressure. 🤨

[jerseyhighlander]

That's good news, kind off. Sounds like they found more than enough of a problem with the carb to account for the trouble you've been having. It's on it's way back having been repaired? You should be good to go after that. Sounds like the rubber seats came out of their socket and were stuck on the end of the needle. That would make it pretty much impossible to adjust.

I wouldn't expect the reed to hold a vacuum. It's just supposed to block the bulk of flow going back to the carb. Certainly shouldn't resist pressure, it has to open to let air/fuel through. Cleaning I'd just use a toothbrush with some carb cleaner, maybe scrape the gunk out of crack with an Xacto knife or something if it's stubborn, but try to let the carb cleaner jet do most of the work. Maybe a light scrub on the reed seat with a scotch-brite and some WD-40. No need to get crazy there, it doesn't look like it was the problem to begin with.

[Deleted]

Here's some pic of the other reed I have, it looks much better. I must admit I don't know whether to be impressed or embarrassed at the fact you saw those defects by a picture of the reed when I am holding the actual reed in my hand. Maybe I should look into an appointment with the eye dr. first then continue with the saw lol. Anyway as far as the needle and seat goes he said something about the new needles use a hard rubber almost plastic type seal on the tip of the needle and the seat is the solid metal whereas before the rubber seal was in the seat. Since that has been reversed if you use a new needle with the hard plastic or rubber almost tip, it won't seal against the old rubber seat. I am just relaying what he said I don't remember what he told me the seat was made out of. That's the unfortunate part about being maintenance supervisor on a high volume frame production line. I can have my phone to one ear and the radio and my name is being yelled into the other.

www.flickr.com/photos/138659658@N05/shares/drn148


ah hem...yes that gasket is terrible, I have a new one I was using with the other reed and another new one (I think) in an envelope in my toolbox both of which were shipped all the way to Mississippi from Oregon ;-)

[5terrysupersaws]

No need for any embarrassment I'm viewing the image magnified on a 50" screen...the reed seat is the size of a large dinner plate,lol

This reed assembly looks good..gentle cleaning/new gaskets...should be good to go.

[jerseyhighlander]

Takes more of a man to admit you goofed, even while trying to do something new with the rest of life still happening all around you. Any one of us that says we've never done anything boneheaded or got ahead of ourselves on something unfamiliar is lying. It's all part of the process, turns into experience while you sleep. Glad you're getting it worked out.

That reed seat does look a lot better.

Just for clarity, your talking about the Hi & Lo adjustment needles or the metering needle inside?

[Deleted]

Metering lever inside

[jerseyhighlander]

Feb 1, 2018 6:31:03 GMT -5 jselden78 said:

Metering lever inside

Don't know why I was stuck on the adjustment screws/needles. You aren't the first to be bit by that bug and won't be the last. From what I understand, and I think it is from watching one of Leon's videos about rebuilding these carbs, given how long that design was in use, that valve seat used to be a rubber seat jammed down in that hole and the needle was all metal. At some point they changed it and formed/machined the seat into the metal carb body and the tip of the needle became rubber, easier to replace.

I've not worked on one of these yet, does anyone know how this is resolved when you have the older version with the rubber seat? Can they be pulled out and a new one put in (are replacements even available?) or do you hope the seat is ok and make sure to get a kit with the all metal needle? I've got a couple of these in the line up for future work.

[Deleted]

Is this situation on all new carbs,or just a select few?

[Deleted]

I have weird vision problems, so I make mistakes all the time, I used to beat myself up about it, but with a hobby, I have to let it go and be okay with it.

[Deleted]

My vision problems aren't really weird,they're just aggravating because I can't see"normal"anymore.I haven't been able to drive since 1992.My left eye can only be corrected to 20/70 & couple that with very little peripheral vision & I'm quite entertaining to say the least.That's why I have such a hard time doing carbs - those little springs go flying & then I get pissed because I can't find them.Lol

[Deleted]

Not sure about all carbs but I know it is on a HL141D. I remember on one of them I left the old seat in and the other I changed the seat. I am not sure after all the trouble afterwards and swapping parts which was which in the end. I do know too when I removed the old seat, the old seat was longer than the new seat and that did concern me but I tried it anyway. I still don't have the carb back yet to try it but hopefully tomorrow or Saturday I will have it back and try it out.

[Deleted]

And I thought that I was the only one here who had carb issues.I still haven't rebuilt one yet that has worked & I have about 20 or 30 more that need rebuilding.
    Best of luck to you when you get it back & try it out.

[Deleted]

I’ve had good luck with rebuilding the walbros, I have a Zama on the bench I just haven’t gotten to yet but that tillotson has been a battle for awhile now. Hopefully all that’s over. If it turns out good when it gets here I will fill y’all in more on who I outsourced that to

[Deleted]

I've been following this since the beginning.I think that between the reed valve & the carb issue you've got this taken care of now.