Electric choke for Weber carb? '94 Echelon

[Woodski]

@Michigan boarder - Without a feel for your boat and not able to do a spark plug read (that certainly ages me!), the safe way is to go with the previous setup.  I would go with old and then consider doing some changes down the road.  You need to transfer the accel pump spring over.  The jets are close to what I have, basically a step leaner on primary and a couple on secondary, you might want to try a slightly richer secondary jet that may give you a bit at top end.  My discharge nozzle is a step up at .045" and that helped.  Also closest hole on accel pump to get max stroke.  Of course, the cam makes a difference on what the engine likes so makes changes slowly.  BTW - nice setup for carb work and great teaching project.

[Michigan boarder]

2 hours ago, Woodski said:

@Michigan boarder - Without a feel for your boat and not able to do a spark plug read (that certainly ages me!), the safe way is to go with the previous setup.  I would go with old and then consider doing some changes down the road.  You need to transfer the accel pump spring over.  The jets are close to what I have, basically a step leaner on primary and a couple on secondary, you might want to try a slightly richer secondary jet that may give you a bit at top end.  My discharge nozzle is a step up at .045" and that helped.  Also closest hole on accel pump to get max stroke.  Of course, the cam makes a difference on what the engine likes so makes changes slowly.  BTW - nice setup for carb work and great teaching project.

I like the way it runs all around, from idle thru WOT.  However, if I can get a little more top end, that would be good because I plan on hosting some barefooting clinics with our ski team this summer and will likely pull 4 to 6 footers at a time (step offs).  Do you think I should move the secondary from .098 to .100?  I am going to pull a couple of spark plugs today and see what they look like.  

[Michigan boarder]

Our of curiosity I removed the cover from the discharge nozzle.  On my old carb there is a rectanglular brass stock inside and on the new carb there is a spring inside.  The square stock is what should be there, correct?  It doesn't have any numbers on it.

Old carb:

New carb:

Removed and compared:

 

[Woodski]

@Michigan boarder - yes I believe you are correct on the previous post.  There should be some sort of check / ball & weight under the discharge nozzle.

Worth a try although it is about airflow, but if the mixture is too lean under load it may not pull as well as it could.  For reference and of course a bit hard to compare, I was surprised at how much I needed to richen the mixture due to what I think is the stroke change (cam profile has a lot to do with it also) to keep it from being too lean.

Also, it looks like that is the original spark arrestor, I changed mine as doing an A-B comparison the original one was 200 RPM short compared to open.  I made one that has more surface area to allow enough airflow.  That was before I bumped up to 383.  I would certainly try that.

Edited April 26, 2020 by Woodski

[Michigan boarder]

I finally got together with the boys and wrapped it up.  We are sticking with the old parts, and simply swapped everything over.  I will start experimenting with the air flow once we get it in the water, I forgot about you mentioning that a while ago.

How exactly does this choke work?  I have not been able to run the boat yet (need oil, install new impeller, etc.).  I installed the carb, and adjusted the choke so that it is closed within a credit card when cold.  When I turn the key to run (not start), should I hear a click or anything from the choke assembly?  It doesn't do anything, and I kind of was expecting it to.  I grounded to the main fuse breaker bracket and took the 12v+ from the coil.  I have 10.8v at the choke.  As the engine warms up it will simply open up?  I haven't touched one of these in so long.

 

[Woodski]

@Michigan boarder - Traditional chokes use a bimetallic spring that winds or unwinds as the temperature changes with the unit stuck down in the manifold within proximity to a heat source, the electric version simply does the same thing voltage signal telling the carb what the temperature is.  What you will do is twist the black cap to calibrate to how you like the choke to work, it might be a bit rich or lean depending on the signal and actual temperature of the day.  As an example, I have to set mine a couple of times a year, as it will be too lean in summer and a bit rich in cooler weather at a given setting.  I basically go one notch to the rich side or one notch to the lean side to dial it in.  You loosen the three little screws and rotate the cap to where you want based on the notches on the housing.  A little trial and error after the initial setting which should be close.

[Michigan boarder]

3 hours ago, Woodski said:

@Michigan boarder - Traditional chokes use a bimetallic spring that winds or unwinds as the temperature changes with the unit stuck down in the manifold within proximity to a heat source, the electric version simply does the same thing voltage signal telling the carb what the temperature is.  What you will do is twist the black cap to calibrate to how you like the choke to work, it might be a bit rich or lean depending on the signal and actual temperature of the day.  As an example, I have to set mine a couple of times a year, as it will be too lean in summer and a bit rich in cooler weather at a given setting.  I basically go one notch to the rich side or one notch to the lean side to dial it in.  You loosen the three little screws and rotate the cap to where you want based on the notches on the housing.  A little trial and error after the initial setting which should be close.

