00wr400 jetting mistry
Posted December 17, 2000 - 07:43 PM
00 wr stock setting____________Mine
Pilot screw 1 5/8_______________1 1/2
Question #1: My Plug reading is slightly rich?
I put a new plug in, ran it through a field three times, pulled the plug. A little rich?
How can it be rich?
Question: Has anyone heard of an OBDTL needle. It has OBDT stamped on it at the top and then a blank space, then the letter "L"?
Question: How can this bike be running rich with a 165 main and smaller 38 pilot with the pilot screw at 1 1/2?
The bike runs fine, but after reading the forum, I was compelled to check mine. I expected a large main and pilot, and possible the needle at #4. I felt I would change the needle to the DTM with a 172 main and 45 pilot. But now that I see what's in it, it seems that these changes would only make the bike richer which it dosnt need?
[This message has been edited by miked (edited 12-17-2000).]
Posted December 17, 2000 - 08:13 PM
OBDTL is one step richer on the straight diameter than a stock '99WR needle - OBDTM.
This is the first time I have seen anyone use the L other than myself. It was for evaluating the richer option EML - with a 2.705mm straight diameter before the taper starts. I found it to be rich just off idle and not anywhere else. This explains the small (38) pilot jet in your bike. The main jet is not important unless you were only riding at full throttle and shut down at speed from a long run. If you are running rich 0-1/8 throttle, it is likely from the L.
There is nothing wrong with this setup. A bigger main might give you more top end (172-178). The #3 clip position is a good choice.
If it starts to foul plugs, think about switching to a leaner DTM, DTN, or DVP in that order. The bigger pilot jets work well with these and help to reduce stalling at low speeds.
Posted December 17, 2000 - 08:29 PM
That explains my plug readings. I felt it must have been my needle, but I have not seen anything on that needle in my book or on the forum. Do you think my bike would benefit from making the change to the DTM needle, 172 main and 45 pilot over what I have. I appreciate the quick responce. I was planning to go to the Yam shop. Need a 185 shim.
Posted December 17, 2000 - 10:09 PM
DTM and DTL are very close to the same. It is difficult to say you would be able to notice this change.
The pilot sounds small, but if it runs good and doesn't have a problem with stalling there is little reason to change at this point. ( if it ain't broke, don't fix it! )
It's hard to know without riding and comparing in your specific conditions.
Posted December 17, 2000 - 10:58 PM