Tillotson HL Carb Rebuild w/pics

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Could you bolt one of these on there??

TwinHL1.jpg


This is a set of HLs I rebuilt for a 252cc JLO mounted on an old SkiDoo.
You can see that one lever actuates the second carb like secondaries
on an automotive carb. Yeah the velocity stacks aren't very practical
on a saw...... Twice the carbs, four times the tuning headaches.

Just one piece of advice, DO NOT assume that all needles are the same
length. Genuine Tillotson kits may be, but aftermarket kits vary wildly.
Using the old lever setting is a good shortcut with equal lenght needles,
but if you don't check the needles length you will go nuts trying to find
the problem.
 
Hey Gary. Would you happen to know the initial settings for a HS Tillotson? My computer does not care much for Tillotson's web site. I keep getting a message that it is unable to load the graphics conversion filter. Thanks again for a great tutorial.

Vince

You bet Vince...

H screw out 1 1/4 turns and the L screw out 1 turn. Initial adjustments for the HS as per the Tillotson service manual... :)

Gary
 
Just one piece of advice, DO NOT assume that all needles are the same
length. Genuine Tillotson kits may be, but aftermarket kits vary wildly.
Using the old lever setting is a good shortcut with equal lenght needles,
but if you don't check the needles length you will go nuts trying to find
the problem.

Good piece of advice... That is exactly why I recently posted about the 2 Tillotson kits I used. The 113 had a different needle and seat where the 88 has the same needle and seat as the old carbs. The 113 kit was a factory Tillotson kit. I was told by who I got it from that it was a newer "Improved" design.

But I'm stickin' with the 88's for now on. :)

Gary
 
You bet Vince...

H screw out 1 1/4 turns and the L screw out 1 turn. Initial adjustments for the HS as per the Tillotson service manual... :)

Gary

Appreciate that Gary!
:wave:
.......................................... :wave:
......................................................................................:wave:
 
Hello I'm new here and have been following this thread for a while as I try and tune an HL 166 I have grafted to my son's mini bike ( I can hear the growning please bare with me )


This carb ( and all others like it ) I have ever encountered seem to work just fine in any possition. So I assumed I could mount it standing up and gavity feed it fuel ( with the pulse fitting hooked up to the intake port of a 4 stroke Honda Clone ).

I need to run it significantly richer on the L jet to get any throttle response.
the carb goes from rich to lean leaning it about 30 deg from one side to the other. last run before the header was much better than this although the idle jet was so rich it had a serious miss at idle. Now with reduced back presure everything has changed again and as you can see its worse.

I stripped the carb and check everything again the carb is used and not rebuilt but nothing inside is worn (might the diaphram be a bit stretched and old not sure how to check this ? )

Carb settings change everytime I start the engine so I have to constantly adjust it. I think I may have an airlock issue inside the metering chamber.

Lastly It burns fuel like the second coming.

I am way out on a limb here asking about an aplication of a saw carb that has nothing to do with saws but I hope some of you might have some input for me.....

I do have some saws my old John deere and Clinton. Both run fine knock on wood lol.

Video speaks far better than enything else so I have up loaded some test runs to try and find some advice. Any help would be great apreciated

http://www.youtube.com/watch?v=4T7sADPCIWE&feature=channel_page

Connor
 
HL carb advice needed

Hi Gary

Once again an excellent tutorial congrats there. I'm having some trouble out of an HL carb, maybe you can help me shed some light on the problem. I have an old poulan 71 A saw. The problem is that's not getting fuel. I have had the carb off three times now. It is super clean inside with no crud any where. I replaced the black fuel pump diaphragm, but not the other brown fiber looking one. The last time I took it apart I noticed that the brown
diaphragm had those two flap pieces curled up. Is it possible that's the problem? Should I start over with an all new kit on this one? The needle is not sticking and looks ok. Also I was wondering about that tiny brass plug between the mixture screws? What is it for? There is also another brass plug that looks like some sort of jet on the side of the carb. It's just below the mixture screws, and has an 8 stamped into it. See link below for a pic. Note I removed that small brass plug to look in there but I do have it.
I'm a Stens small engines parts dealer. I can order the diaphragm kit for $ 2.51 but it doesn't have the needle and seat. I hate to buy an expensive kit and then have the same problem still.

http://cmasalvage.com/71a.jpg


Thanks Mike
 
Mike,
My old C72 Homey would idle fine but go lean in the cut. Pulled the HL Tilly and found the brown "snake skin" fuel pump diaphragm flappers all curled up. Replaced with a new black diaphragm and the saw runs perfect again. My guess is the ethanol in the fuel is causing the flappers to curl. I would also guess that when the flappers curl they don't pump fuel as well and can't keep up with demand at WOT so it just runs out of fuel in the cut. Not good for piston/cylinder life! Anybody seen this before? Are the black vinyl looking diaphragms any better at not curling than the old snake skins?
 
