XJ1100 with Dynojet?

[KA1J]

Seeing as a PO put on a 4-1 exhaust and the air filter is badly needing replaced, I've been trying to decide what to do; it appears to be running lean. If I replace the filter material with a washable material, it'll throw off the jetting even more.

I'm wondering if I were to get the K&N clones and a dynojet 4101 kit set up as stage 3, if that wouldn't be a reasonable way to go as that kit is for the 80-83 XS - XJ1100.

The main questions I'm wondering in this regard are:

If it aspirates and exhausts better I'll expect to get more power but will I get better mileage if I don't change my driving style & keep driving like the geezer in training I already am? I like having all kinds of power but don't really use it that much except sometimes when passing someone when I have to do it quickly.

And...

From the Dynojet page regarding stage 3 jet kits: http://www.dynojet.com/jetkits/index.aspx "Intended for motorcycles with stock or mildly tuned engines using a well designed aftermarket pipe and individual air filters. In most cases power increases of 10-15% can be achieved. However driveability may be compromised particularly with short stroke, high rpm motors. On some modern engine and airbox designs, individual filters and proper jetting offer no performance improvement yet compromise driveability, in such cases stage 3 kits are not available."

So...if anyone's done this with a 80-83 XS - XJ1100, were there any liabilities or negatives you've discovered since making that "stage 3" change?

FWIW, I do have a colortune & Carbtune and am used to using them on the XJ650J so I can adjust & sync as needed.

Thanks!

[KA1J]

Re-reading what I'd asked of the collective, it was perhaps the following quote regarding the Dynojet that was among my major concerns:

However driveability may be compromised particularly with short stroke, high rpm motors.

It's this "driveability may be compromised" statement that tells me there may be a permanent negative in function in doing the conversion and this is one of the things I would like to hear about if you have personally done the stage 3 conversion.

[crazy steve]

Well, seeing how nobody else is jumping in (as I type this), I'll give you my personal opinion of Dynojet kits.

While I haven't seen one of their kits used on a XS, I have seen them used on 'other' bikes. Their main advantage (as far as I can tell) is they contain a 'correct' rejet in a box if you've made changes to the bike. This may or may not save you some time and money in selecting the right jets for your particular application. Their higher 'stages' attempt to gain a bit of power, but the usual result does seem to be a loss in 'driveability', as I've seen more than a few of these kits removed for just that reason. Another issue (rather serious) is some of their kits require non-reversable changes to the carbs, so if you're unhappy with the result, you now need to replace the carbs or purchase some rather expensive parts to replace the modified ones.

If your current jetting combo is off, a Dynojet kit can offer an improvement, but from what I've seen, you can get the same or better results by using OEM parts; it just may be a bit harder to get there. Worn main jets/needles bear looking at.

Assuming the carbs are in good mechanical shape and properly jetted, a Dynojet kit won't improve fuel economy.

Definitely a case of YMMV...

[yamahansolo]

I have read what you asked about dj in my dennis kirk catalog. It goes on to say that they don't make the stage 3 or 7 kits for those bikes so we are not in that category. Hence the reason they have a stage 3 for our bikes

[DGXSER]

Have not used the DJ kit, and do not own an XJ. However, I do know of a couple members here that do not frequent the site much anymore who did install the DJ kit in their XJs and LOVE it. They had been through their carbs over and over and could not get them to tune. However, once they installed the DJ kit they could get the bike to purr and their milage did improve.

I will also say that I have owned a couple XS11s and worked on several others, and none had the DJ kit. All of them were able to be tuned in nicely and get good MPG.

So, I'd say they can produce good results, but IMO, they are not necessary to get the same results.

[xsroadrunner]

I know of a friend with an XJ who tries the DJ stg 3 jets. They were awful. Thus I do not suggest you use them. They were not the correct size for the bike. Bike ran like crap with poor off idle response. Also be careful with K and N clones. Some of them have an internal lip that will result in really poor airflow. There should be no lip. It should be one flat uniform surface. Maybe someone here can illustrate.

[KA1J]

G'morning,

Good answers coming in regarding my questions. As far as I can tell, I think I'll be keeping this bike for a very long time and want to make wise choices.

XSRoadrunner, I have seen photos of some of the cheap pods that obscure some jets and I'd of course want to avoid those. I wonder if the friend you knew with the poor results may have used similar pods and not known the difference?
I wonder which aftermarket pods are as good as the K&N?

To pay the price of K&N pods is out of the question. I do have a K&N in my Subaru and bought one for my XJ650 but never used it because I didn't want to rejet the carbs.

If I had stock exhaust on the XJ11 I'd be happy to stay stock all around but seeing as there's what looks to be a 4-1 MAC already on it, I may as well go with better aspiration and rejet accordingly. It would be a Royal PITA to have to keep removing the carbs and rejetting to play with different jet values and if something like Dynojet has a formula like XS/XJ1100 + pods + 4-1 = kit 4101 and this works out of the box, it would be worth it not to buy a myriad of jets I don't need.

If Dynojet stage 3 is hype or if it brings liabilities as in driveability (whatever that really means) it's a deal breaker. If it's a positive benefit and makes the aspiration/expiration balanced throughout the range, it's a win.

This is what I'm trying to find out before buying something I don't know enough about

[CatatonicBug]

The only "permanent" change that needs to be made to the carbs is drilling out the air return hole in the slides. You could do that without the DJ kit, and it wouldn't hurt anything. I have the Stage 1 kit in my MNS, and noticed an improvement right off the bat. Since I don't run pods or a 4-1, I can't say how well the Stage 3 works, but DJ seems to know what they're doing. It took some fiddling with float levels and other tuning to get things right, but I do like the increased MPG too.

[xsroadrunner]

G'morning,

Good answers coming in regarding my questions. As far as I can tell, I think I'll be keeping this bike for a very long time and want to make wise choices.

XSRoadrunner, I have seen photos of some of the cheap pods that obscure some jets and I'd of course want to avoid those. I wonder if the friend you knew with the poor results may have used similar pods and not known the difference?
I wonder which aftermarket pods are as good as the K&N?

To pay the price of K&N pods is out of the question. I do have a K&N in my Subaru and bought one for my XJ650 but never used it because I didn't want to rejet the carbs.

If I had stock exhaust on the XJ11 I'd be happy to stay stock all around but seeing as there's what looks to be a 4-1 MAC already on it, I may as well go with better aspiration and rejet accordingly. It would be a Royal PITA to have to keep removing the carbs and rejetting to play with different jet values and if something like Dynojet has a formula like XS/XJ1100 + pods + 4-1 = kit 4101 and this works out of the box, it would be worth it not to buy a myriad of jets I don't need.

If Dynojet stage 3 is hype or if it brings liabilities as in driveability (whatever that really means) it's a deal breaker. If it's a positive benefit and makes the aspiration/expiration balanced throughout the range, it's a win.

This is what I'm trying to find out before buying something I don't know enough about

To answer the part you addressed to me. My friend bought the genuine K+N's. It was the jetting that resulted in his poor performance. It was his ignorance in thinking the DJ stg3 jets would be good on his bike. When in reality the stg3 jets are for more high performance and higher rpms at the expense of normal everyday low end acceleration and fuel economy.

[yamahansolo]

Hey Gary,
You should go with the mikes xs ones. The are identical to k and n. They were 16 bucks a piece from mikes xs. Go to his site and look at the pods for the 34mm carbs. Just don't tell him you have an 11. Look at any of my photos and you can see them. The ones that have the lip look like tc's and are made by emgo. Tc moded his to work better go to the mods section and he has a write up about it.
Chris