JIS Screwdriver for 400/4 Carb slide screws -Trying to source correct fit please

[400 Cafe Racer]

Hi Guys,

I need to adjust the Carb needles onto the next slot down, the PO has set them too high and now float levels are correct its far too rich. He has lifted the needle 1 extra notch to gain more power, but they are far too rich on steady cruising. The A/F ratio is about  9.5:1, so I think they need to go back to the standard position.


Having looked at the access within the slides there is little clearance to get a screwdriver blade of small diameter down to the JIS screws to be removed in order to change the needle height, it is also a bit difficult to judge the correct snug fit head size. The "T " bar JIS set I have is too wide to reach down, but the US Pro JIS screwdriver set looks a possibility.

The heads of the screws look good, but they seem very tight. I just want to ensure everything is a good fit, rather than risk chewing the screw heads badly.

Can you advise from your experience on  the cabs, which is a good fitting tool/screwdriver please.

Many thanks

Dennis

[Kelly E]

Have two sets of JIS screwdrivers, my favourite set is the Vessel Impacta set. They are quality JIS screwdrivers that are also impact drivers. They have saved my butt many times, awesome for removing stuck engine cover screws.

[McCabe-Thiele (Ted)]

I bought these sorry can't remeber which one fitted - not top quality but they have done the job.
My impact ones are just the short type that go straight into my cordless tool for engine case bolts.
https://www.ebay.co.uk/itm/333425969113?hash=item4da1bc87d9:g:9LcAAOSw-eld6T6v

[Seabeowner]

On the 500 I have always used the Honda toolkit driver with T bar. I think the slide is 26mm o/d on these. You're right the screws are firm, but grip the slide in your left fist (if you are right handed) and press the driver into the head and they break free. I suggest using the biggest dia shaft as you can.

[TrickyMicky]

Definitely a JIS No.1 driver. The T-bar in the original Honda toolkit is perfect. screwdriver 'bit' sets are ok, but the bit holders can sometimes prove to be too wide for confined spaces. JIS conventional screwdrivers are worth investing in.  If you wnt to play around with really small stuff, try and lay your hands on a camera screwdriver set, very small but still JIS standard.

[ST1100]

I too vote for Vessel screwdrivers...
I also got me a 1/2" Vessel bit-set for the air rattler, as well a small 1/4" Vessel bit-kit for the tiny BOSCH GDR 12V-110 cordless impact wrench, way gentler then the impact thing you've to beat with a hammer...

[MrDavo]

I have an excellent pair of stubby blue JIS scewdrivers, a fine point and a more blunt one, as well as a long shafted driver. I got them via eBay. The downside was they were packed in a stupidly big box, that took weeks to arrive from Japan. I've never had much luck with toolkit drivers, maybe they are worn out by the time I get them.

That said, the one screw they couldn't get out was one of the tiny screws in one of my Z1 carbs, which I needed to shift to move the needle, so exactly the same screws, albeit Mikuni not Kehin. The one that was well and truly stuck started to chew the head up rather than budging, so I took it to my bike engineer mate, who used a pillar drill to get it out. He didn't want to use heat as he was nervous about distorting a slide that is a very close fit.

 

[AshimotoK0]

These Vessel Megadora ones are the set I have.

https://www.amazon.co.uk/Vessel-Megadora-2x100-2x150-Screwdriver/dp/B071SGNCSM/ref=asc_df_B071SGNCSM/?tag=googshopuk-21&linkCode=df0&hvadid=275572147651&hvpos=&hvnetw=g&hvrand=4669659623408723948&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006816&hvtargid=pla-535055156089&psc=1

[hondarc166]

me to Ash good product

[400 Cafe Racer]

These Vessel Megadora ones are the set I have.

https://www.amazon.co.uk/Vessel-Megadora-2x100-2x150-Screwdriver/dp/B071SGNCSM/ref=asc_df_B071SGNCSM/?tag=googshopuk-21&linkCode=df0&hvadid=275572147651&hvpos=&hvnetw=g&hvrand=4669659623408723948&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006816&hvtargid=pla-535055156089&psc=1

Thanks Ash and others for your replies, most helpful.

Ash

I selected the Amazon link which took me to a choice of 4.

1. The opening item describes the set as:Vessel Megadora 900 +1x75 +2x100 +2x150 Cross Point Driver Set of Three Items Original Silicone Cap .  It doesn't specify JIS on these. 

2. There is a JIS item listed below a: Vessel Megadora 980 Impacta P2x100 P3x150 JIS Cross Point Screwdriver Set of two items Original silicone cap .

Could I confirm please if it was the item 2 that you recommended or is it a different model.?

For the carb slide job I would prefer a solid normal twist non cam action. rather than an impact, due to the frailty of the surrounding components.

The shanks on these look slimline enough to get through the tight space to reach the screw heads.

Thanks

Dennis

[400 Cafe Racer]

Thanks for the update Oddjob, also thanks to Ash and everyone else,

From what I can see from the small space down the inside of the Carb slide, the screw head looks like a P2 size. I have ordered the one I refered to on the link from Ash, since it was the last one in stock and one of the reviewers specifically refered to its usefulness on the Carbs. I will have to wait and see when it arrives, but will be a good addition to the tool kit in any event.

The "T" bar JIS set I have with 6 bits has been really good on all other main casing screws, giving a good solid purchase even on some partly worn heads, with the T bar giving good stability and torque, while turning to tighten or loosen the screws. The shaft is just too bulky to fit inside the Carb slide for the main tapered needle notch adjustment job.

For the benefit of the specific job of getting to and adjusting the Carb needle height, I will give feedback later which may help others.

Cheers

Dennis

[AshimotoK0]

I was wrong, my set is slightly different to Ash's, I have a No1, No2 and No3 screwdrivers in my set, the one Ash has linked to has 2 No2. screwdrivers and you really need a No3 for the casing screws.

Got mine here.

https://ruggedroads.co.uk/epages/00cbb604-5d1c-407e-8207-580e14387ec5.sf/en_GB/?ObjectID=7575847

Cheaper than Amazon for the same set.

Sorry Ken .. I got it wrong .. mine are Vessel Megadora but  actually the same sizes as yours No1, No2 and No3

[Honsa]

I bought some German Wera 'Kraftform Comfort' Philips drivers, they fit the screws on a 400/4 perfectly, and are easy to source e.g. eBay.
          Graham