CR500/KX500 Fuel Primer

[Mofood]

Just finished installing the primer with the smart carb. It started hard before when it was cold, but after a few pumps of the primer, it fired up fist kick. Way worth the $25 and a few hours of work.

Would you show a pic of how you mounted the primer plunger? Haven't thought about under the intake. Looks clean. I'm doing my primer right now.. hopefully get my kx on snow!

 

[wwillf01]

Would you show a pic of how you mounted the primer plunger? Haven't thought about under the intake. Looks clean. I'm doing my primer right now.. hopefully get my kx on snow!

This is on my cr but maybe it helps...

 

[adamd1979]

I had a hose that was a tight fit under the intake, and then when I shoved the primer into it, it was even tighter. I'd have to yank on it pretty hard to get it back out. Should work.

 

[portgrinder]

anybody got a rock solid system for firing these things up when they sit outside overnight?

i always get mine going. just trying to nail down a system.

ie 3 shots of primer, leave choke on and no throttle. or whatever the case may be.

you almost can't go by the plug it seems. mine can be visibly wet and still need more fuel to flash up.

 

[M5-]

I haven't tried to fire my Cr500 up after being out all night so I'd also like to know what works. I have a primer I just haven't installed it yet, kind of hoping I won't need it, I've been doing the bike tip over routine so far so good.

M5

 

[wwillf01]

anybody got a rock solid system for firing these things up when they sit outside overnight?

i always get mine going. just trying to nail down a system.

ie 3 shots of primer, leave choke on and no throttle. or whatever the case may be.

you almost can't go by the plug it seems. mine can be visibly wet and still need more fuel to flash up.

I have the primer... I press it three times and pull the choke on the smarty fires second kick as long as it's top dead center start

 

[M5-]

So I added the fuel primer on my CR500. The first day I ran the bike I had no primer and the bike flat out ripped all day. Second day with the primer the bike ran like a POS. I'm having a few consistency issues and I'm just looking at all the options. I think my issues are a combination of things but my question related to the primer is:

Have any of you guys noticed that the primer may be leaking fuel into the carb due to vibrations from the bike making it pig rich?

M5

 

[wwillf01]

So I added the fuel primer on my CR500. The first day I ran the bike I had no primer and the bike flat out ripped all day. Second day with the primer the bike ran like a POS. I'm having a few consistency issues and I'm just looking at all the options. I think my issues are a combination of things but my question related to the primer is:

Have any of you guys noticed that the primer may be leaking fuel into the carb due to vibrations from the bike making it pig rich?

M5

Not for me.... I actually use 5 pumps to start and if it sits a couple during the ride... I think my bike is a little on the thirsty side.


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[ravenous]

We noticed the same problem on my friends KX500.
He added a tiny shut off valve to his primer system and the problem disappeared.

 

[M5-]

We noticed the same problem on my friends KX500.
He added a tiny shut off valve to his primer system and the problem disappeared.

Thanks. That's what I was thinking I may need to do. Where did you source the valve? 1/8th inch?

M5

 

[wwillf01]

We noticed the same problem on my friends KX500.
He added a tiny shut off valve to his primer system and the problem disappeared.

The only way you would notice is if you bike is running rich right? Is there a way to see it...? Anyone else of this issue?


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[mtn-doo]

The first KX500 I installed on, this thread starter, is waiting for an LT kit. No info on it. The primer should not allow extra fuel to leak through? We are using it as it was designed for.??? Hummm... The 1/8 inch shutoff is an excellent idea. The vibration on the primer plunger is obviously causing some extra fuel to get past. Great find! If someone can post where they are finding the 1/8 shutoff. That would be great.

 

[portgrinder]

my kx500 needs 5 shots when left outside.

maybe the o-rings in your primer are shot. thats the only way i can see it leaking enough to matter. and if you had head pressure on the primer ie the primer located below the fuel tank and fuel bypasses thru.

 

[M5-]

My primer is brand new, what I think is happening is the valve vibrates because it is mounted to the frame of the CR500, this makes the primer act like a little pump. When you think about the size of the hole in your main jet it doesn't take much leaking to screw up your jetting.

M5

 

[Mofood]

My primer does not leak into the crankcase (kx5 smarty). Works as expected. Could be an air leak? I used an oring to seal and 6mm tap into a smatcarb intake side.

 

[wwillf01]

My primer does not leak into the crankcase (kx5 smarty). Works as expected. Could be an air leak? I used an oring to seal and 6mm tap into a smatcarb intake side.

I wonder of our Smarties are just accounting for the extra fuel that's why I wonder if there is some other way to notice... I will have to look at my lines next time I am out to see if fuel is moving...

 

[M5-]

I took the primer off and problem gone, that said I also made a few other changes. If I re-install it I'm going to just add a valve, no big deal or cost.

M5

 

[mtn-doo]

Here are two different 1/8" fuel shut off's. I ordered two of each to try. The "Sky Cruiser" small black ones look very nice and simple. They also have 1/8" double locking clamps for that tiny hose.


http://www.radicalrc.com/search/RRCFSOV

http://skycruisermfg.com/accessories