Connor,
Check the metering diaphragm for stiffness. If it's old and stiff it can hold the needle valve open pressurizing the metering cavity and forcing fuel out the jets. Fired up one my old homies that had been sitting awhile and it ran rich to point where fuel was dripping out the throat of the carb. Pulled it apart and the metering diaphragm was stiff like leather. New metering and fuel pump diaphragms was all she needed.
 
The fuel pump gasket "flappers" serve as check valves to keep the fuel moving in the proper direction. They have to be flat or you won't be pumping any fuel into and through the carb. You can buy the individual gaskets & diaphragms if you like. It is easier just to buy the repair kit which should come with a new needle & seat valve. It would be nice if the kits would come with a new metering lever spring & fuel screen.:chainsaw:
 
Connor,
Check the metering diaphragm for stiffness. If it's old and stiff it can hold the needle valve open pressurizing the metering cavity and forcing fuel out the jets. Fired up one my old homies that had been sitting awhile and it ran rich to point where fuel was dripping out the throat of the carb. Pulled it apart and the metering diaphragm was stiff like leather. New metering and fuel pump diaphragms was all she needed.

Thank you for the tip.
I found the problem was the way the arm was set up and now it run pretty good. the tutorial realy helped.

Thank you
Connor
 
Yes the kits I can order for 2.50 are not compatible with the E-20 or E-85 ethanol fuel. From the picture in my book it looks like that snake skin diaphragm. Call me broke, I just don't want to spend 25 bucks on some one else's kit and have the same no fuel problem. I would much rather spend 2.50 and have the same problem, and it it fixes it that would be great. Thanks for the info. I feel better now that that one diaphragm is what is causing the trouble. I usually have good luck with rebuilding carbs but every once and a while I get a problem carb, and nothing seems to work out good with those. :chainsaw: Does any one know what the deal is with those two brass plugs by the mixture screws? The bigger one looks like a jet to me?
 
Hi guys I was digging through my stash of rebuild kits this evening and I think found a kit for the HL, needle, seat and everything. Will try installing the kit this weekend and see what happens. :chainsaw:
 
Bump... was asked about this by a few members... here ya go.

Read about where I went back and pulled the carb and used the originl RK-88 kit instead of the one I actually used in the tutorial. It's towards the end of the thread. Then go to the beginning...

:cheers:

Gary
 
Thank You Gary for this great thread! :bowdown:

I'm in the process of rebuilding one on my Homey 2100.

What is a safe way to get the gasket etc. off?

Some of it came off fine but others part were stuck pretty good.

I though I would ask before I tried anything as I didn't want to scratch anything up and have things not seal correctly.

Thanks again Gary. :cheers:
 
Bump... was asked about this by a few members... here ya go.

Read about where I went back and pulled the carb and used the originl RK-88 kit instead of the one I actually used in the tutorial. It's towards the end of the thread. Then go to the beginning...

:cheers:

Gary

Hi

i have a homelite xl-800, the carb says h326a, but i am not sure what gasket kit to buy for this.
can you help me with this.

thanks:greenchainsaw:
 
Hi

i have a homelite xl-800, the carb says h326a, but i am not sure what gasket kit to buy for this.
can you help me with this.

thanks:greenchainsaw:

hate to tell u but my carburetor parts diagram for the xl800 and the xl700 and the xl800am shows a carb homelite part # A-63448 which is a tillotson HS-26A i dont see any where it shows a H326A that 3 is a S your kit you need for that carb is located here

http://www.cmsmallengines.net/tillotson-carburetor-kit-rk23hs-rk-23hs-rk23-hs-.html

thanks
calvin
 
Last edited:
I run a Tillotson HL314G on my Open Modified Honda GX-200 Kart engine. It's got the .890 Venturi, and 1.000" throttle bore. Great carbs, great for power!
I have to rebuild about every 5 running hours however, dont know why, we just have to rebuild them more often on 4 strokes...the metering dipahragm becomes very stretched.
The only thing Im not sure about on your rebuild is why you arent using the new style captivated needle with the new style captivated metering level? They were in unison, great results doing it that way. I tried your way on accident the first time I rebuilt mine, and it wouldnt tune, even with the pop-off set at 10lbs, it wouldnt tune..
Also, why arent you setting your pop-off? Correct pop-off is the key to a tilly Being off by just a couple pounds can make it not run properly..lean out at high demands, flood at idle, etc.

