Tillotson HL Carb Rebuild + Questions

[295 tramp]

Hello
Today I decided to rebuild my Tillotson HL 147B carb that goes on a Stihl 07.
I bought a Winderosa Brand universal aftermarket rebuild kit for HL carbs.


At first looking at the package, it looked to have everything to do the job.
Once I opened and organized the parts I disassembled the carb.
I started to see there was differences in the old verses new.
I know there's going to be differences between OEM verses Aftermarket
The diaphragm for the metering lever and gasket were the same.
The diaphragm with what I call the flappers were different.
The old ones use the rubber and the gasket.
the new has to use a plastic flapper diaphragm a rubber diaphragm to block off
the large round hole and a gasket.
Question 1, can I use the new ones with the extra piece.

Next I pulled the metering lever, needle and seat.
I noticed to pull the pin for the lever has what looks like a sealer or Loctite on the screw.

The old lever has no fork for the needle and the needle doesn't have the slot cut in the top to connect to the lever.
The new lever and needle is like what is the normal setup for most carbs

Question 2 can this new setup be used ?
I'm no carb engineer, My way of thinking is that the new setup would open the needle and keep it from sticking.
As the old style is either pressure opened or gravity opened.
Thanks for any help or advice offered.

 

[Chainsaw Jim]

It looks pretty clean. Was it that clean when you took it apart? If so then don't worry about the needle and just replace the metering diaphragm. If the pump diaphragm flaps aren't warped then the old one may be ok to reuse.

 

[295 tramp]

I have had this carb apart many times. The old rubber flapper I can reuse.
I'm just wondering how the old needle opens?
Is it pressure or gravity since the metering lever and needle are not connected?

 

[cmsmoke]

The answer is both. Fuel is pumped under pressure coming in from the top of the needle. When the diaphragm lifts and the lever is moved away from the bottom of the needle, gravity would also come into play. With the new style that grabs the needle there would be less chance of sticking with the mechanical connection. You can use the new set up provided the needle length is correct. Follow the service procedure to check the height. There is a you tube video on rebuilding a HL and do a search here on the forum. A member named Gary has a nice write up on Tillotsons.

 

[295 tramp]

Thanks CMSMOKE that's what I thought.

 

[cmsmoke]

This is the thread, I don't know how to post the link.
Tillotson HL Carb Rebuild w/pics
Discussion in 'Chainsaw' started by GASoline71, Mar 15, 2008.

 

[295 tramp]

Here is the link. Good Information.
Thanks
http://www.arboristsite.com/community/threads/tillotson-hl-carb-rebuild-w-pics.64450/

 

[leeha]

Not to throw stones but next time you need to rebuild a carb buy
an oem original kit. I have had issues with the two aftermarket kits
i used years ago. There are several kits for the HL series carbs. The
most common is the RK-88 kit. Hard to tell what in your kit will work
without having it in my hands.


Lee