[ss313]

I am having an issue with jetting my '07 CRF230F that I can't figure out.The bike was running fine but had the common cold start issues. I took the baffle and and air box restrictor out and installed a 45 idle jet, 120 main jet, and 03-05 needle with the clip in the 4th slot. The bike starts and idles better than it ever has but at about 1/2 throttle to WOT it starts cutting out. I pulled the carb and checked to make sure I hadn't messed up the parts install and everything looked ok. It ran the same so I took it apart again and cleaned it thoroughly. It ran the same again. I put a new plug in it to rule that out. No difference. I put the baffle back in and it bogged really bad and still cut out. As a last resort I put the 102 jet back in and the restrictor in the airbox. The cold start issues are gone and the bike runs like it did before.

Has anyone had this kind of issue before? Usually with jetting issues I've seen bogging or power issues but not cutting out like this? The bike is ok like it is but I would like to take advantage of the extra power that is available from uncorking it.

[kunkle]

What you put in is Coe jetting specs which were originally pinned down by a lot of dyno work on a 230F by Mike Coe. It should run great that way.

You put the clip in the 4th slot down from the top and not the bottom, right?

Seeing how it's acting up in the upper 1/2 of the throttle- probably something to do with the main jet. Did you put the 102 jet back with the stock needle or with the 03-05 needle?

Since it's already out, hold the 120 jet to the light and look thru the bore and make sure it's perfectly round and clear.

120 jet can't be too lean- unless it's obstructed. Makes no sense that a 120 would be too rich since the Honda power-up kit uses a 132 jet and they run OK with that.

[ss313]

The clip is in the fourth slot down from the top, yes.

I left the 45 pilot jet and the 03-05 needle (on the 4th slot) in it and just changed the main jet.

It doesn't make any sense to me either. If it hadn't started running right with the 102 I would say that it had an ignition problem. It doesn't cut out consistently but it is repeatable. It always acts up at mid throttle but sometimes when you open it up it just takes off with no issue then you can let off and open it up again and it will break your neck from jerking back and forth.

[kunkle]

So basically, you have Coe jetting but it acts up mid throttle which goes away if you do nothing but change the main back to stock 102? Will it run to redline at all?

Bizarre to say the least. You could try a plug check- new plug in engine, go wide open throttle to redline, kill the engine, stop and pull the plug, check to see if it's really rich or lean.

Other than that I suppose it's possible to have a defective jet (opening size-wise). I'd try a different jet one size up or down if you have any and see how it acts.

[ss313]

With the 102 in it you can rev it as far as you want to. With the 120 you can rev it sometimes but it is hit or miss.

I will try to do a plug check but it may be next weekend before I can.

I had also thought of trying to get a couple of smaller jets. I'll see what I can find in town and try them.

[Enmerdeur]

The 120 is probably too rich for your bike. Should try a 118 or 115 main

[Aussiecrf230]

What is your height above sea level?
As we ride at higher elevations we need smaller jetting do keep the mixture correct.

[ss313]

I an only 100 feet or so above sea level and the riding that I have done has been at home.

I haven't had a chance to do anything else this week but hope to this weekend.

[Aussiecrf230]

If the 120 main looks like it is clear reinstall it and move the clip to the 3rd (middle).
Make sure you float is set right and baffle (around the main) didn't fall off.

I would be surprised if you had to go to a smaller main.
Ensure there is sufficient fuel be delivered to the carb (nothing blocked).

From what you have described it sounds like it runs out of fuel, gets some more and runs out again.

Check breather hoses are not blocked or collapsed too.
Weird things happen when they are.
Wouldn't be the first time they end up routed wrong after a jet change and problems arise because they are crimped.

Good luck and let us all know how you go.

[ss313]

Well I don't know what I did but it is running correctly with the 120 main now.

I took it back apart and recleaned everything. I drilled out the holes in the plug on the bottom one drill size larger but I don't think that this had any affect.

The thing that I did find when I moved the clip up to the third slot was that the needle had rubbed something enough for me to see it and feel a ridge with my fingernail. I polished the ridge out,put it back in, and made sure that nothing was binding or rubbing as best I could and the bike runs like a totally different bike now.

Thanks everyone for your suggestions.

Scott

[kunkle]

Glad to hear it's running right- that's frustrating running into crap like that and you still don't know what was wrong!

How do you like the Coe jetting? Notice much difference?

[Aussiecrf230]

Where abouts on the needle did it leave the mark?
Glad to here it runs OK now.

[ss313]

about 2/3rds of the way down from the top.

[Aussiecrf230]

That sounds like it wasn't quite vertical when you lowered the slide. As long as it is free now you should be sweet. You sometimes get damage like that near the idle end of the needle if the jet needle is not centred properly.