Tunning dual Weber's

Engine, Transmission and related drivetrain.
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bertvorgon
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Re: Tunning dual Weber's

Post by bertvorgon » 02 Nov 2019 16:11

I would think 10 to 12 would be a good starting point.....been so long I cannot remember what a stock type motor uses, someone else can chime in. Make sure you have some good, fresh fuel in there. Hard to tune around old gas.

That those nuts are so tight is concerning. You should try to find a really good quality wrench that fits snuggly, get it in place, hold it tight and then tap with a hammer as close to the head as possible, this might "shock" them loose.

You are in the zone for valve adjust although the exhaust is a bit tight. but it should run ok. Have you done a compression test? Just to make sure you don not have a slightly burnt valve.

In theory....as you go from the idle to main circuit, it is the progression circuit that helps that transition to the main circuit start up.

It's hard to say at this point till you either exhaust all attempts at adjusting the idle mixture, then next step....would be to change the idle jet...maybe, as a bit of a low float level can delay start up also....which you may have addressed now.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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bertvorgon
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Re: Tunning dual Weber's

Post by bertvorgon » 03 Nov 2019 07:19

"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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RMS
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Re: Tunning dual Weber's

Post by RMS » 03 Nov 2019 19:13

if the locks on the adjusters are real tight and damage cant be overcome by a better open end 14mm wrench, use a 6 point socket by removing the rockers with the aid of a ohv two thumb and hook style valve spring compressor Image. this operation can be a bear as the rocker will not want to pop off the ball with just the spring compressed. you will likely need to remove the lash pad first. use the rope method to support the valve maybe turn the crank back to give a bit of a drop on the valve. then you can do the valve stem seals at the same time. :mrgreen:
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NunoTT
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Re: Tunning dual Weber's

Post by NunoTT » 28 Nov 2019 12:48

Well, I've been away from the Datsun for some time due to university stuff, but today I got a chance to do some things on it.

Last time, I removed the spark plugs, and number one had some oil in it. Today I made a compression test. 130 psi on cylinder 1, 2 and 3. Number 4 was 125 psi. I don't know it the numbers are high or low for a stock L16, but at least they are even.

I also used a timing light to check the timing. It was over 20º. Sadly I had no time to mess with distributor. I'll try to do it tomorrow or next week, depending on how things go in university

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