Carb Jetting
#1
Carb Jetting
OK, 351 & pumper carb, I think I am pretty close on the main jet (130)..... but I am getting poor mileage. My pilot adg is about 1-1.5 out I think. I did a ATV trail with a healthy bunch of throttle twisting & only got 37.5 mpgallon. But this was not a difficult ride.
I was thinking of going to a vehicle smog test garage and have them put it on the machine..... would I get any usefull info out of this or does someone have a better idea.
The bike it running pretty good, but getting a definitive setting short of pulling the engine & finding a dyno is difficult.
351, 33 pumper, 3300 ft elev, stock everything else.
I was thinking of going to a vehicle smog test garage and have them put it on the machine..... would I get any usefull info out of this or does someone have a better idea.
The bike it running pretty good, but getting a definitive setting short of pulling the engine & finding a dyno is difficult.
351, 33 pumper, 3300 ft elev, stock everything else.
#2
Did a little more research, seems like a wide band sensor & display may get some good info to see where the jetting is. I think I'll check into some of the local mech shops to see if they have one available.
I am thinking trying to get to A:F of about 14.7:1 under load.
Anyone ever use this?
I am thinking trying to get to A:F of about 14.7:1 under load.
Anyone ever use this?
#3
I have a dynojet wide band that I use for my 10r. Welding a bung in the exhaust is generally the most difficult issue in order to place the sensor. That should be included with every exhaust now adays in my opinion.
#5
that is true and about the same cost as a smog test
edit: I need to drive 4 hrs for the nearest dyno around here.
#7
OK, got the (Fuel to Air Ratio) wide range sensor installed and headed out to the biggest hill around I-17 south from camp verde. It took a while for the sensor to burn in as I was reading initially around 19-20. After burn in it went down to 13 WOT @ about 70mph-ish. Way to rich. MJ 135 (I thought I had a 130 in it, but not. Boys remember to write these things down as they are important).
Changed MJ to 125 and hit the road again, only I didn't go back to the big hill, the gauge will settle in pretty fast so picked a shorter hills around the house.... reading went to 16.5 ish on WOT in acceloration. The engine was stumbling a little on WOT. It pulled from idle very crisply though and at part throttle at normal speeds the reading were in the 13-15 range.
Therefore, I beleive 130 will be very close. I think I'll take the bike up to 7500ft elev and see how it goes next week though before I do anything, I am thinking of taking it to CO in August, so I may just live with it till then.
Putting the bike away I found the part in the picture... anyone know what it is? It is suppose to snap together around a cable/hose/wire? and then it may be a grommet? It may be off my bmw 650, if it is.. now I am worried.
The bike was dead when I tried to start it, had to bump start it. I removed the battery and topped off the water in it. I think I put too much in as after I started it, water was leaking out of it as it was boiling over. Oh well, it was really dry from the heat around here.
Changed MJ to 125 and hit the road again, only I didn't go back to the big hill, the gauge will settle in pretty fast so picked a shorter hills around the house.... reading went to 16.5 ish on WOT in acceloration. The engine was stumbling a little on WOT. It pulled from idle very crisply though and at part throttle at normal speeds the reading were in the 13-15 range.
Therefore, I beleive 130 will be very close. I think I'll take the bike up to 7500ft elev and see how it goes next week though before I do anything, I am thinking of taking it to CO in August, so I may just live with it till then.
Putting the bike away I found the part in the picture... anyone know what it is? It is suppose to snap together around a cable/hose/wire? and then it may be a grommet? It may be off my bmw 650, if it is.. now I am worried.
The bike was dead when I tried to start it, had to bump start it. I removed the battery and topped off the water in it. I think I put too much in as after I started it, water was leaking out of it as it was boiling over. Oh well, it was really dry from the heat around here.
Last edited by durielk; 03-30-2012 at 03:13 AM.
#9
jhoffy, I see the part you are holding up, but not very clear. The part I have when you get it hooked together has a smooth exterior cylinder shape like it is a grommet for a cable that passes through it, then it goes in a hole.
That is near the rear of the bike, where I was messing with it, but where does that thing you are holding up go?
That is near the rear of the bike, where I was messing with it, but where does that thing you are holding up go?
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