broken needles

[Al Bouman]

I've had to replace 2 needles in the last two months of riding. What would cause them to break so often? I'm guessing the slide is worn out, but could there be any other causes?

 

[JasonWho]

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[CaptainObvious]

Where are they breaking? Is it the same spot? How does your throttle feel? Does it seem to hang-up?

 

[Al Bouman]

Both times they broke were while riding. The needles were broke off after the clip positions.

 

[Al Bouman]

Throttle seems to not have that nice crisp snap anymore either.

 

[CaptainObvious]

Hmmm, I think that there is something out of alignment inside the carb. If you can, try a different slide. Also, inspect the needle seat. Something is out of whack.

 

[Al Bouman]

Thanks RV6junkie. I'll tear the carb down and see if I can find something out. Then try another slide.

 

[XRDadKDXBeni]

Sounds like an alignment problem in the needle not going back into it's seat. It could be coming out of the seat and then causing the slide to hangup ultimately breaking the needle at it weakest point (the clip grooves). Do you have a correct amount of play in the throttle cable? Also check the needle seat to ensure it is seated in the carb body correctly. Is the needle retainer (scre on cap) in place? Needles in carbs do not break frequently unless there is a problem. We have never had this occur in 35 years of riding. Hope you find the problem.

 

[canyncarvr]

You can take the fuel bowl off, remove the main jet. Then, with throttle activation, watch how the needle aligns to the needle jet.

re: broke off after the clip position

I don't understand 'where' that means. AT a clip groove but below the clip? At no groove at all?

Are the needles scored or marked?

When the retainer nut is installed, does the needle wiggle (it should)?

Any chance of an install 'issue'? About the time the slide gets slid is about the time the needle tip hits the needle jet. There should never be any force applied to the needle or jockeying of the slide trying to make it fit. If it's lined up it will slide in easily.

Any feeling of obstruction, tension or stress during the slide install?

Do you install the slide with the carb tight in the boots? Don't. At least loosen it and rotate the carb for easier slide install. Or completely remove the carb to remove/install the cap.

Speaking of cap, it is threaded on the carb body correctly, correct?

 

[shr]

Are you using the stock E-clip, or has it been replaced with a hardware store replacement? And forcing it on.

 

[Al Bouman]

Thanks for all the input, you all are a great help!

As far as where the needle broke, it's right below the lowest clip position. I didn't check the needle for wear yet I will have to take a look. When I reassembled the needle and put it all back in the carb it did not go in real easy. I had to pull it out a couple of times before it slid in. So it does feel like it's out of alignment. I need to take it apart more and inspect the alignment.

The clip was on the bike when I bought it last year, so I'm not sure if it is stock or not.

My daughter just got married this week end so I haven't had time to work on the bike since I started the post, but will get back to it this week and let you know what I find.

 

[FLBob]

When all is right doesn't the needle always stay in the jet? Sounds like something is grossly wrong -like in correct needle, or ?

 

[canyncarvr]

The correct clip will slip on fairly easily. One from the hardware store will have to be forced. It's too thick!

re: when all is right...
It doesn't stay in the main jet.

My reference to the tip hitting the needle jet was concering installation of the slide.

Maybe take a look in the carb throat (carb out of the boots but still attached to the bike with the throttle cable), to 'see' how it all fits.

Seems indeed something is 'grossly wrong.'

 

[Al Bouman]

I had a friend who has been riding and working on 2 strokes for 25 years take a look at it. He pulled the carb apart and watched the alignment as we moved the throttle. It lines up dead center, but there is quite a bit of play in the needle from side to side if we move it around by hand. He seemed to think that if the needle vibrated just right it could possibly get caught some how, he has never seen that happen before.

After the 1st one broke I ordered needles from Sudco:
p/n ke 017.462
description 48-ccj pwm j/n
All of which means nothing to me other than that's what was recommended.

 

[CaptainObvious]

CCJ...There's one I haven't seen anyone use yet. Maybe we can get a 20 page discussion going on it ;)

 

[Al Bouman]

Another needle bites the dust. Another push out of the woods.

Anyone have a good connection for a carb? I'm done messing around with this one.

 

[canyncarvr]

You might talk to ron @ rb-designs here. Have him set you up with a modified 4-vent air stryker. ;)