Carb problems solved...almost

[Mark_88]

I posted last summer that I couldn't keep the truck running if the choke was opened...was planning on just replacing the carb/intake and was waiting on someone to send me one I could try...well, since that was taking a long time I'd just let it ride...but was talking to a friend of a friend the other day and he offered to have a look at the carb...

Turned out that because the carb sat for three years and there was gas in it when I took it off, the gas turned to turpentine or some other gunk and was plugging up things so bad that the gas would not flow...so he soaked it in a cleaning solvent and brushed out the insides...when I put it on the truck and started it up it fired up after only a couple of cranks and ran for a while without the choke...

Yahooo!...

It still needs a bit of fine tuning but I ran out of time due to other more important matters...but it's one step closer to being ready to go...

 

[skippy]

Thats great!Glad you got it running.

 

[Mark_88]

Thats great!Glad you got it running.

Thanks Skippy....but I'm still not sure I've solved the issue...ran out of gas...lol...will know soon enough though...hopefully it is OK now...but the fact that it starts up and runs without the choke is encouraging...

 

[Mark_88]

Soooo....it runs now...doesn't quite idle smoothly but I think the timing is off slightly...still much better than it was...carb was gunked up with old gas...not a good thing to let them sit without draining them first...

 

[skyy_4life]

hell yea, now just put a timing light on it and u should be good to go.

 

[Mark_88]

Timing light? I've never actually used one to set the timing...maybe that's why I've had problems with it...lol!

 

[Mark_88]

TA~DA~

After a few adjustments it's running now on it's own...revs up...holds higher revs without dropping...and idles almost smoothly...

The head may need a bit of a breaking in period because it has zero hours on it since the rebuild...so far I've had it idling for about half an hour...

May need a bit more tweaking with the fuel mixture but I can't tell...is there a fuel mixture tool that measures if the engine is getting too much fuel? I opened the fuel mixture screw a bit after it was idling in the garage for a few minutes because it smelled too rich...but I've always tuned just by ear and smell alone on a carb...

Any input would be appreciated on this one...

 

[skippy]

Mark,I believe they make exhaust gas analyzers for this,but they cost too much for the home garage.

I use the following method,with engine warmed up and idling,and vacuum guage hooked to intake,turn screw in until engine starts to die,back out screw until the best lean vacuum reading(highest)

Good luck!Skipdawg.

 

[Bryan22]

color of the plugs is the guage for a carburated vehidle. gas turns to kerosene after a while, a good cleaning of the carb and jets is ALWAYS a good idea after letting a carb sitwith gas in it for an extended period of time.

 

[Mark_88]

Mark,I believe they make exhaust gas analyzers for this,but they cost too much for the home garage.

I use the following method,with engine warmed up and idling,and vacuum guage hooked to intake,turn screw in until engine starts to die,back out screw until the best lean vacuum reading(highest)

Good luck!Skipdawg.

Thanks Skipdawg...I do happen to have a vac tester so I'm going to try that later today...

color of the plugs is the guage for a carburated vehidle. gas turns to kerosene after a while, a good cleaning of the carb and jets is ALWAYS a good idea after letting a carb sitwith gas in it for an extended period of time.

That seems to be what solved most of the issues...but now I will need to install a manual choke on it because it won't start without full choke...when I first got the carb/intake it would start even on the coldest days without a choke...and I didn't think anything of it because it worked great for two years...

 

[redgooch]

check the plugs

If the a\f ratio is good the plugs should be a brown ( almost like a chocolate) color. If they are white your engine is running lean & if they are wet its running rich.

 

[Mark_88]

If the a\f ratio is good the plugs should be a brown ( almost like a chocolate) color. If they are white your engine is running lean & if they are wet its running rich.

Thanks, actually that's my next test...

The vac guage helped a bit as the vacuum was lower than it should have been at idle (18-21 in-Hg...whatever that means) so I moved the screw till it leveled out in that range...

Still seems to be a bit of a bump to it when it idles though...not sure if that's just the rebuilt head or something to do with my P&P...I opened it up about 1/8" on both sides (intake and exhaust) and smoothed out the channels all the way to the valve seats (smoothing is apparently OK for carbs but not so good for FI from what I've read)...

 

[pocket-rocket]

Right. If you go too smooth on the intake side, my friend said fuel can fall out of suspension in the air and puddle up instead of staying in a nice mist/vapor form. Grats on getting it running

 

[Bryan22]

since you cleaned it out it's idling rough and giving you a hard time starting? if so, you might need to re-jet it. might be that the size of the jets was closer to right when they were plugged. you'll know when you pull the plugs and check them.

 

[redgooch]

Thanks, actually that's my next test...

The vac guage helped a bit as the vacuum was lower than it should have been at idle (18-21 in-Hg...whatever that means) so I moved the screw till it leveled out in that range...

Still seems to be a bit of a bump to it when it idles though...not sure if that's just the rebuilt head or something to do with my P&P...I opened it up about 1/8" on both sides (intake and exhaust) and smoothed out the channels all the way to the valve seats (smoothing is apparently OK for carbs but not so good for FI from what I've read)...

just some trivia in-Hg means inches of mercury. how much pressure it takes to move a column of mercury one inch. dont know if thats any help but now you know