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Author: Subject: Where to start first with Carbs
RobBrown

posted on 12/8/12 at 12:40 PM Reply With Quote
Where to start first with Carbs

Hi All

It's been a while (too long) but I was motivated yesterday to dust off the car and make sure everything still worked, and swap my dellortos over to the Bike carbs that I've been meaning to fit.

So now I'm after some practical advice.

I made sure the engine started and ran (on the dellortos) before doing anything, so whipped them off and mounted the R1 carbs (from fleabay), onto the car.

I connected the fuel directly from my mechanical pinto pump, directly to the pipe on the underside of the carbs.

But no joy in starting. A little bit of fuel was coming out of the black pipe on top (between 3 and 4)

What do I address first (bearing in mind I know nothing about these carbs)?

Should I be drilling out the main jet to 1.6mm first, or is there something more fundamental first?

Should I expect these to start, if they came off a running engine?

Once I know things are running, if not a bit lumpy I'll get them to a RR.

Thanks
Rob

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maccmike

posted on 12/8/12 at 01:46 PM Reply With Quote
Id have the bike pump fitted for one.
I assume the carbs have been sat for a bit?
Take carbs off
Split them into 4
Remove and clean with brake cleaner/petrol and an airline;
float bowls
floats (no cracks or leaks)
all the jets

carb tops
diagrams for splits

check the orings on the joining pipes for splits/damage.

clean or renew inline fuel filter.

Probably put fresh fuel in too if its been sat.

Check and re set floats if required.

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RobBrown

posted on 12/8/12 at 02:15 PM Reply With Quote
After a bit of googling, went out and changed the needle ride height.

Moved the circlip from the top to the bottom.

Started first time

maccmike - thanks for the response. These came pretty clean, and although have been sat around, had been in bubble wrap etc, so confident that they would be clean enough to run. I'd also read (although you can get Google to prove anything), that if the Pinto was a Carb origianllly then the mechanical pump should be OK, just with a regulator in. I don't know - I'll see how this goes for now - those bike pumps are expensive!

I checked the diaphams when changing the needle height

It runs OK - spits when I increase the RPM - I will move the circlip back up gradually - Any ideas what the normal setting is?

Any know what the spit at higher revs is due to?

Big smile - now motivated to complete this and get it running.

I'll take a video shortly

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JeffHs

posted on 12/8/12 at 02:25 PM Reply With Quote
I'm very interested in your progress. I've just about given up trying to get mine to run sweetly on DCOE 40s (they're old and have been hacked about in the past). So decided I needed to switch to bike carbs. Keep us posted.
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scoop

posted on 12/8/12 at 03:01 PM Reply With Quote
I'm pretty sure will need a bike pump. Save loads of hassle in the long run as they run quite a low pressure and are usually the interrupter type so won't flood the carbs. I would drill the main jet to 1.6mm. How many rings have you got on the needles? Have you blocked the air intake holes up? There are loads of threads on here about this.
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scoop

posted on 12/8/12 at 03:08 PM Reply With Quote
It's all flooding back to me now.
Are there idle control screws on R1's? If so screw them in until they are gently pinched up and mark the screw and the carb body and then turn them out two full turns. Usually on bike carbs one is set on the air flow and you will need to balance the others to it.

[Edited on 12/8/12 by scoop]

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RobBrown

posted on 12/8/12 at 04:02 PM Reply With Quote
5 ring settings

Was originally set on top setting - Too lean I suspect, so I moved to bottom - started straight away. Moved to middle spat heavily

now on 2nd ring from bottom (still spits)
youtubelink

I still think this is too lean. Would adjusting the idle control screw fix this?

The idle control screw is a bugger to get to when fitted to the car! I'm conscious of them getting out of sync.

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scoop

posted on 12/8/12 at 04:10 PM Reply With Quote
Well, I would say you need to start with the idle and flow.
I was going to suggest one up from the bottom on the needle.
The easiest way to get to the idle screws is either from underneath with a log screwdriver or just release the four clps that hold them to the manifold and flip them over. Should be one for each carb?

