Engine woes

kwduffy · #1 09-02-2010, 09:22 PM

So the 147 I picked up last week wasn't running quite right when I got it. It would run, but sputtery and was back firing a bit, only way It starts to smooth out, is with it at half choke, and it has a charging issue somewhere. So went through it today and gave it a once over with some new parts and stuff.

Good part, it has a replacement 14hp engine, with a STD piston and you can still see the crosshatching on the cylinder walls, S/G tested good when I spun it up and grounded the F terminal.

Bad news, it has a Walboro carb, which I cleaned, put in new gaskets, and a new needle. It is still running the same after worked on the carb, decarbonized the head, gave it a new head gasket, and put in a new plug. Still need to locate the charging issue which I am not really concerned with right now (most likely wiring, it looks like a rats nest of original and "replacement" wiring)

It will start up, but will only run at half throttle or more, runs rough, backfires a bit, and will only start to sound normal at half choke.

Any ideas?

TEET · #2 09-02-2010, 09:42 PM

This might sound too simple, but did you verify fuel flow? I had a similar problem with my 127, and it had a piece of junk in the fuel line...It ran ok until it was throttled up. It looked like it was trickling pretty good when I disconnected the hose, but it wasn't enough flow once the throttle was set higher.....just something else to check.

Jeff (teet)

kwduffy · #3 09-02-2010, 09:46 PM

Yeah, fuel flow is good, forgot to turn the shut off valve to the off position when I took the tank off to do the head gasket haha.

TEET · #4 09-02-2010, 10:35 PM

Hmmmm..is the timing set properly?

Jeff (teet)

kwduffy · #5 09-02-2010, 10:41 PM

Thats kind of what I am leaning towards, never dealt with timing before so going to have to wait till tomorrow after I can catch up on my service manual reading tonight

TEET · #6 09-02-2010, 11:11 PM

Check out Matt G's Static Timing procedure too...he did a nice write up on it... http://mgonitzke.net16.net/tools/static_timing.pdf

Good luck,

Jeff (teet)

kwduffy · #7 09-03-2010, 12:20 AM

So went out to take a look since I already had the points cover off from earlier testing and didn't put it back on. Got my multimeter out, got it to just break continuity and then went to go look in the sight hole...and its not there, I cant find it for the life of me. Wondering if it could have been moved else where since this is not the original motor

Methos · #8 09-03-2010, 03:24 AM

Quote:

Originally Posted by kwduffy

So went out to take a look since I already had the points cover off from earlier testing and didn't put it back on. Got my multimeter out, got it to just break continuity and then went to go look in the sight hole...and its not there, I cant find it for the life of me. Wondering if it could have been moved else where since this is not the original motor

Its stamped pretty lightly but it's there. Once you find it use some "white out" so you can find it again easier.

Matt's guide is awesome!

ljones · #9 09-03-2010, 08:10 AM

I have a "rats nest" of original and replacment wiering on my 122 at some point in its life the throttel cabel touched the terminals on the solinoid and cooked abunch of stuff.

I used Matts static timing on both of my cubs and they ran alot better after I got them timed.

Hubman · #10 09-03-2010, 08:29 AM

KWDuffy , It depends on what model you have . I have a 123 it is not located the same place in Matt's awesome tutorial .

While sitting on tractor mine is on the right side on the blower housing by S/G. There also is a little button covering hole . In picture sitting on wires is the button removed from hole. I believe Model 71 has sight hole location similar to Matt's tutorial . Models 102 ,122, 123 . have on right side by blower housing. Most likely other model cubs have this similar location.