runs crap wn hot

indymorg · Post by **indymorg** » Fri Aug 06, 2004 3:55 pm

has any 1 any ideas when my 89 exup 1000 gets hot in traffic the throttle response is crap. its hard to pull off at any pace, 2up its dangerous.get a bit of open road ands it starts to cool it comes back on line carbs have been set although it has done 48000 miles so they could be worn cheers

Post by **jjs777** » Fri Aug 06, 2004 6:02 pm

Is the fan indeed coming on at all? Have you double checked the radiator fluid? The bike is now 14 years old - is it possible that the radiator is blocked internally ? With the left rear cowl off, have you checked that the exup valve motor is indeed able to turn and cycle when turning the bike off/on ? -John

dragracer1951 · Post by **dragracer1951** » Fri Aug 06, 2004 9:15 pm

Classic rich symptoms Have a look at the emulsion tubes. Jet kit? do a search...lots of ideas been discussed on this subject J

indymorg · Post by **indymorg** » Tue Aug 10, 2004 2:39 pm

yes the fan works and yes the exup valve works so i think the over rich is the way to go cheers

flyingcircus68 · Post by **flyingcircus68** » Sun Aug 29, 2004 7:31 am

If your having a problem with consistent idle and off idle stumble when it's hot, then your problem might be either rich mixture as dragracer mentioned, or it can be the valve seals. The mileage you listed on your post is high enough to suspect worn valve seals. Check your plugs. See if they have an oily deposit on the threads. How is the porcelain? It should be white. Have someone ride behind you while you wind it up in second gear to 6k, or so, chop the throttle, then quickly apply throttle. If you see blue smoke, its either the rings, or valve seals. If it runs good on cold days, it's probably worn valve seals. The seals are made of a green polymer which I suspect is viton. If your seals are worn, they will work marginally when it's cold, but as they heat up they grow and get softer. When they stop hugging the stem, high vacuum conditions such as idle, coast down and max power suck oil past the valve stem. I've collected 87k on my odometer and the hot idle/off idle had become enough of a problem that I recently replaced the seals (2nd set). I made my own spring compressor tool that allowed me to do the work with the head on the bike. I went out on a 90 deg. day and I let it idle until the fan cycled. I purposely stuck myself in traffic to see how it would run. I had no problem. Even after extensive idling, it pulls away cleanly. It happily pulls away with no throttle at all. If anyone is looking to swap out the seals without removing the head, I could send you a drawing of the spring compressor tool.

flyingcircus68 · Post by **flyingcircus68** » Sun Aug 29, 2004 11:40 am

I forgot to add the following tidbit: When checking the plug color, look for a little deposit staining the porcelain tip. If this deposit is only on one side of the porcelain and the opposite side is white, you might have valve seals that decided to retire. The deposit is from the oil that is being sprayed on it during the intake cycle. The porcelain is made to run hot, so it bakes on instantly. Well that's it, time to head out and enjoy the blast of hot air from the cooling fan. <img src=http://img.photobucket.com/albums/v209/ ... iker_3.gif ALT=":riding">

indymorg · Post by **indymorg** » Sun Aug 29, 2004 12:47 pm

thanks for that do u think that it might be why the slides in my carbs do not begin to lift until about 3500 be cause of the lose in vacuum ? not noticed any smoke but would definitely like the plans fore the valve comp cheeres

flyingcircus68 · Post by **flyingcircus68** » Sun Aug 29, 2004 6:47 pm

No, the vacuum leak from worn seals would not be enough to cause a vacuum loss and should not have any appreciable affect on part throttle running. You should not expect your slides to oscillate at idle or off idle. I don't have an exact rpm for you to pinpoint when they should be called into action, but it really depends on air demand. 3500 rpm is in the neighborhood of what I would expect the slides to start jumping around.

indymorg · Post by **indymorg** » Mon Aug 30, 2004 3:18 pm

ok thanks for that its put my mind at rest a bit it must be mainly using someother jet then below 3500 if so people are saying drop the needle down a notch but this would not help, because that would only take affect after 3500 ?

flyingcircus68 · Post by **flyingcircus68** » Mon Aug 30, 2004 3:26 pm

You're suspicions are correct. that rpm is mainly controlled by the pilot jet circuit. These can be changed out also, but in most cases you wouldn't have. Change them only after you're sure about the main jet/jet needle combo.

dvsfzr1000 · Post by **dvsfzr1000** » Wed Sep 08, 2004 1:56 am

I had the same problem with my bike and it was because the valves were so badly out of adjustment that a feeler gauge(way smaller than spec) wouldn't even fit between the bucket and cam base circle. The intake valves weren't closing all the way when hot.

flyingcircus68 · Post by **flyingcircus68** » Wed Sep 08, 2004 6:07 am

Good call dvs, Valve clearance can be a culprit and probably should be checked first. <img src=http://img.photobucket.com/albums/v209/ ... Cheers.gif ALT=":cheers">

flyingcircus68 · Post by **flyingcircus68** » Fri Sep 10, 2004 6:15 am

Indy, I could send you a pdf of the tool via email. I don't have a personal website, so I can't post it there. I'm too ignorant to know if there is any other way.

indymorg · Post by **indymorg** » Sun Oct 10, 2004 12:55 pm

hi sorry its been a while but i have had a career change and been really busy so u will need my e mail then yes ? one thing i did have time to do recently i dropped the needles 1 groove its really improved the bottom end but the middle where it was strong is now not so good. but at least it shows it must be to rich at the idle to 4 thousand. maybe if i put the the needles back and turn the mixture down a turn ?

flyingcircus68 · Post by **flyingcircus68** » Mon Oct 11, 2004 9:58 am

If you're burning oil, leaning will help keep the plugs clean, but that is not the solution. Check your plug threads. if they are oily, fix that problem first. If not, then it's probably a jetting problem and you could play with the pilot jet or fuel level to lean out off idle.

Androooooo · Post by **Androooooo** » Tue Oct 12, 2004 6:35 am

just wondering, at what temperature should the cooling fan come on? if it isnt coming on, what is the likely cause? thanks guys, Andrew 1997 yamaha yzf600r

Post by **FZRDude** » Tue Oct 12, 2004 11:25 am

Either 100 C or 103 C. I don't recall. Tim <img src="http://img.photobucket.com/albums/v209/ ...  Insert Joke Here Dir. of Entertainment<a href="http://eddieandthecruisersmc.com" target="top"> Eddie & the Cruisers</a> '94 FZR 1000

indymorg · Post by **indymorg** » Sat Oct 23, 2004 10:55 am

there is no oil on the threads . but the porcelain was black is in to weaken? i think it is

flyingcircus68 · Post by **flyingcircus68** » Sun Oct 24, 2004 5:13 pm

Before you fiddle with the mixture, verify that it's not another problem. valve clearance, ignition system, emulsion tubes, float height, etc. There is plenty of info in related threads, so read and investigate.

EXUP Worldwide

runs crap wn hot

runs crap wn hot

Re: runs crap wn hot

Carbs

rich

Re: rich

Re: rich

valve comp

Re: valve comp

carbs

Re: carbs

When was the last time your valves were adjusted?

Re: When was the last time your valves were adjusted?

Re: When was the last time your valves were adjusted?

needles

Re: needles

cooling fan

Re: cooling fan

c

Re: c