Eats GAS, runs flooded-NOW what?

[XJOK2PLAY]

Hey Ivan, and the other low gas mileage gang...

My XJ used to get consistently between 30-32 mpg, no matter what.

Went through the carbs several times... ran good, just lousy mileage.

I was like others... thought 32 was normal. Then one evening I posted here in another thread & asked what the bikes used to get when they were new... for those guys that had bought their's new and still had them today.
Some of the responses said over 40. That told me something wasn't right.

Put a Dynojet kit in, played with the needle settings a few times, was able to run the needles on their lowest settings finally, and bingo! Mileage has improved between 37-40.

Now, I will say if I run turnpike speeds a lot... between 75-85... it'll drop to
35. but if I keep it under 65, it gets better.

There's a lot to those adjustable needles, and also replacing the old ones w/ new needles helps.
Might be worth the $ to you, Ivan to give it a try. Even for the guys that already have adjustable needles, they wear, and there goes the MPG's, IMHO.
From what I've seen so far, the Dynojet boys got it right.
JAT
Bob

[Ivan]

I have Dynojet kit, and if I drop the needles, it hesitates and runs like crap in the mid range. If I raise them up, then it pulls like a freight train, but the mileage isn't so good. But I was running the DJ jets, which are not the greatest IMHO, so I went back to Mikunis again. Will this tuning ever end?

[XJOK2PLAY]

I have Dynojet kit, and if I drop the needles, it hesitates and runs like crap in the mid range. If I raise them up, then it pulls like a freight train, but the mileage isn't so good. But I was running the DJ jets, which are not the greatest IMHO, so I went back to Mikunis again. Will this tuning ever end?

Wow, sorry to hear it didn't work out for ya on yours...

I wonder what's the difference? On mine, not only did I see fuel mileage increase, but even when I first installed it and I didn't have the needles set to the spot they're in now, I saw major improvements in the way mine starts faster, idles better, and in the power curve. I was told sometimes as you drop the needles looking to increase mileage, sometimes it'll effect the way it runs... from leaning it out too much. Probably just got lucky then that I was able to drop mine to their lowest setting and still got it to run good...

You've got a Special, right? And didn't the Specials already have adjustable needles? Maybe it has something to do w/ the differences between our carbs, Ivan?

Also, did you use the drill bit that comes w/ the kit and drill yours out?

[DELL82]

Update on problem

Well all is almost the same. Assembled the carb again. Better at idle. Went over to Stan's, he got his new carbtune unit today. Checked sync and was found very good. With colortune in we adjusted to get the blue flame. Slowely increased throttle and blue was good to 5K. Removed the carbtune unit and replaced the vacuum niples with new YAM ones Stan had. Started and the colortune was blue until 4K then went black and the #4 stopped running. Seems that when the butterflies opened it flooded.
WHAT NOW
WE HAVE TRIED ALMOST EVERYTHING. I SAY ALMOST BECAUSE THE NEXT THING MAY FIX THE CARB.
Any other suggestions will be very welcome.
Dell82

[Larrym]

Did you do the "wholesale" swap of internal carb parts between #4 and #3?

[Ivan]

I was messing with my scoot tonight and have a bit of the same problems. If the idle mix is set right, it farts and belches. For it to idle right, it needs to be rich.

Also, I had to do a pickup wire repair, so while I was in there, I bumped the timing ahead about 3 degrees, and it seemed to help. The off idle stumble is much better and it doesn't belch and fart on decel anymore. I don't have a timing light, so its anyone's guess if its right or not. There isn't enough throw to adjust it via vacuum reading, so that's out.

Anyway, all that was to say, might help to check your timing.

[DELL82]

Larrym, I did not swap parts. Could not get to #3 anyway. I could get to #1 though and might consider that one.
Ivan I don't know if I can change the timing on the XJ1100 or not will investigate, however why is #1, #2 and #3 running OK?
Dell82

[psycoreefer]

I agree with larrym, try swapping all the parts from the problem carb into another carb. That means everything, float, jets, slide and needle, emulsion tube etc. #4 to #1 would be fine. If the problem does/doesn't follow the carb internals it'll narrow the search down.

[XJOK2PLAY]

Larrym, I did not swap parts. Could not get to #3 anyway. I could get to #1 though and might consider that one.
Ivan I don't know if I can change the timing on the XJ1100 or not will investigate, however why is #1, #2 and #3 running OK?
Dell82

Hey, Dell...
From what I've found out about the XJ's timing setup, it's controlled from a small little black unit under the tank via vaccuum... that device changes voltage (potentiometer) that's sent to the TCI... the TCI then controls what /when to the coils... not sure of any way to change timing since the XJ's electronically controlled... haven't tried to physically redrill / reposition the hard mounted P/U coils either...That may or may not work to advance it.

I thought for a while my vaccuum switch had failed... could not get it to keep a consistant idle speed... get it set, ride it, it would climb through the roof. PITA! Finally, Cody & I resynched the carbs... but... we started w/ the #3, got the highest vac reading we could get, (instead of a low #, then trying to synch the other 3 to #3...) This made all the difference, and that's been the end of that problem. Bike runs so much better now. So, synch can really be a major issue... didn't know if you'd tried to get your highest reading on the first carb, then setting the others to that...
We could get all 4 synched fine at the lower vac reading... but it wasn't right, and the bike's performance sure showed it. Just a suggestion, may not be your deal... but it sure sounds like something's screwed up in that carb.
Hope ya get it figured out Dell. Say Hi to Stan for me.
HTH's.
Bob

[Ivan]

You can adjust the timing, but, I think on 80 and 81's you have to drill out the bolt heads, and replace them. I think on the 78 and 79 its just regular pan head bolts. Loosen them and rotate the pickup coil assembly. That's all it takes. I think the crappy gas around here likes a bit more advance than actual gasoline like the had in the 80s.

As far as why three would be ok and on not, sounds like you have chased down everything else, I thought it might be worth a try is all.

[jmnjrpa]

Hey Cy,

Just got around to your post.

E85 IIRC only has about 60% of the energy of straight gas, which means you would be getting around 18MPG and would have to have gone up considerably on the jets to get the right mixture since it uses a much richer mixture than normal gas. That and it's very caustic on the fuel system, which means it has to be designed for it, I don't think our carbs would last very long running E85 through them.

Now I don't have the numbers handy but you need to recheck. E85 is 15% ethanol and 85% gasoline. With that in mind and no other considerations the E85 would HAVE to have at least 85% of the power of pure gasoline. I am running 120 mains outer cylinders - 125 mains inner cylinders-4 pods - Air box gutted and 4 to two Mac turnouts. It will launch in first three gears with my fat 250# azz hanging on. I haven't checked milage but guess about 30/35 and I am heavy on it all the time. Even two up it blasts out like a rocket. One thing I do is add 1/4 cup octane booster (when I am home and think about it) because of the 87 octane they didn't even sell 30 years ago.

[Ivan]

I am pretty sure E85 is 85% ethanol and 15 % HC fuel...

[cywelchjr]

Yeah, 15% ethanol is what most of our gas has in it now. E85 is the reverse, and they are trying to get it ok'd to go to 20%. I hate to think what it's going to do to our bikes and cars not engineered for it. Not to mention the gas milage going down again, and having to rejet even for those with everything stock.

PS, I'm about to start buying race gas and diluting it a bit with regular to get it back to something worth running. Got a local station that carries it, at $6 a gallon. But it should work good.

[jmnjrpa]

My bad,

I know we are running 15% ethanol and just assumed that the E85 was the same.