EXUP Worldwide

long story short, i tried and faild on fixing my exup so it would run right. carb's issue.
well i bought a "new" set of carbs of a 95, that was cleaned and set up right as everything was suppose to be, and ofcourse hope it would stop my problems on the bike running.
only thing i havent done is trying to sync em as im waiting for my new sync tool to arrive some times next week( i hope). been searching and reading up on the troubble im getting with it, so here it goes, it starts up fine everything seems and sound normal when cold on idle as it starts warming up and giving it some revs it hangs a sec or to before running down to idle and the idle is rough, when warm. i tried last night to take it for a spinn down the road it does not give me any power to speak about like it's running on 3 out of the 4 cylinder's that it got. and when it's hot it starts to missfire and u get some rattle in the engine.
it was alot worse on my other oem carbs that i took of cos i think i messed em up bad, im clue less atm, tried to make a video of the bike running
but there is no sound on it, gona do another one.

what ive done is this, ive put brand new ngk spark pluggs in, cut down the spark plug wires to get a good conection. some where loose on the wires\leds, valves was done before this and i hope it was done right since i have no troubble starting the bike, and since it runs ok when cold im wondering what could be wrong, cdi? coils? carbs? me? ive almost given up on the bike and been actually thinking of start selling it of in bits if i cant get it to run againe, next year i willl take it to a shop if cant figure it out as the seson for driving is soon to be over
and it's kinda hard to write up on how it's running to expalin it. but since ive change the carbs it cant be the carbs thats the troubble, or it can be i have no clue really.im pissed of at it.

it's running rich on the bottolm look at two things. egg shaped emulsion tubes, and the pilot air screws. If the tubes are fine. turn the screws in a quarter turn at a time till it acts right.

i will look into it. the srews ar atm set at 2 and 3/4 turns out and the jets are all stock no jet kit in em

Hey Peppa2

You said you changed the plugs, did you also check the plug cap resistance. It sounds to me as if you have a bad plug cap. Make sure you get someone to tap on the thing as you're testing it with a multimeter for resistance. If they are bad and you're wanting to replace them. DO NOT use NGK Plug caps. They have almost near half the resistance in them and for some reason the Yamaha ones work marketably better. Electrically, these engines are very fussy pricks! I realize the NGK's are 'bout a quarter the price of the Yamaha sku but hey, it's your bike and you do what you wanna do. Apparently somebody has suggested you can find NGK caps with near the same resistance as the Yamaha ones but, I've never seen them. I also suppose you could replace the bumb resistor but there again, I've never been able to find the same type of replacment resistor at an electrical shop.

I'm not sure I'd suspect spark to be the main issue also and you may also have a fueling issue as well as Jim has suggested.

Have fun.

i have tested 2 of the caps and they was reading out about 8.4 ohm or what ever it's called the book ses 9-12 is good so i might just need to get sme new down the road,

8.4kohm should be close enough to 9, what you don't want to see is 0 or infinite. Sounds like emulsion tubes to me.

All you need is one bad cap to foul riding significantly. Did you also beat on the thing while testing it. Wouldn't hurt to warm them up before testing also. Needle Jets will in no way cause the kinds of problems you are talking about to the degree of severity you are describing. I would be suspect bad spark somewhere!

Needle Jets (a.k.a. emulsion tubes) will in no way cause the kinds of problems you are talking about to the degree of severity you are describing.

Not unless they were really worn out, and mine were, and these are the exact symptoms I had; so bad that after 150kms, a new spark plug would foul up and misfire and the bike then ran on 3 cylinders no matter what!

Valve clearances set wrong!!!!!!!!!!!!!!!!!!!!!!!!!!

Check them first, all manner of issues especially when it gets warm!
Blow back into air-box from partially open valve will cause your problem.

Regards
Ozzyfzr

Peppa2 wrote:long story short, i tried and faild on fixing my exup so it would run right. carb's issue.
well i bought a "new" set of carbs of a 95, that was cleaned and set up right as everything was suppose to be, and ofcourse hope it would stop my problems on the bike running.
only thing i havent done is trying to sync em as im waiting for my new sync tool to arrive some times next week( i hope). been searching and reading up on the troubble im getting with it, so here it goes, it starts up fine everything seems and sound normal when cold on idle as it starts warming up and giving it some revs it hangs a sec or to before running down to idle and the idle is rough, when warm. i tried last night to take it for a spinn down the road it does not give me any power to speak about like it's running on 3 out of the 4 cylinder's that it got. and when it's hot it starts to missfire and u get some rattle in the engine.
it was alot worse on my other oem carbs that i took of cos i think i messed em up bad, im clue less atm, tried to make a video of the bike running
but there is no sound on it, gona do another one.

what ive done is this, ive put brand new ngk spark pluggs in, cut down the spark plug wires to get a good conection. some where loose on the wires\leds, valves was done before this and i hope it was done right since i have no troubble starting the bike, and since it runs ok when cold im wondering what could be wrong, cdi? coils? carbs? me? ive almost given up on the bike and been actually thinking of start selling it of in bits if i cant get it to run againe, next year i willl take it to a shop if cant figure it out as the seson for driving is soon to be over
and it's kinda hard to write up on how it's running to expalin it. but since ive change the carbs it cant be the carbs thats the troubble, or it can be i have no clue really.im pissed of at it.

The items above in bold would allude to a lean condition. What did you set the float height to?

14mm

Hmm, how do the plugs look? Got any pics? Have you physically checked for a good, bright blue spark?

plugs are brand new have run on gas for 10 mins max. the old ones taken out was black on the tip of the plug and some grey, as far as i know black/sot on plugs comes from to mutch fuel

W/O pics, which of the plugs on the following page looks most like yours?

http://www.dansmc.com/Spark_Plugs/Spark ... talog.html

If the porcelain is gray I would still lean towards lean.

ok i got 3 plugs looking like nr 11 and i got 1 looking like nr 3 and that one looking like nr 3 is used to be in the number 3 cylinder and under all my plug changes think i done it 3 times it has look like that pic nr 3,

Nice find on that chart, Apex.