This is what a ran up in Oregon on my DS. 180 main, needle on bottom clip, and idle circuit 3-31/2 turns. It was stock except a CT pipe & K&N in box - lid off. Should be real close to how your set-up. All fourstrokes that i've ridden always pop & sputter when their cold, so I wouldn't worry about that too much. Put in a fresh set of stock plugs and ride it. Get it warmed up, set the idle circuit then take it on a good hard long acceleration(WOT). Then check plug - should be a light color (tan to white) After getting your main dialed in then adjust your needle to eliminate hesitation & gain crispness through your midrange. Hope this helps.

 

"The guys that sold me the MR.HP cap and filter
had me replace the plugs to lower heat range."

Why ?? And who were they i bought mine direct from hp reaserch and i have had a lot of usefull tips from eric that came as part of the customer service but no mention of changing plugs, And he did all the development on the end cap.

 

back to plugs i have had my bike jeted as far up as a 180 main that was with stock filter and end cap only. And although im almost sure it was a little rich at full throttle as the exauast was building up a little soot and it felt rich the plug insulator still looked white with maybe a slight smoke grey to it.

this is the reason i have trawled the net looking for good sites with photos,, i can read two stroke plugs fine but the 4's are a different story.

Any way im back to the start again now i have fitted the hp manifold i am on a 177.5 which feels a bit lean with the manifold on
i hope i get there before i get to the 182.5 as thatys the largest i have.

I was also thinking of a larger pilot just for saftey sake (had a bad experiance with a lean motor $$$) any thoughts or suggestions????

 

I bought my cap and filter from Kens Recreation in KY. From what I understand Eric and Randall work together. Im not sure of the connection. It didnt really make much sense to lower the heat range but there the experts so I went with the suggestion. Im currently reading up on the Mikuni carb and how they work. You guys have given me a wealth of info, Thank you. Im rapidly losing my fear of working on this thing. I have a manuel on CD coming soon. That should help alot. How do I contact Eric Oldham personally? Im going to be doing alot of mods in the future, Might be a good idea to go to the source.


Thanks again

 

The reason for a colder plug is to help eliminate pre ingnition / detonation
Normally a colder plug this is only needed when you start to raise the compression.
In your case you shouldn't need to use anything but a stock heat range plug.
The 4stroke artice that blue250r explains reading plugs perfectly and also covers this.
Actually that article is so good you really don't need pictures.
There is also a very good article in the tech section of the 4stoke site explaining carb circuits and how they work / relate to eachother. Worth reading as well[img]i/expressions/face-icon-small-wink.gif[/img]

 

Oops almost forgot yo wanted this too Eric Oldham / Oldham Machine 270-334-3331

 

Thanks to all that have helped me here. I think I have figured out the problem. I really hate to tell you
guys this but it was a really good lesson for me. I just discovered the the choke actually has two positions.
Half choke and full choke I think. Turns out I thought I had not pushed it all the way in. Also I think I over oiled
my filter. Any suggestion on how much oil to put on it? I installed new plugs gapped at .027 ran it through some hard
passes and checked the plug. The color is a light tan. It is pulling alot harder now and is running really good.
I think Im going to go ahead and order the ported intake from Mr. HP. am i going to have to rejett again?


Thanks again for all the info Im a little embarrassed about the choke thing but they dont call me Scatterbrain for nutin

 

Eric will advise you on jetting for the intake.

glad you got it fixed and dont worry about the two position thing you wont be the first or last to be caught out with that.

I went up to a 180 main today ran for about three hours seemed to run cooler and was bouncing of the limiter in top gear so i cant be far of at that , havent done a plug check yet as it was pi$$ing rain all day.

The manifold was well worth the money Some guys have done there own which is a good thing but For $150 dollars you get porting that was tested on a dyno to get it spot on and a few other pointers to make it all come together. bargain