v135 possible ignition problem?

[brielly]

The engine is a 91 v135. The engine doesn't like to restart after running for a while, smokey at startup and has a rough idle. Today I ran it in my driveway and pulled the plug wires. Here's what I found. All had spark. Cylinders 4, 5, and 6 caused the engine to noticeably bog down when I pulled the wires. 1,2,and 3 did not cause the same change in engine speed. They did however have spark and when I put the wire close enough to the plug the spark jumped and caused a slight pick up in rpm's. Can anyone tell me what this means???

 

[CharlieB]

Re: v135 possible ignition problem?

First you need to test spark intensity , pass/fail to determine if yours is a weak ignition or a fuel related problem.

Intensifying the spark by creating additional gap is a sign of a potentially weak ignition on that side. You could have an ignition module that is just beginning to fail. Testing is required. No return on electrical parts.

Search this site for Joe Reeves spark gap tester. Joe posted directions for building your own tester, it is a REQUIRED tool, very effective in determining what direction to proceed with diagnosing engine problems.

If it is a weak spark on one side then follow the steps outlined in the Ignition Troubleshooting Guide posted here on iboats and also at CDI/Rapair

 

[Ed R]

Re: v135 possible ignition problem?

1,2,3? you know , port side of motor is 2 4 6 and starboard side is 1,3,5. Now, what cylinders are not fireing ?

 

[brielly]

Re: v135 possible ignition problem?

Thanks I did check to make sure I had the cylinder numbers right. All cylinders have spark but when I pulled the plug wires on 1, 2, and 3 there was no noticeable drop in rpm's like when i pulled the wires from 4, 5, and 6.

 

[Ed R]

Re: v135 possible ignition problem?

OK, 4, 5,6, ? at idle , ?? or WOT ?

 

[brielly]

Re: v135 possible ignition problem?

This is at idle. The boats runs real well at wot but when after running for a while when I back off the throttle it sputters and sometimes dies. Restaring it at that point becomes difficult and then if i do get it running it dies when i give it gas.

 

[Ed R]

Re: v135 possible ignition problem?

You know , 5,6, is bottom carb, and its alway the carb, [ the bottom] to get clogged with dirt; etc, after winter, right ?

 

[brielly]

Re: v135 possible ignition problem?

I rebuilt the carbs only a few weeks ago and yup the bottom one was a mess. I was advised that I didn't need to remove the mixture screws to do the rebuild but now I'm wondering if that was bad advice. I'm not certain but doesn't that part of the carb control idle and lower rpm operation?

 

[j_martin]

Re: v135 possible ignition problem?

I rebuilt the carbs only a few weeks ago and yup the bottom one was a mess. I was advised that I didn't need to remove the mixture screws to do the rebuild but now I'm wondering if that was bad advice. I'm not certain but doesn't that part of the carb control idle and lower rpm operation?

Yup, you got that one right. It was bad advice.

hope it helps
John

 

[Ed R]

Re: v135 possible ignition problem?

Yes, they only! , control idle speed.

 

[Ed R]

Re: v135 possible ignition problem?

Pull of bottom carb again, and blow out pickup tubes, with carb cleaner and reset , reckeck, float height. Set idle srews at 1 an a half turns.