High idle..throttle hang

[kinger]

Just got the engine installed and it runs real good. It will idle all day long at what ever RPM I set it at however when I blip the throttle it will not come back to idle immediatly unless I set the idle to 900 rpm then it comes back so fast it almost kills but doesn't. When I set it to 1300 blip the throttle it will hang there, putting the choke on INCREASES the rpm not decreases.

The carbs were cleaned before they went on, the plugs are brand new CR10EK.

I only put a mile on it so I will keep fiddling. Searhcing some guys found a TPS problems, other found a sync problem, nto sure what i have here unless the pilots immediatly plugged up again??

Thanks

 

[SnoWarrior]

Hey Kinger, I have the same problem.
I took the carbs off a second time and cleaned, checked everything. I even replaced 2 orings on the mains that were a little chaffed.
Still same thing. I can get it to idle at about 1000, but wants to stall. I synced the carbs and the vacuum seemed fine.
If I choke it, it will run up to 5000 rpm, like using the throttle.
I have double checked the vacuum lines, all of them. I checked the boots, even sprayed water with a spray bottle on everything while running, to check vacuum leaks. No change with water. I am starting to get baffled here, was ok last season.
I rode the sled and it ran fine. Pulled max rpm and ran smooth. Just have to get this figured out, not good with the choke thing.
My pilots are 2 turns out.
Seems like it is lean.
Keep me posted.

 

[SnoWarrior]

Update, just checked my TPS. It is reading 1K ohms with no throttle. It is suppose to be 0 to 4K ohms from 0 to full throttle. Looks like that is the problem....I hope. It is too cold to fool with it now. I will hook a power supply up to it tomorrow and see if I can adjust it.


BTW the ZX2 really rocks

 

[kinger]

Great I will check the TPS as well and see if that might be my issue. I'm hoping so as that is easy to replace vs taking the carbs back off AGAIN.

 

[RedRocket]

putting the choke on INCREASES the rpm not decreases.

That's because it's not a choke, it's an "enricher" and just adds fuel for a cold start rather than cutting air like an old choke.

It sounds like your TPS...

 

[kinger]

Just checked the TPS and it tested out to spec:

5K ohms with a spec of 4-6

.98-3.99 ohms with a spec of 0-4

Any other thoughts?

 

[SnoWarrior]

It is suppose to be 0 ohms with no throttle between yellow and black (looks like you have about the asme reading as I do) Then should go to 4K ohms when you pin it. Should climb slowly as you press throttle., then come back to 0 ohms. To adjust you can use 3 1.5v batteries and a meter, about 5 volts dc. (I will use an external power supply. Will let you know tomorrow, as we are getting a nast ice storm now.

 

[kinger]

Jerry it actually i ssupposed to read .71 at no throttle, and climb from there. I found a like while searching about it. Ted Jannetty posted about it.

 

[kinger]

I think I will jsut pull the rack and clean it again, I just installed the gas tank and it may have loosened up some crap at the bottom of the tank and plugged them again. I hate these small azz pilot jets!!

Wish we could get a better fuel filter that would filter out the stuff that plugs these jets.

 

[RedRocket]

Jerry's got it right, 0-4k ohms between Yellow and Black, 4-6k Ohms between Blue and Black.

Here are the pages right out of the service manual:


Click thumbnails for larger images.

Don't believe everything you read on the internet...

 

[kinger]

I took the carbs apart and ALL of the pilots were plugged or partialy plugged! Plus two of the secondary jets were gummed up to!

I hate these small pilots!! Luckily I have it down to about 40 minutes start to finish

 

[SnoWarrior]

Yea you are right kinger. Reads .68 volts dc to 3.77 at wot. I forgot that it reads where the idle screw is at rest. Well guess I will pull them again.

 

[kinger]

Yep, RedRocket don't belive everything in the service manual, LOL

Pulling the carbs is a PITA but I did do it in 35 mins so I guess its not a time consumer. I'm going to add external fuel filters just before the fuel pumps and see if I can get away from doing this from now on.

 

[SnoWarrior]

Shame on me...it was the pilot jets, had varnish in them from summer. Had to soak them, and run a wire thru them to get the gunk out.

I have tried stabil and seafoam. If there is any gas left in the bowls or carbs, it will gum up fast from the ethonol in the gas. I don't think the filters will do anything to stop the gas going bad.

I run marvel mystery oil thru my carbs on the Yamaha outboards I have then drain the bowls. No problem from season to season. Will have to try that with the sled in the spring. Thanks for everyones help.

 

[kinger]

Mine plugged the second time after only 6 minutes on the first cleaning. I'm thinking I may have gunk in the tank but will look tonight. It did sit about 3 weeks inbetween though, wouldn't think they would gum up that bad just sitting there with no gas in them.