[Edited on 12/8/12 by scoop]

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scoop

posted on 12/8/12 at 04:12 PM Reply With Quote
Long screwdriver! Bloody iPads!
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RobBrown

posted on 12/8/12 at 05:52 PM Reply With Quote
Just discovered cracked engine block, leaking water. Will have to sort out carbs later

More cost, more delay.

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scoop

posted on 12/8/12 at 06:50 PM Reply With Quote
Oh Christ. What a 205 block? I thought they were bomb proof?
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RobBrown

posted on 12/8/12 at 08:02 PM Reply With Quote
quote:
Originally posted by scoop
Oh Christ. What a 205 block? I thought they were bomb proof?


Yep. just to the right of where the 205 is stamped as well, just to rub it in.

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rusty nuts

posted on 12/8/12 at 08:32 PM Reply With Quote
Lack of antifreeze?
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RobBrown

posted on 12/8/12 at 08:44 PM Reply With Quote
The mix would have been very week as I replaced a Core plug earlier in the week and just topped up with fresh water.
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RobBrown

posted on 26/8/12 at 05:26 PM Reply With Quote
Hi guys

Now that I have sorted the crack, I'm still struggling.

I found that I can get the engine to run and idle OK, but when I take it for a spin there is no power.

I also found that turning the idle mixture screws did nothing (that I hear) to the engine RPM, other than affect whether I could restart or not.

Needle position 1 up from bottom seems to be better on the power. The bottom was too rich? black smoke etc. I get a lot of spit back on needle 2 up from bottom. 1 up from bottom still spits a little.

The main jet now drilled to 1.6mm (was originally 1.4mm) - not that this is kicking in just yet!

Any advice on what to try next?

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scoop

posted on 26/8/12 at 05:39 PM Reply With Quote
Put up some pics. Have you blocked the air jet yet?
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RobBrown

posted on 26/8/12 at 06:09 PM Reply With Quote
Which one is that. I assumed that it was A as it was already blocked?

Carb
Carb

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scoop

posted on 26/8/12 at 07:10 PM Reply With Quote
Ha ha. You've got me now. I would have said b. There are lots of threads on here about this or you can can always ring Bogg Brothers or I'm sure I've found articles with a google search.
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scoop

posted on 26/8/12 at 07:12 PM Reply With Quote
The idle screw adjusts the mix at idle and up to about half throttle. It won't adjust the idle speed. The dizzy setting does that.
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RobBrown

posted on 26/8/12 at 09:52 PM Reply With Quote
Looks like the correct one is already blocked according to another thread.

Previous Thread

Will try and ascertain where it is bogging down tomorrow, to try and figure out whether it is the idle settings or the main jet needle.

I've also read in other threads that some have gone to 1.8mm main jet. I'm wondering whether this is needed on my 2l with high lift cam?

Also as I have drilled out the jet whether the needle needs to sit lower - move circlip back to pos 3 on the needle?

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scoop

posted on 27/8/12 at 05:24 AM Reply With Quote
Have you removed any of the plugs and looked at the colour of them for a rough indication of how it's running? 1.6mm should be enough initially.
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scoop

posted on 27/8/12 at 05:28 AM Reply With Quote
It is timed up properly?
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FASTdan

posted on 27/8/12 at 07:52 AM Reply With Quote
I've only skimmed the thread but if you are still running the mechanical pinto pump you need to swap to a bike pump or similar. The pinto pump wont flow the fuel to run the bike carbs.

Genuinely not trying to flog you a pump (I have a stock of used bike pumps), but you may well end up changing loads of stuff on the carbs chasing a non-existent problem only to find when you swap the pump you need to start again.

Saying all that I didnt know you could run dellorto's on the pinto pump successfully....

[Edited on 27/8/12 by FASTdan]





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scoop

posted on 27/8/12 at 09:15 AM Reply With Quote
Forgot about the pump. With everything else you've done. There lyes the problem.
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RobBrown

posted on 27/8/12 at 05:00 PM Reply With Quote
Thanks all

Will fit a bike pump and see how we go from there. Will I need to run it through a relay or can I just wire it straight in to the main on feed?

FASTDan - Can you U2U me a price for one of your pumps please?

I came across this video which put all the jets into context with each other. Helped me anyway with my lack of understanding - YouTubeLink

Will update this post with progress.

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