XT600 / TT's sparkplugs

[bacardi23]

Hey ya'll!

Has anyone ever used plugs for an 84-89 XT600/Tenere 84-92 which uses the DPR7EA-9 on newer XT's such as the 1990-2003 XT600E / TT's which use the DPR8EA-9?

My DPR8EA-9's on my 1990 XT600E , according to this guide: Spark Plugs are very similar to the #4: Too Cold....

So, Pros and Cons of replacing the DPR8EA-9 with the DPR7EA-9?



Vando

[bacardi23]

same image as on the link:


#4



Vando

[GeoffE]

Hi,

It doesn't help, but I always thought the 8s were for normal running, and then use the 7s in the freezing winter to aid starting, etc.? I've used both.

I guess your plug colour, and living in the Azores, blows that theory away?

Geoff

[Jens Eskildsen]

I use stock plugs and the bike has been starting fine in -15 celcius.

The xt600e is usually not hard to start cold since it isnt high compression, and its slightly rich fromt he factory.

[bacardi23]

Well, thing is my rides are small in distance, kinda what you guys call "stop and go's around town"..(I live in a very small island lol)

In terms of elevation its very rarely (about 10times per year lol) above 300 meters above see level and in those cases for only about 2 or 3 miles(it's the highest hill here)..

Most of the riding time done is at less than 200meters and the "longest" ride, without stopping at other destinations, I ride takes about 40minutes(25-30km) from where I live to around the center of town and to the furthest point on the island within the speed limits lol.

There aren't any highways or speedways or interstates...

I know I'm still on the rich side with the jetting because before the bike wouldn't rev as good as it is now.
Plus there is still a slight hesitation at wot (much less than before I went down on jetting as I couldn't even go to third gear as it would start to hesitate and shut off)..


And I was thinking that maybe a DPR7, since it burns hotter, would solve my buildup problems due to the short stop and go's...

Thing is I'll be needing to check the DPR7 plugs very regularly.. every 15-30km maybe as I don't know how they will behave...mostly because absolutely love WOT (safe wot tho!)


The weather here is a lot of the times over 75% humidity and in the summer the average temperature in the summer around 23ºC and topping at 30ºC...


I'm also awaiting my lower jets to arrive.. so I'll also mess with them a bit..
I just don't know if I should put the same jets on both carbs or not... any ideas?

I've got 140 Left and 145 Right...


Oh, and she pops a bit under deceleration, probably a slight off-sync on the carbs..have to try opening and closing the 2nd carb bit by bit..

I know, a lot of info but essential to knowing my circumstances...lol

Vando

[Jens Eskildsen]

I sometimes commute to and from work, its only 4km each way, the bike does fine. The plug is not you're solution.

Stock jets are 130/120 on a less flowing carb, you could still be WAY of. With my ninja ex250 carb I have 110 mainjets, and they are sliiightly rich (tested with lambda probe-thingy), even with an oversixe header, laser exhaust and opened up airbox.

Stock is 130/120, i had 140/130, it was way rich at WOT (15-20% too rich from optimal burn), and I couldn't even feel it, and my plugs seemed spot on, they were never black. I had to have it dynotested to see the real picture.

I even had to lean out my stock carb with smaller mainjets, and lower the needle in the secondary carb for better riding.

Rejetting like this is really fumbling around in blindness, and I will never rejet without beeing able to test it.


The pic you have there might as well be from a bike burning a bit of oil, theres 1000 scenarios that could cause a plug to look like that.

Lean out the mainjets some more, and have the bike tested. Think about how much time you have spent on building and adjusting the bike. Toss in the last few bucks so you can ride and be done with it.

Best wishes

[bacardi23]

Jens, tell me your elevation from sea, temperatures winter and summer and humidity levels.

I've told you before that I don't want the sparkplug to be a specific solution..

As I've said before, all I want to do is get the jets sorted but until then a fix is also good!
And nope, no dyno's here so I'm out of luck on that too...

[Jens Eskildsen]

Temperatures are for very finetuning.

At sea level, winter is typical in the freezing range, i would guess it averages around -10 to -5 celcius. Summer is around 20-25celcius, but we have thosse 30 degrees days aswell.

The humidity now is 69%. (freezing, so fairly dry.)

I tried to make a test with my lambda-thngy. I saw no difference at all, riding in the night with only just above 0C, and riding in the day in sunshine at around 18C.

This is the weatherforecast for my region in Denmark, just for the fun of it:


[url=http://www.dmi.dk/dmi/index/danmark/regionaludsigten/ssjylland.htm]DMI - vejrudsigten for Syd- og S

[bacardi23]

Well, now I am confused... lol

I put some air in the rear tire although it goes flat after less than hour and went for a drive with the bike..

I pulled her a bit hard on straight road(because of the tire)to see how she behaved and it wasn't bad...
went to 125km/h and had to slow down because I'm not at ease with the tire like that..

on the way back I noticed she was kinda starving for fuel..So, when I parked in my garage I waited 5mins for the engine to cool a bit and toke the plug out...

it looks like this now:




And I was.. wtf?! in december with temps around 15ºC and 90+% of humidity it was all covered in black soot and only the end of tip of the sparkplug was light brown but now it looks like this!

Now it's a tad on the lean side..
Will have to adjust the floats again as they might be a little too low because before I only wanted to stop the carbs from leaking because of 2 bad o-rings on the float seats..

Guess I'ma have some more time at hand to tune her.. just need to borrow an oxygen sensor machine ...


Will see what happens!
Vando

[Jens Eskildsen]

That doesnt look bad at all, imo.

But you need to rigde wot longer for a perfect reading., then clutch in, use the killswitch, cruice to a stop and check plug.

Make sure there isnt airleaks and such. And if youre floatlevel isnt in spec, fix that first.

[Mezo]

Originally Posted by Jens Eskildsen

With my ninja ex250 carb I have 110 mainjets, and they are sliiightly rich (tested with lambda probe-thingy), even with an oversixe header, laser exhaust and opened up airbox.

What year of the Nija`s fit the XT`s Jens?

Mezo.

[Jens Eskildsen]

I actually think they all fit, there might be some jetting differences.

Mine was listed as to fit many model-years. Something like 1987-2003 or something like that.

[bacardi23]

Hey Jens, take a picture of those carbs...
let me see the choke mechanism....

maybe I can fit the choke mechanism from a ex250 on my rappy carb as they are both mikuni bsr's...