77 LF FUEL PUMP

[S_Kyle]

I have been working on another 440 LF I picked up a few weeks ago. Good spark, good compression etc. Slowly working my way through it. The sled would not draw fuel, so I rebuilt the pump. Put everything back together. Put a new check valve on the line and stuck it in a bottle till I get the tank cleaned. pulled the rope and it did not appear to draw fuel into the line. Dumped a small amount of fuel down the plug holes. Pulled the rope and got the sled to run for a few seconds and it did draw fuel. The fuel then ran out the line. I will have to go back out and check the seal on the line.

But, if it draws fuel wile it runs then the pump must work right? I'm confused right now, maybe a little intoxicated. I don't know.

[harleysportster]

Scott,
You should check the fuel pump by hooking up a regulated source of air set at 5 lbs to the impluse port and valve off. it should not leak down.
Did you check / replace the fuel filter
The ball / check valves have been know to be bad out of the box
Did you clean the carbs and check the float level
The fuel pump should pump fuel within a few pulls of the recoil

[S_Kyle]

Cleaned carbs and did check the float arm.. No filter currently as it is clean fuel, clean line and clean bottle. The check valve was working when I took it out of the package.

I will go check the valve again but. Here's my question the pump was drawing fuel when running, then the pump must be good. It is just a pain to get at and don't want to have to pull it again.

I am confusing myself right now so i will just go back to the garage and play with it some more. Nice thing is the sled got a NOS track shortly before being parked a couple years ago.

[harleysportster]

Scott,
Thinking more about your problem, I would replace the crankseals. If the seal is bad on the side where the impluse port is, it will cause low pump suction during start up. As with any 2 stroke engine with unknown history, always replace the crank seals.

[S_Kyle]

Harley, I plan on doing the crank seals soon. I have been told you can get away with just doing the PTO side seal and leave the motor in the sled. The history on this sled is somewhat known as I got it from my boss and he got it in '78.

Up date. I don't know what my problem was last night, just went out to the garage. Filled the bottle again and this time elevated it, a little gas down the plugs and pulled the rope. It sputtered for a few seconds and then settled into a nice idle.

Next question, I don't have my tech manual with me. What should the idle be on these. Right now I am around 2900-3000, hope to do a quick ripe across the lawn this evening.

[harleysportster]

Harley, I plan on doing the crank seals soon. I have been told you can get away with just doing the PTO side seal and leave the motor in the sled. The history on this sled is somewhat known as I got it from my boss and he got it in '78.

Up date. I don't know what my problem was last night, just went out to the garage. Filled the bottle again and this time elevated it, a little gas down the plugs and pulled the rope. It sputtered for a few seconds and then settled into a nice idle.

Next question, I don't have my tech manual with me. What should the idle be on these. Right now I am around 2900-3000, hope to do a quick ripe across the lawn this evening.

Scott,
You should never just do one seal. The seal behind the flywheel is not that hard to get at. You only have to remove the stator and leave the timing ring alone. You can change both seals without pulling the engine but it is much easier if you do. Pulling the engine only takes about 1 hour.
The reason the engine is running with the bottle elevated is due to gravity.
The manual has the idle at 1800-2200 rpm's.
Pat

[S_Kyle]

Pat, point taken on the seals. I will do them both when I get a clutch puller. It may save me a pile of money this winter, and i will get a chance to clean the belly more thoroughly.

I will get my manuals next time I am at the farm but what is the correct puller for the flywheel, a 2/3 jaw or is there a special one I will have to get?

[harleysportster]

Pat, point taken on the seals. I will do them both when I get a clutch puller. It may save me a pile of money this winter, and i will get a chance to clean the belly more thoroughly.

I will get my manuals next time I am at the farm but what is the correct puller for the flywheel, a 2/3 jaw or is there a special one I will have to get?

Scott,
To remove the flywheel, a typical steering wheel puller is used with the correct size metric bolts that thread into the 3 holes that are predrilled and tapped. They are the holes around the middle of the flywheel, not the holes for mounting the recoil cup.
Pat

[S_Kyle]

Alright I am set to do the seals. Got the seals a puller and a impact, still need the flywheel puller.

I have a brand new clutch puller, should I put some grease or something on the treads before I use it for the first time.

Also what is the best method for taking out the seal. I have been told to use a screw and vice grips, Or a chisel and screwdriver (service manual).


Thanks
Scott

[harleysportster]

Yes, lube the threads of the clutch puller before every use. The seal is in tight, the screw and vise grip method may not pop it out. You can pierce a hole with a small chisel or old screwdriver and pop it out. Be carefull not to nick the crankshaft or the housing bore for the seal.

[ICCSF 108]

Or the bearing cage.

Kenny

[S_Kyle]

, I seem to be having a hard time removing the primary clutch. The puller threads in 3/8 - 1/2 an inch, used to impact on it afterwards and it dosen't seem to want to budge. I didn't try the impact on it very long as I don't want to break it with a decent sized impact. I think I read that if you fill the hole with grease you can use the hydraulic forces to knock it off.