Jred 670 champ fuel pickup problems

[jacrawley]

I've written a couple of times about the saw in question. After taking a break from it for a while I've picked it back up.

First off I found this saw in the scrap yard this summer and decided to fix the thing up.

Here's what I "fixed"

Replaced carb with rebuilt/new one
Did pressure test and replaced crank seals.
Put new ring in cause compression was low. Now it seems good.
replaced fuel line/return line/fuel induction(pump) line and tank vent.
replaced cylinder gasket with new ring.
replaced manifold boot cause it had a puncture.

Now I've pulled the bottom of the carb off and verified the fuel float valve is in the right place(according to the manual even with carb body) I've blown in the fuel hose and pressed the diaphram down and it does pass air. The jet screws are both 1 and 1/4 turns outs.

With clear fuel line on this thing bypassing the filter and sitting in a jar full of gas I can see that while pulling the cord it does have some fuel lift but not very much(not enough to pull the fuel to the carb but enough to lift it about an inch into the line) If I fill the hose and hold it vertically it eventually got some fuel into the carb and hit once.

I noticed the fuel pump line nipple on the side of the cylinder was a little loose and I was able to wiggle it out with some pliers. Could this cause the problem? Should I do another pressure test? I'm fairly certain the crank gasket is good. Any other ideas?

thanks
JOseph

 

[PB]

So can you get it to fire? Does it run? Seem like it is flooding? Do you have the diaphragm on the correct side of the gasket? Did you actually test the compression, or just pull it over? Lots of questions, sorry.

 

[Oldsawnut]

I assume you checked the metal filter screen on the other side of the carb just before the float valve. If the diaphram is good and you have a good sealed crankcase it should pump fine. It has to have a leak in something or plugged/pinched/cracked line etc for it not to pump well.

 

[jacrawley]

The saw runs when I put gas straight in the carb. Of course just for a sec until the fuel is consumed.

I have checked the filter screen inside the carb. I did not get to do a compression test after replacing the ring cause my brother wanted his gauge back. I did test it before the ring replacement and it was low and rather easy to turn over. Now it feels much stiffer so I am assuming the compression is in a good range.

I have tested the carb by placing in a cup of water and blowing air in the gas intake. it does not bubble with the float closed. With it open air comes out of both jets. Also no air escapes from the fuel pump nipple.

It seems that I do need to do another crankcase pressure test but wouldn't that have to be a pretty serious leak to cause np fuel to pick up?

thanks for the help, you guys rock