newbie needs help..

Hi guys.. sorry to bug.. im new to this bike.. its a 82 yamaha midnight maxim 750... i got it used sat for a few years.. i cleaned the dust off poped in a batt some fresh gas and she fires... BUT....only runs on 2 cylinders.. not sure fireing order... but if ur standing infront of bike looking at it the 2 that work are on your left side.. the other 2 dont... so iv checked.. theres spark and gas in all 4... the 2 that dont fire are just soaked.... but they do have spark.... what should i look at next... is a float maby stuck and allowing to much gas???

 

Check plug caps unthread cut a little off ends with side cuts rethread onto plug wire, check plug gap too ..simple first.

 

Begin with reading.

The Information Overload Hour

TECH TOPIC: The Real Costs of Maintenance

IN THE CHURCH OF CLEAN

 

Possible that the two non-running cylinders are victims of gummed up carbs. Definitely take all four carbs to church (of clean) and replace all seals/o-ring, to include shaft seals.

 

Similar to what wink said: clean carbs. I had a lawnmower that wouldn't start at all but once the carbs were de-gunked it ran like a champ.

 

hi i have a 83 750 midnight maxim that is running rich i think. pics below.... so my issue is wont idel till warm once running works great till 5000ish rpm then lags then passes 6000ish rpm then goes like a bat outa hell while blowing thick black soot. iv had carbs soposedly cleaned at a shop wich made bike run better but plugs still black and still soot comming out exhaust at wide open. my exhaust is stock minus the h pipe rotted so i just created my own 2 into 1. no gas on air filter (filter brand new stock) but bike smells of gas. what can i look at to adjust cause im not paying no one this time il learn how.... with your help lol...i ride the bike every day . each morning i clean plugs come home from work and coverd in black soot... any info and advise would be great thanks. and the black soot out the exhaust is a new thing is it just ckeaning itself out??

 

btw i ment to say only blows black soot at full throttle

 

Merging with your exising thread.

Did you clean the carbs as was suggested earlier?
If so, how did you clean them?

 

i ended up taking the bike to a bike shop and they cleaned them put new plugs plug caps and a filter said no vaccum leaks but bike still acting up. im not sure what they did for cleaning but i paid almost 300$ so i hope they did it right

 

They didn't.
Sorry, but it's true.

You need to do this yourself in order to get it right.
IN THE CHURCH OF CLEAN

I'd start with getting some clear tubing and checking the fuel levels in the float bowls. Too high and she'll run rich. Also take a small screwdriver and check the settings on the idle mixure screws. Turn them closkwise slowly until they just stop (do NOT tighten them). Count the turns. It should take between 2.5 and 2.75 turns. If it's more than that, reset them to 2.5 turns out.

 

how does clear tubing help me see if too much fuel in bowls... im like 100% new so i don't understand. do i measure how much comes out of them?

 

Setting the fuel levels

You'll just be checking levels with the carbs on the bike.