greg g Posted April 25, 2021 Report Share Posted April 25, 2021 Did you pull a vacuum test? Link to comment Share on other sites More sharing options...
Los_Control Posted April 25, 2021 Report Share Posted April 25, 2021 My 2 cents, if adding a little choke helps. Seems like it is getting extra air from somewhere ... All the choke is doing is blocking the air volume introduced into the engine. Naturally you would want to adjust the air intake with carb adjustments & not the choke. You just need to find where the extra air is getting into the fuel system. Of course it works pretty good most of the time, not going to be easy to duplicate and reproduce in the driveway. I am sure others have already suggested some carb cleaner spray around the throttle shaft, base of carb ... all ports of air entry ... and the intake manifold. Possible the intake gasket is leaking & sucking air? Link to comment Share on other sites More sharing options...
Sam Buchanan Posted April 25, 2021 Author Report Share Posted April 25, 2021 I appreciate all the comments and suggestions. However, it is obvious that some commenters have not read all the thread and are not familiar with the history of my car even though it has been well documented on this forum the past two years. In regard to this suggestion: How about fuel delivery? At these speeds your engine is thirsty. Could be carb float height, clogged passages, jets. Fuel line, Tank. Pump, filter, swollen rubber hose. If carb is ok, try adding an electric fuel pump as a test. Not any but one with max pressure 4.5 PSI like Airtex E8902 Response: Float has been carefully checked and set slightly below book spec. Within the past two years I have installed new fuel tank, lines, filters, and electric pump (mechanical pump removed). Carb was disassembled and cleaned. Here is where the restricted fuel flow diagnosis is flawed. The engine runs great under full throttle and heavy load. I have stated this several times in this thread but fuel starvation continues to be offered as a diagnosis. And yes, the intake gasket was replaced last year and I have carefully torqued the fasteners. What kind of "vacuum test" is being suggested? I've had a vacuum gauge hooked up to verify general engine health and all looked good. The hesitation isn't a significant drivability issue, I'm just curious about it since the engine is flawless in all other regards. Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted April 25, 2021 Report Share Posted April 25, 2021 per your description I would have to ask what is your total advance.....first is the mechanical and is it in the ball park....now add you vacuum for max total and see if you may be advancing a bit too far and leaning out too much....you will need a better built timing light with the dial to check timing advance....or at least a timing tape Link to comment Share on other sites More sharing options...
Los_Control Posted April 25, 2021 Report Share Posted April 25, 2021 We all love puzzles. Fact is, these engines are very simple ... Like a lawn mower engine. Just not to much to them. While we are all rooting for you and hoping you figure it out .... Really is a lawn mower engine with a few extra cylinders. Just saying do not get upset at us for offering advice to fix your 6cyl flathead lawnmower ... There is only so many options to fix it. That is your problem to fix, we only have suggestions. .... Yes it really is a simple flathead & basic carb issues to fix ... is a learning curve. Link to comment Share on other sites More sharing options...
Los_Control Posted April 25, 2021 Report Share Posted April 25, 2021 Can we all imagine that my briggs & stoner motor does not accelerate as fast as I want it to? @Sam Buchanan send me a address & I will send you a fruit cake at Christmas time. We all love you. What you are talking about is a tuning issue that possibly can only be fixed from a person in presence. I am the total idiot that thinks @Sam Buchanancan learn & fix the issue, then share it with others. Either way you have a fruitcake coming. Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted April 25, 2021 Report Share Posted April 25, 2021 Los, as a member of the forum and as one member to another, we can only volunteer suggestions based on the data provided...we neither are in the position to look over his shoulder and or direct the task be it testing or repairs. If you think a response falls on deaf ear, turn the blind eye and move on to another thread it is not worth the worry. Link to comment Share on other sites More sharing options...
Los_Control Posted April 26, 2021 Report Share Posted April 26, 2021 I honestly think it is a non issue. I also think this motor was made for 40 or 50 years? Can you imagine this engine in the Are we talking about engines built in this time period? I am saying to not start a **** show on why your car not perform ... Just fix it!. Link to comment Share on other sites More sharing options...
Los_Control Posted April 26, 2021 Report Share Posted April 26, 2021 @Plymouthy Adams My only issue is to talk about some serious issues & talking about the current issues @Sam Buchanan seriously, if you can use that engine and idle it down. There is no reason to idle it lower. But if you are on a page it really does not matter what you do not master. I have to laugh at what is shown. Link to comment Share on other sites More sharing options...
Sam Buchanan Posted April 26, 2021 Author Report Share Posted April 26, 2021 (edited) I can assure you there are no deaf ears in my corner of the P15 community. The only thing I was kinda speaking to is suggestions that definitely do not address the problem I described because of lack of reading the description of symptoms I have described numerous times in this thread. But that is an insignificant issue compared to most problems we face each day (in my case the recent loss of my housemate of 45 years....who loved riding shotgun in the '48). But I've seen it said that many "carb" problems are in fact ignition problems. I'm going to give the vacuum advance a hard look and also make sure the breaker plate is moving freely with no binding. Another thought I've had is carb ice. The hesitation occurs with the throttle barely open, prime conditions for ice. I have the heat riser blocked off, don't know if this might be a factor. I do appreciate the comments, most of them are providing ideas to explore. I want to emphasize again how minor this issue is, just just enough to notice under the right conditions (and prompt "Why is it doing that?") but not significant enough to cause drivability problems. Edited April 26, 2021 by Sam Buchanan Link to comment Share on other sites More sharing options...
adminstrator_p15d24ph Posted April 26, 2021 Report Share Posted April 26, 2021 Locking, useful suggestions seem to have ended. Link to comment Share on other sites More sharing options...
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