pods

[renobruce]

i need to find an oil cooler set up like that too...thats the cats arse...

Here's a link to the pics of my whole project if it helps.....

http://s19.photobucket.com/albums/b182/renobruce/GS1000/

[Mark M]

Yes, stock VM26's with the DJ kit and K&N's... #2454 I think? Can't remember. But they are the same for all the VM's for the 750, 850, and 1000

Now that is one CLEAN engine. Great work, Bruce.:-D

Mark

[TheCafeKid]

yeah i was just about to ask, looking at your photobucket stuff...what did you use to clean that thing?? It looks AWESOME...

[renobruce]

Now that is one CLEAN engine. Great work, Bruce.:-D

Mark

Thanks, Mark!

yeah i was just about to ask, looking at your photobucket stuff...what did you use to clean that thing?? It looks AWESOME...

Simple Green and lots of toothbrushes and baby bottle brushes. Scrub, scrub, and scrub some more. And then scrub some more......

I've since used the Purple Power stuff and it works good, too.

[renobruce]

dude608,
Sorry if I highjacked your thread a bit...

What bike do you have?

When going to pods you usually always need to re-jet. The easiest way is to buy a Dynojet kit if it is available for your model. If a kit is not available, ask for help here on the GSR. Someone will help you get it dialed in. Will you also be running an aftermarket exhaust or the stock one? That will also make a difference as the aftermarket exhausts (most of them) will add some extra flow as well.

[Mark M]

dude608,
When going to pods you usually always need to re-jet. The easiest way is to buy a Dynojet kit if it is available for your model. If a kit is not available, ask for help here on the GSR.

Getting back to the original question, I would be amazed if you could replace the stock airbox with pods and not need to rejet. These bikes (actually, pretty much any carbureted bike from the late 70's on) are all jetted quite lean for emissions purposes. Especially on the pilot and lower needle cicuits, where the EPA testing is performed. So, it already is borderline lean in the stock configuration. Then you put pods on and increase flow by a major amount... That demands the jetting be corrected or it just will not work properly. Unfortunately, there is just no way around that. As Bruce said, start with a DJ kit if you can and ask questions on these forums. Carb tuning is not black magic, it just requires a little bit of knowledge, time and a methodical approach. Especially a methodical approach.

Mark

[BassCliff]

To jet or not to jet. That is the question.

Hi,

Ms. SqDancerLynn1 pointed out motorcyclecarbs.com in another thread and this particular page is full of "rule of thumb" jetting guidelines that may come in handy as a reference for us novice carb mechanics.

Thank you for your indulgence,

BassCliff

[the_journeyman]

In a couple days, I'll give an update on how the DJ jet kit affected my GS1150 with pods & a 4-1 pipe. When I got into the carbs, the PO hadn't make ANY changes and it bogged badly on acceleration ~

JM

EDIT: That's pretty accurate BassCliff, I went from 132.5 to 138 per Dynojet's reccomendations on the main jet. That guide may help me fiddling ~

JM

[Mark M]

Hi,

Ms. SqDancerLynn1 pointed out motorcyclecarbs.com in another thread and this particular page is full of "rule of thumb" jetting guidelines that may come in handy as a reference for us novice carb mechanics.

Thank you for your indulgence,

BassCliff

The jetting guideline is pretty decent for getting the mains correct. Unfortunately, that is the easiest and least sensitive part. Getting the pilot and needle circuits right is much harder and requires more fiddling. You don't even need main jets in place to tune the pilot and lower needle circuits, you can just leave the main jets out until you are sure you have the pilot stuff sorted. At least you can on the BS carbs, I am not sure of the VM ones as I've never tinkered with them.

Since this thread is about carbs and it seems there are a lot of novice carb tuners looking in, this is the correct tuning sequence (for BS carbs, that is):

1. Pilot first. Get it sorted with the air screws until it idles and runs ok at small throttle openings. If you get to more than 3 turns out or less than 1 turn out, you need to change your pilot jet to the next size up or down, as the case may be.

2. Needle. Once you have your pilot set, start trying part throttle settings and see how it runs on the needle at part throttle settings. This area can be hard to diagnose rich/lean and often you have to try the next needle setting to see if it got better or worse before you know which way is correct. If in doubt, go richer first because a rich condition won't damage your engine like lean can.

3. Main jet. Once you are running good from idle to bigger throttle openings, then you can start sorting the main jet and doing plug chops to get it right. Remember, that slightly rich is OK and will not affect how your bike runs while being safer in spring/fall and on those hot days in summer when you just have to let her breathe a bit.

Remember, it is throttle position, not rpm or road speed that determines which circuit you are running on. The pilot controls from idle to around 1/4 throttle, the needle controls 1/4 to around 5/8-3/4 and main is WOT. These might be slightly off, it's been a while since I worked on this. Keep these in mind when road testing, it helps a lot to put a piece of tape on your bar and your grip with markings for full, half, 1/4 etc. to let you see how much throttle you are holding while testing. The reason you start at the bottom and work your way up is that the lower circuits affect the higher ones, but not the other way around.

Mark

[hampshirehog]

You can gain a bit of leeway on your pilot jets by adjusting the fuel meter screw - it's a bitch to do though as you burn your hands using the world's shortest, thinnest screwdriver right up against a hot cylinder. And you need to be real careful as well, as the end of those screws are very, very fragile and can easily snap and get stuck in (no need to ask me how I know that and the broken tips are a grade one bugger to get out). As you are doing 2 variables on the same line now you have to match each carb as closely as possible on the airscrews to get a good balance at tickover.

A colourtune makes the whole thing a lot easier and is now an essential part of my kit.

The slide cutaway also has an important effect at around 1/4 throttle - if you like it takes over first once the pilot circuit has finished its job. I've messed around DIYing these a few times to get the 'perfect' set up but I don't bother anymore as it's not easy and you need to be prepared to bin ruined slides if you're as cack handed as me. In practice, you can get it close enough so as not to notice.

Absolutely sound advice already about different pods but you can't over-emphasise; different makes will need different set ups.

And my view on Dynojet - there's no need to run to that expense (and aren't they bloody expensive for what they are?) as with VMs you've got plenty of adjustable elements anyway. In my book, if Dynojet are as hot as they claim they should be selling the reshaped slides as well.

Wally