running awful!!!

Need some help, I have painfully resurrected this beast.
However every time it appears have made progress, The bike decides I haven't, I have cleaned the carbs, synced, new plugs,oils,fluids braks vaccum hoses you name it! 1 day runs good other not so.
starts great, some times a struggle big struggle. Symptoms: runs like its on 3 cylinders, ironicly #3 is the problem at idle #3 exhaust pipe lot cooler then others, after I rev it to wind it up comes to life. However not enough power and to do speed limit almost full throttle. went on 30 mile adventure today wasn't a good one. I'm not sure what is going 3 days ago it scared me! now I felt I should help it by pushing. I am very familiar wth this bike's parts & function, but im just thoroughly getting to the point of sending it off a cliff!!!!!!!!!!
HELP! please

 

I'm sure you checked the valves right??

 

Yes I did, I forgot to mention the backfiring that follows out of right pipe. like a timing issue or electrical but all is working.

 

now this thing wont get out of its own way, when I know this bike is monster

 

Also rpms limited as well not like they should be or have.

 

First thing that comes to mind is the fuel to air mixture. I'm still a rookie with this so go easy if I'm wrong but my thought process is if your getting low firing on 3 I'm thinking too rich. When you tuned your carbs did you colortune? Also how old are your spark plug caps? Maybe they are worn out. Also what about cylinder compression ? My first approach would be the mixture .

 

I had checked comp valves whole 9 exception of color tuning ,wont be harsh never hurts to go over, look for obvious, im not perfect, auto mechanical background I do have went thru all wires, air mixture is symptomatic of it but idle not firing on 4 till I get the engine in the 4000 rpm area. Then all fire, plug wires very possible likely the cause, now how do I replace end going into coil? And can you? Have a new set. not able to find this information anywhere, honestly havent looked hard but anyone can save me hpurs of research please you will forever be my hero.

 

Backfiring (really afterfiring) on declaration? If so that points to being lean on #3. Have you checked for air leaks? What did you set the idle air screws to for your baseline?

EDIT: juat saw your last post. By not firing on #4 do you mean no spark or just no flame? If it's spark but no flame then the most likely cause is a plugged idle passage.

The plug wires are moulded into the coil. They can be cut back and spliced, or if you are willing to do some surgery on the coil cases they can be replaced. New aftermarket coils are avalible though, and that will allow you to use all new plug wires as well.

At this point I'll sugggest that you don't jump from one system to another. Get the electrical sorted. It sounds like you are on the right track, so save my advice above the edit for later.

 

Big moe after fire correct producing misfire then back fire, set mixture screws at 2 7/8 turns for age and plugs look good, not lean not rich, when I hold my over #3 air inlet seems that Im not getting all of the vaccum I should like I do off others so could be vaccum only seals not changed were throttle shaft seals , bit wouldnt it still fire on 4 at idle?and would leak at throttle seal give me the 60 percent power reduction im experiencing ? Were getting some where

 

Cyln 3, I've found the weak wire for ignition in wire harness electrical is sorted, and idle passage is clear I checked thought same, seems like its dumping fuel in as well not lack of.

 

Side note for site administrator, after what I've been thru with this bike I deserve 2nd if not 3rd gear I just saying, bike was put in the oh well corner in 06 till Iunearthed it in march this year. A feat in itself.

 

OK you mentioned 4 picks up at 4000. That sounds like its at The point when you bypass the mixture part. Honestly I think you need to adjust that mixture. I personally would balance carbs, then colortune ,then balance, colortune, and finally balance. That's my best guess. Everything you've said points to that . with the sparkplug caps you can change just the ends. I cut mine right above the old one and screwed on the new one.

 

I have color tuned several times, I have learned to do everything 5 times on this bike, on 1 2and4 blue 3 was orange, I tune this hot after a ride being under load helps with better tuning, like a woman this bike is moody!

 

You want blue with a bit orange as these bikes like to run a touch rich. Have you done a plug drop?

 

Hmmm. Some thoughts, in no particular order: Exhaust leak, cracked intake boot, burnt valve, missing or damaged pilot air o-ring, carbon deposits causing a valve to not seat fully.

 

check your airbox boots to make sure that all the
clamps are tight
I had one loose and just hanging on my bike
it ran like crap
tightened the clamp and it was back to good
also with the airbox clamp loose all plugs were tan

 

It may need throttle shaft seals. Were the carbs submerged in anything without being fully (throttle shafts and butterflies out) disassembled?

Did you accurately wet-set the float levels?

 

Ok found the problem was a screwy plug wire with a couple of fouled plugs, now this bike is the way she should be scary fast, I do love tinkering on things but surely nice to just ride for a change
Thanks to all who provieded info and ideas with out you all wouldnt be where I am with this bike.

 

Yeah, Do a compression test and let us know the numbers......

Dave

 

133,135,137,135 cylinders in order of 1 to 4 was first thing I had done before placing a dime into the bike.

 

That looks good...... So we can rule that out---

 

I did the post above refers to finding 2 fouled plugs and some messed up plug wires, operated with success, previous owner had the wrong pilot jets, and the enrichment circuits were plugged, along with all the o rings that were rotten, throttle shaft seals as well, I have painfully spent back breaking hours in learning this bike and undoing what old man did. But it was worth it tho.