[2001ex500]

I have a 2001 ex500 with 2500 miles. I just got it and apparently the last owner didn't ride it much(or at all) the last year and a half. It's in great shape but I am having a little trouble setting the idle speed. When I got it ran kind of rough, so I dumped the gas, sprayed the carbs with gumout without removing them, and am running carb cleaner in the fresh gas. In general it is running great except I am having trouble setting the idle speed properly. When I got it idled around 1500 fine for the first 20 minutes and then the idle speed slowly increased up to around 3000. I used the idle screw and pulled the idle down to 1500 hot, but now it struggles when cold and idles around 1000 for the first 20 minutes. Do these engines run cold and I just need to let it warm up for a long time? Does it sound like my idle circuit is working properly, or do I need to look at pulling the carbs for a real cleaning?

When I adjust the idle set screw, it seems like I turn it a little and not much change, a little more and not much change, a little more and it surges 500 rpm and I have to back it off. The dual carbs sure make this interesting.

Any suggestions, insight or thoughts welcome!

 

[PontiacJack]

I am not expert but had the same problem, but a little more extreme on an EX250 I was told a good carb clean and sync would do the trick...

 

[MrSciTrek]

I know that with some water cooled cars there can be problems because the thermostat is stuck open & the engine takes a long time to warm up.

Is your temp guage indicating a decent warm up?

You didn't mention using the choke (by left thumb). Is it working okay?

 

[2001ex500]

Yes, eventually it will probably come down to a clean and sync; 2500 miles doesn't seem like much but I guess all that time sitting counts too even if it's not reflected in the mileage.

Yes, the choke seems to work(it won't start without it full on). It seems a little bit touchy compared to other chokes I've used. If I even move it back a crack off full it seems to lose it's effectiveness and the rpm drops a lot. Then when I put it back to full the rpm surges high before settling down. I'm used to a more linear progression of being able to back the choke off.

It does seems to warm up by the gauge pretty well. It goes up smoothly, but even when it gets to operating temp on the gauge the idle is still low for a good while. Usually the idle doesn't go up as described until I have ridden it for a while and I come to a stop somewhere and I notice.

Thanks

 

[fog]

While I think your being overly fussy. (hey it's running ain't it?). Because of the factory settings being so lean the engine won't run steady till the manifolds all the way out to the carbs are full hot.
The fix is to inrichen the idle settings by opening the pilot screws a bit. There is plenty of info on how to in this forum.

FOG

 

[MrSciTrek]

Yes, the choke seems to work(it won't start without it full on). It seems a little bit touchy compared to other chokes I've used. If I even move it back a crack off full it seems to lose it's effectiveness and the rpm drops a lot. Then when I put it back to full the rpm surges high before settling down. I'm used to a more linear progression of being able to back the choke off.

That's the way my '05's choke is too. Sometime when taking a closer look at it, maybe it'll become apparent why the choke works that way.

Shots in the dark....
Is there any chance that there's a loose bolt on the carbs somewhere allowing air to leak in... maybe only when it's warmed up & the metals have expanded?
Or maybe something is twisting, pressing against the choke cable when the bike gets warm or has bounced around a bit?
Maybe there's a sticky float or float needle valve (fuel inlet)?

 

[ex500az]

Stupid Question, but what should the rpm be at idle.

At 1,000 ft. here in Phoenix my bike is at 1,300 up north at 6500 feet it is at 1,100 which I understand why. but the shifting seems better at the 1,100 rpm.

Where should it be?

Thanks for replies

 

[2001ex500]

While I think your being overly fussy. (hey it's running ain't it?). Because of the factory settings being so lean the engine won't run steady till the manifolds all the way out to the carbs are full hot.
The fix is to inrichen the idle settings by opening the pilot screws a bit. There is plenty of info on how to in this forum.

FOG

My intent is certainly not to be fussy. Having never dealt with a dual- carberated engine before I'm trying to see what is normal and what can be corrected. As you say, it's running, and it runs great (in my opionion) out on the road. These are minor issues, but all the same, if I can improve them then I like to try. I'll try making it a little richer and see if that helps.

Thanks

 

[AudrEEz]

While I think your being overly fussy. (hey it's running ain't it?). Because of the factory settings being so lean the engine won't run steady till the manifolds all the way out to the carbs are full hot.
The fix is to inrichen the idle settings by opening the pilot screws a bit. There is plenty of info on how to in this forum.

FOG

My intent is certainly not to be fussy. Having never dealt with a dual- carberated engine before I'm trying to see what is normal and what can be corrected. As you say, it's running, and it runs great (in my opionion) out on the road. These are minor issues, but all the same, if I can improve them then I like to try. I'll try making it a little richer and see if that helps.

Thanks

i had the same problem like you, i ended up taking FOG's advise to pull the carbs, clean the pilot jets till you can see the light thru them, richen the mixture (2.5 turns) and adjust floaters to 17mm. all that gave me nice smooth idle and no flat spots, no more higher rpms when engine is warm, mileage increased from 150miles per tank to 200. and i'v been riding without any problems for about 2000 miles since then. and i forgot to thank FOG an everybody else for nice DIY writeups. Thanks!

AJ

 

[2001ex500]

Yes, that sounds like good advice to me. I'm just having too much fun riding this thing to take it apart yet. It's supposed to get cold next week...

Thanks to everyone for all the help!

 

[dansdad]

are there directions on here on how to adjust the pilot screws or take the carbs out?