Anyone have a pic of what a perfect sparkplug color should be. Im having a hell of a time getting
my carb set up right. 05 dsViper, Mr.Hp cap and no toil filter. Im running a 170 jet and it keeps popping and
and snapping at start up. After it warms up it runs pretty good. The plugs are black. Would adjusting the needle help?
I am new to this and this is my first Quad.



P.S. Thank's to all who have answered my previous questions. This forum is awesome. Also I am usually a single rider
Anyone interested in a ride at Horsefall, Winchester, Florence, Christmas valley or maybe Sand Mt. I would really like to meet
some other DS owners to ride with. Im getting kind of tired of beating up the guy's in Blue! LOL

 

Most of the pics you find on the net are for 2 strokes and they always look for a tannish brown color, When I had my DS dyno tuned the plugs ended up being white-ish grey for peak power. That is what I always look for now. As far as your carb issues at start up, does it sputter and pop without touching the throttle? ( meaning at idle only) or are you hitting the throttle a little?

I'm just trying to determine which circuit in the carb is out of tune. If it's just at idle than you need to adjust the air/fuel screw so the bike starts easier. Most guys have that screw set at 3 1/2 turns out +/- 1/4 turn. If you get the poping only when you pop the throttle at start up, than you may just need to let the bike warm up completely be fore you hit it or re-adjust the needle to richen up the circuit. Popping or back firing can be a rich or lean symptom. Experimenting with it will do you good!

welcome to the forums!

 

http://www.4strokes.com/

you should be able to find pics of four stroke plugs in here i did but none of them look like mine ?
There are also a few differant schools of thought but it makes good reading

 

The tech section of the site that blue250r posted does have a very good write up on 4 stroke plugs. And IMO is spot on...here is a link to another aticle that backs that up with Plug Pictures

 

Eaglecollector, that link is for 2-smokes I do believe. The 4-stroke site is a great link!

 

Yes the 4stroke site is an excellent article and like i said is spot on
The site with the plug pictures is from exriders.com and is a honda 400ex site. But the impotant part is that the plug pics show what the better aticle at 4stoke.com talks about.

 

Your correct major...that article did not originate from ex riders. It came from a jet ski site and was posted in the tech section of ex riders[img]i/expressions/face-icon-small-sad.gif[/img]

Still no good 4 stoke plug color pics on the net

 

It doesnt sputter at cold Idle until you give a little gas. After it warms up it smooths out. I have a little black smoke
when I rev it up but it does clear out and run fine afterwards. Last night it got really cold here about 35. I took the bike off trailor
to put it in the shop and it wouldnt start (choke on or off). Pulled the plug it was wet. The guys that sold me the MR.HP cap and filter
had me replace the plugs to lower heat range. NGK DR9EIX 4772 Iridium. I put the stock plugs back in and it fired right up. I had alot less popping and snapping but It was still there. I ran it for awhile and checked the plug and it is black. Where do I go from here?


P.S. Thanks for the links on the spark plug color and jetting info. You guys rock!

 

I got this from the Mikuni site and found it to be accurate for jetting. You can use it to set the needle heigth as well by just going a little over half throttle in a mid gear and then letting off a tad. Gives the same result.

ROLL-OFF:

The Roll-Off technique is the quickest and is almost as accurate as the Roll-On method. First, one gets the engine warm on the way to a safe roadway. If there is room, use fourth gear as this allows more time to assess the result.

Now, get the engine rpm high enough that it is on the cam and in its power band. This may need to be as high as 4000 rpm with some cam choices. Apply full throttle. Let the engine accelerate for a couple of seconds until it has settled in and is pulling hard. Quickly roll the throttle off to about the 7/8ths position. When you do this, the mixture richens slightly for a second or so.

If the engine gains power as you roll the throttle off, then the main jet is too small and you need to fit a larger one.
If the engine staggers slightly or has a hard hesitation, then the main jet is too large and you need to fit a smaller one.

 

Scatterbrain,
pick up some new DR8EA ( stock plug) and chuck the old ones, sounds to me like you may be a little rich on the bottom with the bit of black smoke you are seeing( maybe the choke is not push in all the way after warm up). Do some reading up on how carbs work so you under stand how to tune the various circuits as they relate to the different throttle positions. Once you know how you will be empowered to do your own tunning and won't be at the mercy of a dealer. We'll help you thru it once you get a bit of an idea on how they work. Do a search on the net for Mikuni carbs and you'll find a ton of useful info. Did the guy who sold you the HP exhaust cap rejet your carb?
Until the bike is warmed up to normal operating temp I wouldn't worry too much about the popping when you blip the throttle- just about everything will sputter a little when its cold and you try to give it throttle right away.