Finally figured out why my kz 400 bobber run's bad

The carb holders are often the problem but just as often they are not suspected because the part you can see looks fine. I had this problem several years ago with mine, and even though the rubber I could see looked (and was) perfect the rubber mating surface that seals against the cylinder head had tiny little cracks that couldn't be seen until removed from the engine. A guy showed me the carb cleaner trick (engine died immediately) which demonstrated that those itty bitty cracks were leaking bigtime. Holders replaced - problem gone!

Old Man Rock wrote:

Pretty amazing what a small vacuum leak and a clogged jet can cause in performance & troubleshooting frustrations....

Now that I'm thinking about it, your posting (fixes & results) would help at least 10 of the carb postings recently put on the forum...

You reviewed & analyzed the situation and symptoms, tore into the carbs and cleaned them up, asked intelligent questions, listened to the advice provided and did accomplish the recommendations and low & behold, "hauls ass".....

Have to love it!

Way to go young man,

OMR

Thank's OMR, it feels good to actually ride this thing and not worrying about everybody else passing me because its only hitting on 1 cylinder.

650ed wrote:

The carb holders are often the problem but just as often they are not suspected because the part you can see looks fine. I had this problem several years ago with mine, and even though the rubber I could see looked (and was) perfect the rubber mating surface that seals against the cylinder head had tiny little cracks that couldn't be seen until removed from the engine. A guy showed me the carb cleaner trick (engine died immediately) which demonstrated that those itty bitty cracks were leaking bigtime. Holders replaced - problem gone!

Ya, mine looked fine on the outside also, but when i sprayed carb cleander on them and it diewd i knew that was a major part of my problem.

Ok so now that i can ride this bike a fair distance, i figured i would give it its first real shake down run. I suited up and headed out, it ran awsome up until i stopped for gas. I went to start it, but it would fire over and as soon as i sat on the seat it would die. Turns out the power wire goint to the coil was loose and came out completley. I fixed it and it fired right up, and rode flawless the rest of the way. I am however going to change the exhaust, from drag pipes, back to the stock head pipes and mac slip on mufflers. Hopefully this will make it run smoother, and the nieghbors won't give me a dirty look when i ride by:laugh: :laugh: :laugh: