Reviving my P18 after PO gave up!

[Hook47]

Thank you Gents! That gives me places to start. I may try spraying the old carb cleaner trick to see if I hear the idle change. The vacuum system is extremely simple (the wipers aren't hooked up and it's plugged). I can't seem to find where they would hook up, as I suspected that could be a place where I'm leaking vacuum. 

 

Throttle plate looks good and choke is working A OK. I actually felt brave and went on a 10 mile test drive today. She did great, but still idled high at the end.  She at least got a splash of new gas at the station! 

 

The engine sounds like it's running on all six, very smooth and strong now, no misses. It's still a little "clattery" as the wife described it, but having never heard another Deluxe run I feel like the valve noise is probably normal for the Flahead six? I've got a Dodge M37 with a flathead and it has a similar sound (I don't know how similar the engines are mechanically).

 

Aside from the high idle, the only other tuning issue I have is a bit of a pop from the exhaust at idle. Not a back fire, but still sounds like she isn't quite dialed in. 

 

I appreciate all the help guys, so close to having this car where I want it! 

[Hook47]

OK fellas, rooting around the carborator has revealed my issue. Not sure this will be an easy fix, though! 

 

The throttle linkage attachment point is very loose. It had a lot of play in it. The bracket where the idle adjustment screw is located (where the throttle linkage connects) is loose in the vertical Axis, meaning it has a lot of up and down play like it is worn out. When I move the bracket, the idle changes significantly. 

 

What are my options here? I'm not finding aftermarket parts for this carb and I got a feeling I'm not going to. 

[keithb7]

Options I can think of include finding spare used carbs and swapping out worn parts.  You may also be able to meet up with a friend  who can machine bushings and enlarge bores in the carb to install them. This would tighten-up gaps and stop air leaks. 

You could also consider buying a new carb. I’m not informed in this area. Sounds like you can buy carbs that will fit and work. I have. No idea about quality and support with them. Could be done if you know needed air-flow and jetting. 

[Sam Buchanan]

You might be interested in this carb:

 

https://newcarburetors.com/carbs/y200.html

 

 

[Hook47]

Well, I found the answer to the high idle. The answer is- I am an idiot! 

 

What I thought was a failed rod for the throttle plate was much simpler. The bracket which attaches to the rod, and the rest of the throttle linkage was loose, not the actual throttle plate! Under some grime I found a friction screw that allowed me to adjust it and lock it in place... 

 

I've got her idling better now, and responding to the enrichener screw! 

 

I still can't help but wonder if I've got it running right. It sure feels like it's hitting on all 6, but as mentioned above there is some valvetrain noise (not scary amounts, but noticeable. Is it normal for this motor? Need to start the M37 which has been dormant a few months!) And there is that occasional pop in the exhaust. 

 

While my current carb is OK, I'm intrigued by the carb posted by Sam! Anyone have any experience with this carb? Sam, would you say it's worth a swap? If I don't use it for the P18 I've got another dozen motors around it would mount up to! 

[Dave72dt]

You can use a timing light to check for consistent spark watching the flashes as you apply the lead to each plug wire.  Checking the valve lash won't hurt and should be part of a tune on an unknown engine.

[Sam Buchanan]

2 hours ago, Hook47 said:

While my current carb is OK, I'm intrigued by the carb posted by Sam! Anyone have any experience with this carb? Sam, would you say it's worth a swap? If I don't use it for the P18 I've got another dozen motors around it would mount up to! 

 

I don't have personal experience with the carb but I think I recall someone on the forum a year or so ago mentioning they have used one successfully. Maybe they will see this and respond.