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HD-8 carb tuning and engine timing

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BOBBYR

BOBBYR

Jedi Trainee
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Hi Guys,
Hope everyone is doing alright today.I have a Haynes workshop manual and I have tuned my carbs, following the book, by the letter.I think the method is really good and my 65 3000 is running pretty good. Here comes the big question. Has anyone ever been able to get their engine to idle at 600 RPM's. Every time I try to get it to that RPM , it dies before it gets there.I also would like to get to this RPM for setting the engine timing.Let me know what you guys think. Thanks
Bobby R
 
Bobby, I can get to 800 RPM, not 600 with the engine warm. For timing I get a partner to hold their hands over my carbs and restrict air intake just a little to bring down the RPM's to 600. My engine is stock, rebuilt with 16,000 MI.

John

67 BJ8
 
The only time I get my '65 to idle at 550 RPM is when I pour my extra 110 race gas in the tank and take an afternoon spin. Most of the time its 750-850 RPM.
I tend to blame it on the "Modern pump gas" and the additives placed in them.
One thing I did do recently was to remove the value breather from the 2nd carb.
Based on the advise of an "old-timer" Brit mechanic the rear carb. doesn't run rich now and the 3 rear spark plugs run much cleaner.
 
"value breather from the 2nd carb"?

w
 
My BJ8 will idle (roughly) down to around 300rpm since I installed a Pertronix ignition. Of course, that slow is not practical and my normal idle is around 750rpm so the ignition will run off the generator instead of the battery.
 
WALTER said:
"value breather from the 2nd carb"?

w
Click to expand...
Hi Walter,
Dougie is talking about the hose that goes from the "T" on the valve cover to the air filter. See the red line in the photo. I will guess that a filter has been installed on the "T".
 

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Hi Guys,
Thank you for your responses. My 65 is probably idling most the time at about 900 rpm's.To be honest, I'm pretty happy with the way it idles and I also think the added rpm's help the cooling system with better flow at idle. So far ,I haven't had any problems with cooling, like some of the ones I've read on the forum.Anyway, thanks again for your help.
Bobby R
 
Greg,

Thats exacting the hose I was referring to. I guess it is technically venting from the "rocker" cover. Thanks for clarify this.

Dougie
 
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