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Brawr's 1984 KP61 Toyota Starlet Sprint - Discussion


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  • 3 months later...

Vacuum advance has no effect at idle/closed throttle on standard 4K setups.

 

It will start fairly easily with any base timing between 0-18 deg BTDC on standard carbs.

 

Wind your idle mixture screw out a couple more turns as being rich won't hurt it. That should help it start when its cold like that, then wind them in until mixture is correct. Might pay to find someone who is experienced balancing twin carbs, I've heard they can be right bastards.

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Vacuum advance has no effect at idle/closed throttle on standard 4K setups.

 

It will start fairly easily with any base timing between 0-18 deg BTDC on standard carbs.

 

Wind your idle mixture screw out a couple more turns as being rich won't hurt it. That should help it start when its cold like that, then wind them in until mixture is correct. Might pay to find someone who is experienced balancing twin carbs, I've heard they can be right bastards.

 

Good to know about the vacuum advance, thanks! Just went out and made the idles a bit richer as suggested and with a bit of coaxing it started! Sounded rough as hell but at least somewhere to work from. From the look/sound of it i suspect I've got a bit of an air leak around the rearmost manifold bolt (tight spot, silly manifold design, difficult to get a good grip on the bolt) so that's the first place to revisit. Also a few backfires through the carbs and dripped a reasonable amount of fuel out of the 4 barrels when I turned it off, suspect mixture/timing causes for that?

(Optimistic) plan was to try to get it into a state where I can drive it to someone to fine-tune. Hoping to try to learn enough to get it in the right ballpark, then I should have a reasonable enough level of knowledge to at least understand where the experts are coming from...

We'll see!

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are you sure that vac advance has no play at idle/closed throttle position? because generally that's exactly when vac advance comes into play. 

 

i presume youve cranked it enough to fill the carbs with fuel? checked float heights? and is the jetting definatly in the right region to get a start up? 

otherwise sounds like a pretty big air leak leaning it way out. 

 

been there and done all that with the crappy manifold designs when putting bike carbs on my corona, but awesome carbs are well worth the effort and head scratching. 

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Should be able to get that back bolt tight with a 150 mm extension on the socket.

 

Make sure to get that leak fixed before anything else, it will just cause havoc otherwise.

 

Toyota part number 17172-13050 is the best manifold gasket you can use. It is about $27 or something.

 

 

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Thanks for the help guys! Had a bit more of a play today. ajg - is that gasket the triple layer 7k manifold? Picked one of those up a few weeks ago.

 

Managed to Dremel down the outside of the manifold to give enough access to tighten it all down properly, no more air leak. 

 

Starts and idles reasonably comfortably (though starts creeping a bit high, will need to work on that), but still leaking fuel from all 4 venturis. Not managed to get it up to temperature yet, the idea of fuel dripping on to hot exhaust isn't one that I enjoy! Top of my list for that is float adjustment - gave them a bit of a tweak earlier but didn't cure it. Will try a bit more tomorrow. If no improvement... I can't imagine the stock mechanical pump would put out too high a pressure for the carbs could it?! Would I need a regulator?

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Could be the needle that is operated by the float.

 

How long were the carbs sitting?

 

It could pay to get them properly rebuilt by some specialists first. That seems to be what a lot of people do - and then you will know it is done right. Maybe watch/help them do it, would be a good learning opportunity.

 

Only downside is cost.

 

Also yeah that is the triple layer 7k gasket

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  • 2 years later...
  • 3 weeks later...

Thanks for the heads up, but I'm actually running Dynapro calipers - essentially just an updated Dynalite. From the dimensions I've looked at I don't think I'd gain any more clearance from the Dynalites. Rather than being the fault of the brakes, the clearance issue I'm having is due to the silly step in the rear barrel of the equips:

uBIV4Af.jpg

 

Single piece 13s fit fine, annoyingly. 

Thanks for the thought though! :)

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  • 4 weeks later...

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