If you ever want a good price on some stock kits, apskarting has a full array of all Tillotson HL and HG carb kits, from shutters, to kits, to pump bodys, carb bodys, inlets, screens (brass and SS). If you ever want to dabble in hopping one up...ecdistributing makes an array of trick parts for them, from a custom diaphragm that reacts faster, high flow needle and seat, trick pump skins, you name it! Also, if you ever want to talk to the Tillotson master, they have a forum where you can talk to E.C Birt himself.
Ive got a new Tilly on its way Im going to try out, I think it's a HL-388, could be an HL304WX..guy wasnt sure which he sent.


those parts sources you listed in this post are awesome, they have everything, and lots of trick stuff too- the popoff spring is a very critical part of the carburetor. I tried a popoff spring from another carb and the saw would not run, and I had to put the old one spring back in. Each carb is calibrated to application with that spring- bigger saws with more cubes will have a richer spring than smaller saws with small displacement. Keeping the original tune spring is critical, to keep the saw in OEM specs.

great info on this thread, I've referred to it a few times already getting the HL carb on my DB 360 saw ironed out. I'd like to add a few things I've found while doing my own carb.

The adjustment needle screws for high and low metering setting- I found the longer one goes in the "H" hole, the shorter one goes in the "L" hole. "long-high, short-low"- in case you get them mixed up, that's an easy way to remember it.

the different needle valves and seats issue- the new style forked lever with captivated needle valve, uses a shorter needle valve and shallower seat as well- they are not interchangeable with the old style "type 88" kit needles/seats. Putting the old needle valve in the new seat, the seat will stick up too far. The improved seat has a metal seat area, and is not bored through like the old style seat is.

the old style "type 88" seats, to remove the rubber O-ring from the bottom of the seat, remove the seat first, then just push the O-ring out using the needle valve as a push tool- the old style "88" seats are bored all the way through like a tube- this makes cleaning them easy if you need to reuse an old seat, take a pipe cleaner or very fine 1000 grade emery that just polishes the surface inside- and old needle valve can be polished in this manner as well, then the needle/seat slides easily without getting stuck, if that was the original problem

the new shallow seats use a copper o-ring on bottom to seal, the old "type 88" seats use a rubber O-ring that goes inside the bottom of the seat, the O-ring is flat on one side, and has a dimple facing outwards on the other side- all the seals I've seen so far, have the dimple facing outward/downward when installed, and the flat side of seal to the needle valve

I set initial H and L screws per this thread at 1 turn out on L, and 1-1/4 turn out on H, and have not had to touch it since, it runs great at idle and WOT right there.

I noticed that there are (3) governor linkage holes on the left side of my carb, it was in the middle hole originally so I left it there, but it appears that max WOT rpm can be adjusted up or down by moving the governor linkage connection on the carb.

when I removed the intake manifold tube and reed cage, I noticed that the intake/reed gasket was partially covering the port around the edges of the reed ports, and impeding flow somewhat- I cut the gasket with sharp scissors to open that up all around, so it didn't block gas flow- being careful not to cut apart that tiny transfer port of gasket that goes back to the carb- the result was, the engine ran better at WOT and idled better. Watch for correct gasket fit between intake tube and reed block (this has 4 small reed valves)
 
Great post davidbradley360... thank you for adding some more info to the thread. :clap:

Best part about this forum is that there is always more info to learn... even from those of us that have been doing certain things for years... :)

After I had discussed the "88" kits with another well known saw guy here in WA... he told me to yank that needle and seat out of the carb that I had initially used. I will admit there was a noted difference.

So... I wish I could go back and edit the tutorial and reitterate the use of the RK88 kits instead of what I used... which I thought were an "improved" design... maybe the mods will let me do that some day.

Dave? Dan? What say ye? :)

Gary
 

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