Mixture screw

[chaza]

Hi guys
This might sound a daft question, I have an ajs regal raptor, it has a twin carb, a pd26js wabron carb, on the fuel bowl there are two screws, they are not the drain screws, they are on the engine side of the carb, my question is, are these the mixture screws. I can't see any other screws and can't seem to find a diagram for this carb to find out.
Any ideas please.

Thanks
Chaza

[stinkwheel]

From pictures, if they are facing sideways, they are drain screws, if they are facing down, they are the mixture screws. Do not mess with them. Whatever your problem may appear to be, altering the pilot screw position is invariably not the solution.

Unless that problem is either "Someone has fiddled with my pilot screw and now my bike wont idle." or "I have radically altered the state of tune of my motorcycle and while it is idling pretty well, I think it could be tweaked so it runs marginally better."
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[chaza]

My problem is a small one, the bike is running a bit rich, the screws are facing down, so I wanted to weaken it a bit.
Cheers

[virus]

at what part of the rev range is it running rich and by how much?
____________________
own: 81 xs1100g...
owned: 85 rat CG (sold), 91 GS500e (stolen), 84 gsx400f (scrapped), 81 z250 (siezed, siezed, scrapped), 83 cb250rs (sold), 84 gpz750r ratfighter (killed) 84gpz400 (sold), '80 cb650 ratfighter (wrote off) 95gsx6/12f ratfighter (killed) 91 xj900 (sold)
stinkwheel Well I just had my hands up a pigs fanny. Which makes your concerns pale into insignificance.

[chaza]

I don't know what you mean, when I clean my plugs they are black indicating rich mix. She idles fine, it has a slight dead spot on the throttle.

Thanks

[virus]

different parts off the carburetor control the mixture at different RPMs, a basic plug check wont tell you what part of the rev range needs altering so you need to do a plug chop or a dyno run.

I suggest looking into plug chops, its cheaper than dyno time.

Cheers
John
____________________
own: 81 xs1100g...
owned: 85 rat CG (sold), 91 GS500e (stolen), 84 gsx400f (scrapped), 81 z250 (siezed, siezed, scrapped), 83 cb250rs (sold), 84 gpz750r ratfighter (killed) 84gpz400 (sold), '80 cb650 ratfighter (wrote off) 95gsx6/12f ratfighter (killed) 91 xj900 (sold)
stinkwheel Well I just had my hands up a pigs fanny. Which makes your concerns pale into insignificance.

[stinkwheel]

If it's idling normally, don't touch the mixture screws. they only control pretty much the bottom 10% of the rev range.

At what point of the rev range is this dead spot? Have you altered any of the engine componants from standard? When did you last clean your air filter?

Is it burning oil (you having to top it up, get someone to follow you and look for puffs of blue smoke under acceleration or on the overrun)? Black plug electrodes can also result from burning oil.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Triton Thrasher]

[chaza]

I have had to change the floats, the old ones were full of fuel which effected the buoyancy which is why it was pis sing fuel out of the overflow. So after reinstall, the rubber on the filter side are not on perfectly yet, but I started her this morning, she starts ok, she needs choke, but it is cold, the dead spot seems to be at the start, she seem to unresponsive for the first second or two.
I'll take her out for a test drive again, the last test was just a short one.

Thanks guys

[chaza]

I don't know what a plug chop or dynamic run is. No it's nog burning oil, she is a 12 plate bike
Cheers

[stinkwheel]

[chaza]

Thanks for that, the air box rubbers 90%just waiting on new clips, I took it for a run, I did 50 miles, it runs fine, except for the slight dead spot at the start of the throttle twist, thd push, pull cables seem ok, I can't fault it really except for the dead zone I mentioned. Maybe the filter is not fully home as it should be, I'll check later.

Thanks

[chaza]

Thanks for that, the air box rubbers are 90% in place just waiting on new clips, I took it for a run, I did 50 miles, it runs fine, except for the slight dead spot at the start of the throttle twist, thd push, pull cables seem ok, I can't fault it really except for the dead zone I mentioned. Maybe the filter is not fully home as it should be, I'll check later.

Thanks

[chaza]

Because the room to put the carb pipes back together is redicuouslying tight, can I remove the air box and replace it with an after market cone type filter.

Thanks

[Robby]

It will never run right on a pod filter. Stick with the factory airbox. Dipping the rubbers in hot water will soften them a bit.

When you changed the floats, did you set the float height properly? If the float height is wrong, its going to run poorly.

[chaza]

I agree with the airbox issue, i can't say yes to the float height, why would it run poorly. I was putting the rubbers back on today, although she runs ok, she don't idle like she should. I noticed when Rev her, the revs are taking longer to drop back.

Thanks

[Robby]

The floats set the fuel level in the float bowl of the carburettor. If the fuel level is too high or too low, the mixture will be affected. The procedure for checking and adjusting the float height will be in the workshop manual, as long as the correct setting.

So before you looking for new problems, fix the ones you know you have:
- Float height.
- Airbox and possibly carb rubber seating.

The revs are taking too long to settle down because it has an air leak on the airbox or carb rubbers. Possibly both. Get the carbs properly seated and tighten up the clamps.

[chaza]

Thanks Robby
You have been a great help, I've put her away for the winter so love got time now to sort it all.
Appreciated
Thanks