Got it, I did all of that, watching the butterfly move as I turned the cap back and forth.  I mostly didn't understand how it opened after heating up.  I did some reading and now realize that the bimetallic spring is heated by the voltage.  So it's not really a matter of engine/carb temperature, but a timed value.  That is why yours needs adjustment on initial starts seasonally, because it is not reading the carb temperature, it is timing it to open.  So on a 30 degree warmer morning, the engine warms up faster, so it requires less time to be choked, and the way to fix that is to unwind the spring a little looser.

I also read on several places that I should not be getting voltage from the coil because it is not a full 12 volts, which is supported in my reading above showing 10.8v coming from the coil.  So the next question is where should I pick up +12v from?  My thought is the alternator, but I could also go to that main breaker above the fuel/water separator.  What do you think?

And it's snowing outside right now.  Low tonight 28.

[Woodski]

I don't recall where the wire is coming from, I'll have to look but I kind of recall it heads back to the coil and gets it there.  The ground simply attaches to the old intake manifold right below the choke.  Just a comment on the choke operation to help your calibration process, its not really the opening timing that creates the need for adjusting, it is the initial setting point thus the closing spring pressure that sets the choke for start up.  The warm up phase goes okay, its the initial start that is either too rich or too lean.  Once the manifold warms up just a bit, the fuel atomizes better and engine runs fine.  It is pretty obvious when you need to adjust, you'll be good, get black smoke and the obvious rich running or it will sputter and have trouble idling smoothly.  You certainly experienced that with as I recall using a cable choke.  In my experience, it tends to simply be setting the choke one notch to either side of neutral (the longer mark on the housing).  Good luck.

[Michigan boarder]

Current problem, the boat cranks but will not start.  I also changed the cap and rotor, and have verified that the rotor is all the way down and the cap is on properly, and the wires are correct.  I get occasional backfires, some really loud, thru the exhaust.  What am i missing?  I pulled spark plug #3 and it was bone dry.  I pulled spark plug #7 and it was soaked, tilted it upside down and 2 drops of gas came out.  I have verified that the accelerator pump is squirting gas in when I pump the throttle.  It has not even tried to start, it just cranks and occasionally backfires.

Any suggestions?

[oldjeep]

54 minutes ago, Michigan boarder said:

Current problem, the boat cranks but will not start.  I also changed the cap and rotor, and have verified that the rotor is all the way down and the cap is on properly, and the wires are correct.  I get occasional backfires, some really loud, thru the exhaust.  What am i missing?  I pulled spark plug #3 and it was bone dry.  I pulled spark plug #7 and it was soaked, tilted it upside down and 2 drops of gas came out.  I have verified that the accelerator pump is squirting gas in when I pump the throttle.  It has not even tried to start, it just cranks and occasionally backfires.

Any suggestions?

Only suggestion is to verify the plug wires again.

[Michigan boarder]

I verified the order.  The plugs were numbered when we first installed the engine in 2015.  Traced each one to the cylinder, they are correct.  They are correct on the distributor too, and all are in tightly.  I removed the cap to see if anything looked wrong inside, and there is evidence of the rotor firing on the cap, small dark marks (brand new cap).  Reinstalled.  Rotor is in the exact same orientation as it was removed, only goes on one way and I made sure it was correct and low enough.  Still no luck with it starting.  I think there is something wrong with this carburetor.

Uploading of pics is failing.  It's a great day.

[justgary]

It might be worth taking the carb apart to verify that you used the correct gaskets.  A blocked passage could cause a lot of trouble. 

[Michigan boarder]

On 5/21/2020 at 3:49 PM, justgary said:

It might be worth taking the carb apart to verify that you used the correct gaskets.  A blocked passage could cause a lot of trouble. 

We never changed any gaskets, just the metering rods and jets and accelerator pump and spring.  Something else was up.  

[Michigan boarder]

So I said screw it and ordered a new carb, another Weber, same as what I had before except with an electric choke, which is been the goal all along.  I discussed the engine improvements, the hp & torque ratings, etc. and recommended the jetting to them.  I asked them to document the build when they put the carb together.  I just got the carb today and they have the following listed for jetting:

Carb I got today:

Primary jets .101, metering rods 6842, secondary jets .077

Carb I've been running since rebuild:

Primary jets .107, metering rods 6542, secondary jets .098

Did I just go backwards in performance, or is it the opposite of what I'm thinking?  I feel like I should just swap back to my old jetting.  Also I swear I posted other stuff after @justgary's comment on 5/21 but it's now missing.

