First off I want to say thanks for all the great info I have gotten on hear. I am working on a 1990 Ninja 750 I bought used. it has 29000 thousand miles on it but is in awesome shape. I am having a problem running along at slow speeds 20 to 30 miles an hour in all gears it seems the engine is chugging or maybe a slight miss also does not want to go back to idle right away takes a few seconds. it doesn't want to run cold except with the choke but when warmed up it idles smooth and top end power is great runs down the freeway good no miss or anything. The only mod I know of is a Muzzy slip on which was on the bike when I got it any help would be great

 

How are the spark pugs. And sounds like your pilot jets are clooged. Have you taken apart the carbs and cleaned them.

 

I know what you mean man.. I've got the same bike.. I don't seem for have a problem at low speeds, but what rpm are you running at? if you're running at low rpms, say anywhere below 3.5k, it's not going to have a lot of power. It's always going to bogg a little bit if you try to hit it hard at low engine rpm, that's why there's all the high-end power. and it's never going to run as well cold as it will warm.. remember, that's why there is a choke.
Mine too has a tendency to stay around 3-4k rpms when i let off the throttle, but i just set my idle speed a little lower than normal, and it doesn't happen all too much anymore. i know that isn't a problem cause by clogged jets, because i spent a long time cleaning mine recently,and it still happened. but still, take off the carbs and clean every piece maticulously if you haven't already done so.
a good tune up will help a lot. You say you're running with a slip on Muzzy exhaust? do the tune up, run the bike for a while and check the condition of the new plugs. if they're dry or white, you're running lean and need to upgrade the jets if you plan to keep the exhaust.

 

good point, if your in the wrong gear and the r's are to low your not going to move very well. Tell us where you are shifting, what rpm and what gear.

 

on my7, once i did float bowl it runs gr8 at WOT but runs like **** the rest of the time. Im considering reversing it

 

plugs and filter are new also just cleaned the carbs I did think that could be a problem but it didn't help at all plugs look to be burning good maybe just a little dark so it is not running lean also checked the charging system and battery both are good

 

I just had very similar problem....and it was the Carb boots...The rubber boots were dry rotted and was sucking too much air. around the filter no less...Replaced them yesterday and now she runs like a brand new one again..

On your throttle sticking, mine did that too...real dry and dusty here, so it's easy for stuff to get gummed up....While I had air box off, went ahead and pulled carbs and did a thorough cleaning..inside and out...After re assembly, no more throttle sticking...I bet if you had a good carb cleaning, double check the carb boots, it'll be back to where she should be..

 

thanks for your info carbs were just cleaned also checked for leaks used starting fluid while engine was running, not the best idea I know, and everything seems to be sealed don't think the carbs need synced because it runs great at speed and idles great.

 

That model was a huge hit with the performance crowd.There is a possibility you have a set of aftermarket cams in the bike.I have a set in my 94 and you can forget about any response or power below 4000 rpm's.

 

Carbs should sync should be done every 5k, if you do not have the meter to preforme this most shops will charge 40.00 to do it.