To Dynojet or Not To Dynojet

[Geezer]

Anybody here try the Dynojet kit in a 78 or 79? I have the kit for the earlier bikes and it's been gathering dust for years and now I'm thinking just maybe I'll install it.

I bought it off eBay back when the company was closing out of them. I won't say what I paid for it but if had been around a hundred, I wouldn't have even considered it.

Geezer

[XJOK2PLAY]

Tony,
I see Bohn's bike is listed as an 1100 SG... an '80. He's got it in his... unbelievable improvement in MPG...

Miles Baker recently put one in his '81 Special... same results.

Mine's an '82 XJ, still playing w/ mine... already have seen a 6 mpg increase.

You might try one out. Adjustable needles are pretty trick.

Main reason I did it was extended range per tank... which makes it a mod that pays ya back...

If you've already got one, I guess the only reason I wouldn't install it would be if your bike already achieves low 40's...

Mine's best ever was 32... usually 30. Now I'm seeing 38, and improved, smoother power band.

First thing I checked out before hand was what these bikes got for mpg new...and discovered it was a whole lot better than 30.

[MrOzz]

Im running the DJ set up as well,
was wondering what youre all setting the mixture screws at?
The kit says 4 turns out, but that was way to rich for the bike,
im running it at 2 turns out.

Im also running the 128 main jet, pod filters/4-2-1 exhaust
needle set at 2nd clip
23mm float height

I have the mixture screws at about 2 1/2 turns out. I am running stock exhaust. Using a k & n airfilter in stock air box. Might go with pods.

Dont know what I am getting for MPH right now. But the throttle response is smother/quicker.

I got lucky found it at a local shop. I paid 75.00 for it. Last one that they had collecting dust in the back room.

Ozz


Ozz

[Ivan]

I have pods and a Jardine spaghetti exhaust. The DJ kit is set per instructions on stage 3.

Idle is smooth, and I didn't even have to adjust the idle speed. I did set the mix screws at 4 turns per the instructions, and it works well. I can try fiddling with the idle mix, but I don't think that has much to do with anything above about 1/4 throttle or less.

Truthfully, everything runs smooth and pulls good, but I just don't feel a change.

Maybe its time to put a wide band O2 sensor in the cross pipe.

[Geezer]

The 78 and 79 already has adjustable needles. I need to check the mileage again since I've done some work to it. The PO said he was getting 45 MPG at under 65 MPH but it went to hell at over 70. He told me this when I was working on it for him a year before he sold it to me...

I tend to wick the throttle a lot so I haven't gotten more than 38 but the last ride I checked the mileage on a trip the rear brake was dragging.

Geezer

[XJOK2PLAY]

Update...

I just got back from a 1000 mile weekend ride...
Stillwater to Eureka Springs, Eureka Springs to Hot Springs, Hot Springs to Mena, Mena to Talihina over the Talimena Drive, (ate lunch today at Pam's Hungry Hussy Cafe... it was great...) back to Stillwater by way of McCalister, Glenpool, Tulsa... Hwy 412 W.

Going to Eureka Springs... wasn't happy w/ MPG's... again average dropped back to 32.

So, last night in the Holiday Inn Express parking lot, we pulled the carbs, dismantled, and dropped the needles to the first notch from the second.
Bamm... still ran great, mileage jumped consistantly up to 38 now. Still got a few more things I want to do tuning wise... but the lower you put the needles, the better it seems. For the first time since I've owned this bike, I went to 150 miles before reserve, and had a total of 170 miles when I put in 4.4 Gals. (38.6 mpg)

XJ tank holds 5.1 gls. so, theoretically, I should get 197 total to empty... that's up from 150! And that's what I've been looking for... the extended range & better performance from a mod that pays me back with every fillup... especially with today's gas prices!

Our average speed was around 75, more or less. A lot of highway, some city stop & go.

Overall, even before we dropped 'em another notch last night... I was very pleased w/ the way the bike ran. Much smoother... and we got all the idle problems solved... returns instantly & consistantly now back to 1100, just like it's supposed to. (Whew... that was a mess for a while...)

If the weather holds up, Talimena should be great! Beautiful there today... and the weather was perfect. Views were spectacular!

Ohhh.... We weren't aware that there was a massive Harley Ralley going on in Fayetteville this weekend when we left... I have never seen so many Harleys... and most of 'em were right in our way, all just begging to be passed... LOL

We were told that there were an estimated 400,000 bikers in the area this weekend... I'm still trying to get the ringing in my ears to stop...

Had a REALLY close one today on the Talimena Drive... Deer jumped right out in front of me... she was really scrambling for traction on the asphalt, as was I... (the deer- major acceleration, while I grabbed for major, rapid deceleration...) missed it by about 3 feet, (1/2 second.) (Whew!!)

We're all going to have to watch for that on the ride...

Great ride, though. Bikes made it home successfully, no tickets, no wrecks, no breakdowns...which is always a major plus!

[MrOzz]

XJOK2PLAY,

Are you colortuning and then syncing your carbs between every change?

Ozz

[XJOK2PLAY]

Not having to resynch for needle position changes only...

If you were to change jetting, or alter the screw adjustments somehow, which would change throttle plate relative positions... you'd have to resynch.

[Ivan]

Well, I messed around with my kit this week.

First I went from the 138 (stage three) jets to the 128 (stage one with aftermarket exhaust). It was too lean, so I went back to the 138 jets and moved the needles down a notch, to the first groove. This made the low end stumble terribly. A couple times it actually died on full throttle when taking off. So I moved them to the third (middle) groove.

WOW, there it is. from 1200 to redline it pulls like a freight train. I am starting to think the money was worth it now.

[jeffnew29]

Rebuikd Kits

Could you guys tell me the model of the carbs for the 1982 XJ1100J? My carbs need rebuiding and was wondering about rejetting for Denver elevation.

Thanks for your advise.

[XJOK2PLAY]

XS11.com Forums > Maintenance > Carburetors
Carburetor Facts - Models and Jetting


Check out this chart... maybe it will tell you what you need.

Usually, if you order a rebuild kit, or a Dynajet kit... when you tell them it's for an '82 XJ1100J, that's what they need to know... since it was only built the one year.

[XJOK2PLAY]

Ivan,

I've been told that the jets aren't really the big deal... it's all in the needles.
(But I do think if your needle jets are egged or worn, that's half of it too.) And I believe over time, that's what wears down, and causes it too richen up the mixture at cruising speed, which drops the fuel mileage.

That's quite a difference from mine... you tried to go to the first notch & it worsened, which is where mine excelled & got the best mileage finally!

Now you're in the third... but, you probably have more mods than mine does, which makes all the difference.

Cool you're seeing improvement!

[Crazcnuk]

Mikuni says that the needles in the BS series can wear in as little as 5000 miles.

I think a lot of the bikes that have poor mid-range fuel economy have worn tubes/needles.

[XJOK2PLAY]

Gee... that's good news...

I'm hoping these don't wear out that fast... that could get to be expensive quick!

[Ivan]

Well, I think my tubes are different than they should be, they had some number with 300 on the end, and I have never seen that in any of the stock tube listings.

My tubes don't look at all worn, and there were no witness marks on the old needles that I could see.