Edited June 2, 2020 by Michigan boarder

[Michigan boarder]

I've been scouring the internet and have another finding.  The Weber carb that I've been running is a 9772 model, which is what is stock on a lot of 454 engines, with the .107 and .098 as the stock jetting, and is a 750cfm carb. Same with the accelerator spring, my old carb had the larger one that I found recommended as an improvement to use for guys that want to eliminate hesitation on their WOT transition in 454ci engines, which actually is a stock spring on the 850cfm carb.   Which now makes more sense, based on how my carb performed on the dyno machine compared to another 650cfm, a holley 750, and a Quick Fuel Technologies 850.

The Weber carb that comes on the stock 265hp 350ci Echelon engine is supposed to be a 600cfm carb.  So I think what they did was go backwards on this new carb build to match my 388ci, which is 15% less cubic inches than the 454.  Either way, I am going to swap out the rods, jets, check the accel spring and swap if necessary, and use the 

[Michigan boarder]

So I went ahead and swapped my jets, metering rods, and accelerator pump over to the new carb.  In the process I discovered that something was not rotating right in the old one, not sure what it is but something is definitely wrong.  And the choke on the old one is not working, which was the whole point of this.  I also discovered that the carb company had 4 different jets installed.  They said they had .101 primary and .077 secondary but what was actually in the carb was .113 and .101 primary and .098 and .077 secondary.  Is there a reason to do that?  Regardless, my .107 primaries and .098 secondaries are now installed with my 6542 rods.  

Then after everything is connected, and tightening the front bolts, one got looser.  And looser.  And I pulled on it and it came out with 3 threads attached to it from the Performer intake.  So frustrating, I definitely did not heave on it but clearly at some point during these carb swaps and installs I clearly over did it.  Can I just JBWeld the bolt back in?  All it has to do is hold the carb down and prevent an air leak.  Or do I need to pull the carb and intake back off and have it fixed some other way?  Or is there a way to fix it without removing it and resorting to epoxy?

[justgary]

Depending on the insert you use and how you do the job, it may be possible to drill and tap for a thread insert without removing the manifold. 

I'm sure you are ready for the troubles with this to be behind you. 

[Woodski]

Your recent posts just popped up for me so you might be right that something odd happened.

As for your dilemma, the no start and backfire sound a lot like a timing issue so make sure that is good.  Offset jets on primary and secondary circuits are done in oval track racing for g forces.  

Best fix for threads would be a heli coil.

Edited June 3, 2020 by Woodski

[Michigan boarder]

The new carb is on (epoxy with a straw into the hole, then inserted the stud) and it does the same thing.  I've traced the plug wires several times, all is fine.  After cranking it and getting the same results (never tries to start, just pops from the exhaust occasionally) turned the key off, then back on and checked the voltage from the coil.  With the key on it has zero volts.  What is the next upstream thing to test?

Also, separately but possibly related, the popular opinion on Eddy and Holley sites say never to go to the coil for a choke wire, and to use the S terminal on the alternator.  I connected the choke wire (the red one in the pic) but my S terminal puts out 12v all the time, without the key on.  And the choke coil was getting pretty hot.  Do I have a bad alternator too, that is allowing a constant voltage drain?  That would explain me getting 2 years max out of a battery.

Edited June 5, 2020 by Michigan boarder

[Michigan boarder]

Update.  This time, with the key on (and buzzer going off), not cranking the engine, I held the meter to the coil and the voltage was going all over the place, from zero to +4 back to zero up to +7, etc.  And that is with me holding the meter solid and tight to the two posts, with a very good connection.

Also I pulled the cannon plug and it is clean, and has had a clamp on it so it's tight.  Reinstalled.

All connections are tight and clean under the helm at the ignition switch.

 

Edited June 5, 2020 by Michigan boarder

[justgary]

It's not a bad idea to gently spread the pins on the cannon plug to make sure they make contact during vibration. 

[Michigan boarder]

1 hour ago, justgary said:

It's not a bad idea to gently spread the pins on the cannon plug to make sure they make contact during vibration. 

OK, I'll try that tomorrow.  I'm at a loss.  I'd hate to take this somewhere for repair.

[Woodski]

Try disconnecting the choke and doing it manually to see if it will start and run

Edited June 5, 2020 by Woodski

[Michigan boarder]

1 hour ago, Woodski said:

Try disconnecting the choke and doing it manually to see if it will start and run

Already tried that, no change.  I am going to start back to TDC on the dist again.  

[Woodski]

Good plan, run through the firing order although a no fire as opposed to a miss implies the rotor is aimed at the wrong cylinder rather than a couple of wires crossed.  Also, when aligning the distributor while having at TDC it can be on the wrong stroke so the distributor will show 180 degrees out.  An easy way to look at that is to pull a valve cover and look at valve position.  I am sure you are fully aware of that but sometimes easy to overlook (gives one that Homer Simpson moment:-)

Edited June 6, 2020 by Woodski