Carb Balancing Drill Bit method ??? & RO jets

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oldgreyandslow
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Carb Balancing Drill Bit method ??? & RO jets

Post by oldgreyandslow »

Tried this and unless I'm missing something the 1mm drill bit hasn't a hope in hell on my carbs.

Wound idle adjuster fully clockwise

No discernible opening at the butterfly, just abaout mamaged to get a 0.1mm feeler gauge in. 1mm drill bit? No chance

Anyhow balanced 2 to 4 then 1 to 3 then front to back, all ok with the 0.1mm gauge

Wound idle adjuster out a couple of turns and I assume job done?

On another note I got some new main jets from Rick O, to put everything back to standrad and the ones in the 118 bag are stamped 117.5 on the jet itself, the 115's are as marked.

Problem or go with it?
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CRM
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by CRM »

me too mate, all over the shop and rubbish uneaven tickover,
i simply adjusted the tickover until i could see the lip of the first air hole on the inlet with out the adjuster, then brought the rest to match with slight opening and closing of the butterflys to check the second was in view about the same time.
smooth even tickovers now
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Drunkn Munky
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by Drunkn Munky »

You to put a block in the throttle mechanisum to open them up a bit, then find a drill bit that just slides in the first one, then use the same drill bit and adjust the rest until it feel the same. Remove block, wind idle fully in then back off a couple of turns, start bike and adjust idle.

The 0.5mm jets will be fine, i thought 118F 120R was standard tho
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Martin
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by Martin »

Honda or rather Keihin, don't go up in 2's on their jet sizes, they go up in 2.5's i.e 115, 117.5, 120, 122.5 etc so that is perfectly normal.
Too spensiff!!!
oldgreyandslow
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by oldgreyandslow »

Drunkn Munky wrote:You to put a block in the throttle mechanisum to open them up a bit, then find a drill bit that just slides in the first one, then use the same drill bit and adjust the rest until it feel the same. Remove block, wind idle fully in then back off a couple of turns, start bike and adjust idle.

The 0.5mm jets will be fine, i thought 118F 120R was standard tho
So if they're all the same with the 0.1mm feeler gauge it should be Ok then?

Jap import standard jets, according to haynes and Cammo (I think I know who I'd believe first!) is 118r 115 f, or in my case 117.5 r 115 f I'm putting it back to standard and then putting the "can of unknown origin" on, see how it sounds/goes and take it from there.
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by Neosophist »

As been said.

Wedge the throttle open a little with something that won't move while your adjusting.

You'll see you have 3 adjustment screws... carb #2 is fixed, you can't adjust this, you adjust the other 3 to match it, (it's not like balancing an inline 4)

Wedge the throttle until the non-adjustable carb has a slight drag on the drill bit, then use the three adjuster screws to make sure the other 3 throttle plates are the same.

This is ok as a basic-setup to get the throttle plates opening at the same time. However, this does not take into account actual vaccumn differences in the cylinders due to air-flow, which is why a vaccumn gauge is used to measure the air-flow at the cylinders.

The morgan carb-tube is a doddle to use.. mines back in the UK but somebody on here might be able to lend you theirs to balance them properly...
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oldgreyandslow
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Re: Carb Balancing Drill Bit method ??? & RO jets

Post by oldgreyandslow »

Neosophist wrote:As been said.

Wedge the throttle open a little with something that won't move while your adjusting.

You'll see you have 3 adjustment screws... carb #2 is fixed, you can't adjust this, you adjust the other 3 to match it, (it's not like balancing an inline 4)

Wedge the throttle until the non-adjustable carb has a slight drag on the drill bit, then use the three adjuster screws to make sure the other 3 throttle plates are the same.

This is ok as a basic-setup to get the throttle plates opening at the same time. However, this does not take into account actual vaccumn differences in the cylinders due to air-flow, which is why a vaccumn gauge is used to measure the air-flow at the cylinders.

The morgan carb-tube is a doddle to use.. mines back in the UK but somebody on here might be able to lend you theirs to balance them properly...
Got it, thanks, I had a carbtune, used it on my old fazer 600 in line 4, no problems, sold it though when I went all modern and injection.

I'll set them up using the drill bit method for now just to get it running and see how it goes, next time I'm in serious tinkering mode I'll do it properly.

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