Running rich

[mthee]

The XBR plug is black & sooty after only 160 miles. In repeatedly rerouting cables recently, I noticed the thread on the plastic choke valve is knackered. The weight of the cable keeps it slightly tilted back, about 1 mm off its seat. Also, the needle itself seems worn?

[johnr]

shouldnt it be held onto its seat with a spring?

[trophydave]

As Johnr says those type of Honda choke plungers usually have a spring to hold them closed.Also they can suffer from corrosion that stops the choke from closing properly.

[SteveC#222]

Yes there should be a spring - I don't think it has a particular tension so something from a box of mixed springs from a hardware/ auto parts shop should provide something to do the job. (parts 14/18 & below)

[mthee]

The spring was absent, having pingged across the garage. It must have entered a tear in the space/time continuum fabric because it reappeared later in the middle of the garage floor, after I had systematically removed and replaced every single blessed item, looking for it... Grrr!
I don't suppose this might fit;
http://ruggedroads.co.uk/epages/00cbb604-5d1c-407e-8207-580e14387ec5.sf/en_GB/?ObjectPath=/Shops/00cbb604-5d1c-407e-8207-580e14387ec5/Products/7005

Otherwise, this is all I can find;
http://www.ebay.co.uk/itm/SUZUKI-RGV250-RG500-CHOKE-CABLE-GUIDE-13418-43410-/161139428351?hash=item2584a88bff:g:c3wAAOxyBjBTPrx1

So is the knackered thread and/or worn needle a possible source of the bikes rich mix?

[SteveC#222]

You can get a replacement valve/spring set on special order from David Silver but it's £44!!

I'd just buy a box of mixed springs for a fiver and try it, the valve is probably fine but the lack of spring means it won't be seating properly.

I'd try a few wraps of PTFE tape around the thread to see if it will hold.

[mthee]

Thanks, Steve, I'll try the PTFE trick. The spring was only lost temporarily. So the spring will seat the valve adequately, despite the plastic holder itself not seating quite right?

[SteveC#222]

If the PTFE tape lets you tighten the tread down it should hold - otherwise I might be tempted to try a little superglue on the thread ( yes I know it's a terrible bodge but needs must and you can get stuff to dissolve superglue that you can't do with araldite!!  )

[trophydave]

When I had my Africa Twin it was a common mod to blank off the chokes due to corrosion stopping them shutting off properly.Mine wouldnt start without the choke on cold days but a lot of folk reckoned theirs did.Basically you disconnect the cable,clean the plunger and the hole it sits in,put the spring on the plunger,pretty any spring that will go in the hole will do,then blank off the hole with one of the plugs that fit on the brake calipers over the ends of the brake pins.

[iansoady]

I don't think the needle is worn - that step is normal if that's what you're looking at.

[mthee]

Thanks, I thought it was too much to be wear, but wanted to check. Since the filter's clean, it looks like the carb needs to come off for a once over.

[SteveC#222]

Since the filter's clean, it looks like the carb needs to come off for a once over.

I wouldn't rush to take the carb off if you don't need to, it isn't the easiest job especially if the inlet hoses have got a bit hard with age. The rich running is probably just the choke needle not seating properly because of the missing spring or moving because of the knackered thread.

Find a decent hill and go up it at highish revs in 3rd so the engine is under load then near the top hit the kill switch and coast to the side of the road and whip the plug out (HOT) and check the colour.

[mthee]

Will do, Steve, thanks for all the tips 

[blew]

Get one of these.Throw away the brass bit and keep the screw thread and the spring.

http://www.ebay.co.uk/itm/Scooter-Moped-Manual-Pull-Choke-for-Keihin-PWK-Naraku-Stage-6-carburettors-/301973817019?hash=item464f0ac6bb:g:RVgAAOSw4SlV8smj

[timbo]

Yes, Blew recommended this mod before on a previous thread, and it is definitely the way to go. Don't mess about Matt, just order one