Jet recommendations / carb work

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LewisB
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Jet recommendations / carb work

Post by LewisB »

Hey guys, I will be stripping my carbs soon as I’m got a very rough idle (I’ve owned the bike for a few weeks and was like this).
Another problem I’m having is crazy amounts of popping on deceleration. The bike has carbon quill end cans with baffles fitted and I’m assuming stock headers (although the header bolts on the engine look pretty new) and a stock filter. When I strip the carbs I will make a bit of what jets are fitted, but can anyone recommend what size jets I should be running that could help stop the snap crackle and popping?
Cheers.Image
Last edited by LewisB on Sat Mar 18, 2023 4:23 pm, edited 1 time in total.
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sirch345
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Re: Jet recommendations

Post by sirch345 »

You need The Workshop Knowledge Base :D

Have a read of this link: viewtopic.php?t=28922

Pop and banging on the over-run could be due to drawing in air on the exhaust system joint(s). Also as I mentioned doing before, carbs being out of balance, or a split in a vacuum pipe. However you may still get a small amount of that happening on the over-run with aftermarket cans,

Chris.
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LewisB
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Re: Jet recommendations

Post by LewisB »

Legend Chris thanks again!!
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sirch345
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Re: Jet recommendations

Post by sirch345 »

:thumbup:

This link may be of help too: viewtopic.php?f=9&t=25177

Chris.
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LewisB
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Re: Jet recommendations

Post by LewisB »

sirch345 wrote::thumbup:

This link may be of help too: viewtopic.php?f=9&t=25177

Chris.
Fantastic link thanks Chris! I like to get as much info before i do work so I’m not going in blind haha
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8541Hawk
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Re: Jet recommendations

Post by 8541Hawk »

The pops and bangs on decel can also be caused by a lean setting on the pilots. Check what the settings are and what size pilots you are running. I generally set them up with #48 pilots with the pilot screws around 11\2 to 2 turns out as a starting point. Now for mains and needles. It is pretty common for folks to want to install larger mains and adjustable needles. Neither of which is needed IMHO The stock needles work well (they are some of the best stock needles I have used) and for mains, I can only use mine as an example. STG1 eng with 120+ RWHP and the dyno says 175\178 mains are correct. I am rumming Dr Honda stck which make the jets "act" one size larger ...or the same as 178\180 mains with stock stacks which is why running large mains doesn't make much sense to me.....Oh and I also return 35MPG even with some "brisk" riding :wink: :thumbup:
Loud pipes don't save lives, knowing how to ride your bike will save your life.
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sirch345
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Re: Jet recommendations

Post by sirch345 »

Another thing I meant to mention. When removing the black plastic nuts (or whatever you like to call them) that hold the choke bits in on the carbs, go careful, as they are easy to break,

Chris.
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LewisB
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Re: Jet recommendations

Post by LewisB »

Thank you guys. I’m going to get the carbs out tomorrow if it’s not raining and I will update you with the idle settings and jet sizes.
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sirch345
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Re: Jet recommendations

Post by sirch345 »

Good luck with it, and the weather :thumbup:

Chris.
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LewisB
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Re: Jet recommendations

Post by LewisB »

Had a break in the rain this morning so I thought I’d whip the carbs off. Instead of disconnecting the tank (as I had about 1/3 tank of fuel) I thought I’d spin it round and rest it on the tail. All well until I turned my head towards the engine and noticed a 1ft long stream of fuel pissing out of the bottom of the tank! Trying to plug the hole in the fuel line whilst holding the tank, removing the vac lines and disconnecting the electrical plug and then reaching for pliers to get the metal retaining ring off the line to pull it off was fun! I ended Up just ripping what was left of the line so I could get the tank away quickly. Anyway now I need a new pair of shoes (the soles turned to jelly) and the fuel line from the tank to the petcock! Anyone have a diagram of the fuel lines of the later model so I can find a part number? Hope you guys are having a more productive day than me ImageImage
tony.mon
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Re: Jet recommendations

Post by tony.mon »

Your vacuum line is perished as well. You can simply trim 10mm from the end, but as you're already ordering fuel lines, you might as well replace the whole set.
It's not falling off, it's an upgrade opportunity.
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LewisB
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Re: Jet recommendations

Post by LewisB »

tony.mon wrote:Your vacuum line is perished as well. You can simply trim 10mm from the end, but as you're already ordering fuel lines, you might as well replace the whole set.
Good spot tony! I didn’t get a chance to inspect the lines as the rain set in so had to get the covers on the bike. I’m thinking instead of paying an arm and a leg for OEM lines I might just work out what sizes I need and buy some generic line and trim to length, that way I could just replace every line as I’m guessing more will need replacing.
tony.mon
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Re: Jet recommendations

Post by tony.mon »

I probably have a spare set, if you're happy to take 2nd hand ones.
Just photo the ones you need with a ruler in shot so I can see the lengths and dimensions.
It's not falling off, it's an upgrade opportunity.
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LewisB
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Re: Jet recommendations

Post by LewisB »

tony.mon wrote:I probably have a spare set, if you're happy to take 2nd hand ones.
Just photo the ones you need with a ruler in shot so I can see the lengths and dimensions.
Oh really! Yes that would be great thanks! In that case I will take so time tomorrow going over the hoses!
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sirch345
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Re: Jet recommendations

Post by sirch345 »

At least you have made a start and you didn't drop the petrol tank, although a shame about the shoes :wink:

How does it go again, "two out of three ain't bad" :D

Chris.
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