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Quick carb question

S

SaltyScot

Regular Contributor
I have a 1975 Evinrude 135hp and have had some running issues. After going all through the spark side of it, I turned my attention to the fuel side. I found that whoever was inside the carbs last didn't put in the little clip that connects the needle to the float in each carb. What would be the effect of that on running? Is it just relying on gravity for the needle to drop until it decides to get stuck? Upon reassembly with the clips in place, it's running much better although I haven't been able to water test it yet. Thanks.

Stephen
 
My understanding, Early carbs, on smaller motors didn’t use the clip, gravity dropped the needle. BUT, they used all SS needles.
Newer versions use a small synthetic tip, where the needle seats. Apparently that resulted at times of the needle sticking in the orifice. The cure was a clip, so the weight of the float pulled the needle free.
Any sleuthing to determine engine issues starts with a compression test, using a gauge known to be accurate.
Next- does each plug fire a hot blue spark across the 3/8” gap?
What are the actual symptoms, & when do they occur? What work has been done? It’s not enough intel to state “running issues”.
After all, you wouldn’t tell your doctor, “I don’t feel quite right”, & expect him to help you without a lot more questions & answers.
 
Edchris177 said:
My understanding, Early carbs, on smaller motors didn’t use the clip, gravity dropped the needle. BUT, they used all SS needles.
Newer versions use a small synthetic tip, where the needle seats. Apparently that resulted at times of the needle sticking in the orifice. The cure was a clip, so the weight of the float pulled the needle free.
Any sleuthing to determine engine issues starts with a compression test, using a gauge known to be accurate.
Next- does each plug fire a hot blue spark across the 3/8” gap?
What are the actual symptoms, & when do they occur? What work has been done? It’s not enough intel to state “running issues”.
After all, you wouldn’t tell your doctor, “I don’t feel quite right”, & expect him to help you without a lot more questions & answers.
Click to expand...
Thanks for carb info. That answers my question.
I took it to the dock today, but it's still having issues. I'm actually not ready to start troubleshooting my issue, which is that is not able to accelerate past idle. I can put it forward or reverse and it doesn't die. But it won't go beyond 1000rpm. It was running fine, and then this problem began. But I'll start a new thread in a month or so when I'm ready to get back into it. Thanks.

Stephen
 
SaltyScot said:
I can put it forward or reverse and it doesn't die. But it won't go beyond 1000rpm. It was running fine, and then this problem began. But I'll start a new thread in a month or so when I'm ready to get back into it. Thanks.

Stephen
Click to expand...
Make sure the Throttle Cam Bushing Part# 0314137 is there. It's #91 on the Cylinder and Crankcase parts diagram. If that bushing is missing the throttle cam will not engage the linkage to advance the timer base at the right moment and can cause bogging issues when accelerating.
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Thanks, I actually remember that part from a 8hp Johnson where it was missing.

But I did finally find the issue with my 135hp Rude. It was just a sticking timer base. Back to rippin'(y)
 
SaltyScot said:
Thanks, I actually remember that part from a 8hp Johnson where it was missing.

But I did finally find the issue with my 135hp Rude. It was just a sticking timer base. Back to rippin'(y)
Click to expand...
I wondered if it might be a sticking timer base. A worn or missing nylon roller is also a very common cause of the symptoms you had. Glad you got it fixed.
 
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