2002 Resonse w/ 18hp Vanguard won't idle down and needs choke to idle (nikki carb)

[spikedbat]

I have a 2002 Response that I just bought.. This thing has the most bad gas I have ever seen before... anyhow long story short, i removed the carb and intake and soaked both in parts cleaner for days.. bought carb rebuild kit etc.

The carb in this machine is the nikki carb single barrel.
Engine code # 350447 type 1025-A1 code95072511
before doing this it would not run with the carb, only way I could get the engine to run was to spray fuel down the carbs throat.

After performing the rebuild it now starts and runs (only while holding the choke on). You can throttle the engine up and get it to drive and everything but I constantly have to grab the choke and pull it on before the engine dies down..
It idles around 2200rpm right now.. way too high as the machine just wants to take off on me when in gear.

Any suggestions on how to fix this? I read in the manual the idle adjustment screw should be set at 1-1/4 turns. I have tried many different settings.

Feeling pretty beat right now by this whole situation as I have had this machine for over a month and havnt taken it past the end of my driveway.

Anybody have nikki carb for sale or have a good idea to fix this? Worst part about it is the rebuild kit costed me $90CAN and didnt fix the problem.

[trevorakm1]

Mke sure the jets in carb are cleaned well. Set the mixture by the 1.25 turn to get you in the ballpark. Now set Idle down to where it's low but not to low and fine tune the mixture. You may have to play with it a little bit but works for me. Once set you shouldn't need the choke to shift or anything but help start. You may find that the fuel mixture may need to be varied at times due to heat in the engine compartment, I believe the heat is affecting the the fuel air mixture. I know the lboys running down south like Texas at time take the hood off to help with cooling. Noel Woods is also in line with this fuel air mixture and high heat effect may want to discuss with him, when you get to that point.
Trevor

[ARGOJIM]

I would start by turning the idle screw out so it will idle down, believe you may have misread the instructions and should have read " turn idle mixture screw out 1-1/4 turns" that screw on your response should have a black plastic cap on it now and limited 90degree rotation.
If it then idles slower with the choke still applied, open the carb back up and reclean all the ports and the metering tube. If you haven't replaced the fuel line yet at least do the short piece from the fuel pump to the carb and from filter to the fuel pump as it is probably breaking down if the gas is that bad.

Try that and let us know how you make out.

You only have to remove the top of the carb and not the whole carb to reclean with good carb cleaner and air, also remove the drain plug on front of carb where main jet is.

[Tomo]

hi
Go to the links section and look for the engine manuals . Make sure u have a clean fuel system tank, lines, filter ,carby etc .
Adjust governor as per book [u will need an infared tacho ] This will involve bending some of the linkages to obtain certain rpms . If this is wrong the rpms will rise then fall or just stay reving . This must be checked to insure proper reliable operation .

tomo

[spikedbat]

Ok guys you were right it was dirty slow speed jet.
Not sure how it got so bad as I had already had this apart and cleaned it up once before.

After seeing how much green gunk had gotten in there it motivated me to just remove all the fuel lines and replace them all with new as I had a roll handy.

So problem is now fixed and the machine idles without the choke. I have it idling around 1300rpm. Does anybody know what the actual idle speed should be for the 18hp Vanguard? In the manual it's saying the idle rpm is determined by the spring colour of the governor. I see green paint on mine, but the manual is only talking about white and red from what I remember..

Another problem is that even though now it is idling, the primary clutch is still driving the secondary, in other words the belt is not adjusted properly to slip on the drive clutch or the idle is too fast and causing the clutches to engage... I can stop the driven clutch with my foot and then the belt will slip as intended. I'm sure this is a common problem, should I look to adjust the driven (secondary clutch belt height) or should I be looking to drop my idle down even lower??

Thanks again for the help guys! Great forum going on over here.

I would start by turning the idle screw out so it will idle down, believe you may have misread the instructions and should have read " turn idle mixture screw out 1-1/4 turns" that screw on your response should have a black plastic cap on it now and limited 90degree rotation.
If it then idles slower with the choke still applied, open the carb back up and reclean all the ports and the metering tube. If you haven't replaced the fuel line yet at least do the short piece from the fuel pump to the carb and from filter to the fuel pump as it is probably breaking down if the gas is that bad.

Try that and let us know how you make out.

You only have to remove the top of the carb and not the whole carb to reclean with good carb cleaner and air, also remove the drain plug on front of carb where main jet is.

[ARGOJIM]

Drop the idle lower, if the screw will not do it you may have to bend the governor linkage as per the B&S manual to govern the idle(force it lower). The green spring is used on our vehicles.

[spikedbat]

Drop the idle lower, if the screw will not do it you may have to bend the governor linkage as per the B&S manual to govern the idle(force it lower). The green spring is used on our vehicles.

Yeah the idle screw is all the way out. It's not going to lower the idle anymore.

What rpm should I be looking for? Why does the manual mention spring colours that we dont have?

Any advice on what direction to bend the governor?

[Tomo]

HI
down load the manual
Recommended u check the governor shaft to linkage clamp
The vanny twins have a governed idle
Idle at 900 -1100
The main spring also has 2 positions 1 for generators and 1 for everything else also.

tomo

[spikedbat]

I have the manual, I'll have to focus more clearly on messing with the governor.

However I did remove the valve covers and found that both intake push rods were not seated properly in the middle of the rockers. Looks like they (both cyl) had jumped out and were sitting off to the side.

Is that a common problem on these engines? How would have that occured?? Once I moved them back into position the clearance was 0.15. I didnt get to run it after finding this as it was late but i'm hoping that explains the lack of higher rpm performance.
I've only driven the Argo up and down the road so far but it just seemed like a slug to some degree. And super noisy drivetrain too.

[liflod]

Valves should be set at .005 with the piston .25 past TDC.

[liflod]

http://www.6x6world.com/forums/engines/5923-briggs-18hp-vanguard-valve-adjustment.html

[spikedbat]

Valves should be set at .005 with the piston .25 past TDC.

Which is in metric 0.127mm.

Does anybody know the avg range of +/- that is safe for valve clearance or must it be bang on 0.005"?

[liflod]

.004 - .006

[spikedbat]

Just wanted to update you guys that I got it running fine..

took my buying an ultrasonic cleaner and running the carb in there with 50/50 mixture of Simple Green HD (non-corrosive).

Man it made a difference and came out clean. Idles down perfectly now and accerlerates as it should.

anybody ever within GTA area and needs to clean a really dirty carb give me a shout I'll run it through my cleaner for you.