After tune up-won't start

[LostOmen]

Ok, I replaced the coils, points, condensers and rebuilt the carb on my 1966 Fastwin 18. I'm getting a good spark on both wires with the spark tester. Fuel is getting to the carb. Compression is 100/105.

If I crank it 5 or 6 times, it backfires really loudly (manual start). I did notice some fuel coming out under the choke plate.

Any help is greatly appreciated!

 

[CATransplant]

Re: After tune up-won't start

Could you have switched the spark plug wires? That's one cause of backfiring and not starting.

Also, if you didn't torque the flywheel nut properly, you could have sheared the key that locates the flywheel on the crankshaft.

Those are the two most likely reasons for your problem, in order from the easiest to fix to the hardest. Check the first one.

 

[BKS72]

Re: After tune up-won't start

I hope I don't make you mad by suggesting this, but I only bring it up because I did it on a chainsaw one time - no chance you put the carb float on upside down or possibly the needle came unseated during reassembly? I just ask because of the fuel coming out of the throat of the carb.

 

[tashasdaddy]

Re: After tune up-won't start

both very true. also: http://forums.iboats.com/showthread.php?t=167352

 

[CATransplant]

Re: After tune up-won't start

The backfiring is the clue here, although I suspect that he's hearing a misfire through the exhaust, rather than a backfire through the carburetor. A common misinterpretation.

That exhaust misfire is typical of the reversed plug wires or a slipped flywheel. Sounds like a gunshot.

Now, if it's blowing out of the carb, the sheared key is more likely.

 

[LostOmen]

Re: After tune up-won't start

Well, the plug wires are right. I labeled the top wire before I started. It is definitely misfiring through the exhaust. (Like a gunshot)

BKS72- it is ENTIRELY possible and maybe even probable that I put the float on upside down. This is my first attempt at any work on an outboard, so put nothing past me!

tashasdaddy, I have it backed out 1-1/4 turns as the manual says....I'll try backing it out a little more. Thanks for the link!

I'll check the flywheel and report back...thanks for the help!

 

[LostOmen]

Re: After tune up-won't start

The shear pin looks good if that is in fact what I'm looking at. It is the tab that comes directly off the crankshaft that guides the flywheel on, right?

 

[Harker]

Re: After tune up-won't start

Not sure what kind of coils you have but the wires from the charge pack to the coil has to be right or it's just like reversing plug wires. Just did this on my 92...

 

[CATransplant]

Re: After tune up-won't start

Not sure what kind of coils you have but the wires from the charge pack to the coil has to be right or it's just like reversing plug wires. Just did this on my 92...

The outboard being discussed has the old universal magneto ignition. Different animal altogether.

 

[LostOmen]

Re: After tune up-won't start

I pulled the carb. When held upside down, I couldn't blow in the fuel hose fitting. When held right side up, I could blow in it. However when I turned it upside down, a bunch of fuel poured out of a hole on the throttle body side of the carb. Does that tell anything? From what I've read, it means the float is set correctly, right?

Is there any way something could be reversed under the flywheel causing the plugs to fire wrong? I am sure I hooked everything up the same as it was. I reversed the plug wires to check, but it didn't fire up. It didn't backfire though after about 10 cranks.

Thanks for all your help so far!

 

[tashasdaddy]

Re: After tune up-won't start

did you put the woodruff key back between the flywheel and crankshaft? did you torque the flywheel?

 

[LostOmen]

Re: After tune up-won't start

The woodruff key never came off. Is it the same thing as the shear pin? I am having trouble finding "shear pin" in the manual...

Flywheel is torqued at 40#, but I'm not sure its sitting down enough on the shaft.

 

[LostOmen]

Re: After tune up-won't start

Ok, an update... I reinstalled the flywheel and the carb. I'm not getting the backfire anymore after 25 pulls. This time I pulled the plugs after trying to start it and there is no gas smell on the plugs or in the cylinders. Gonna search for some reading on the topic.

Edit: Just went out and sprayed gas/oil mix in the carb to no avail. The "Outboard won't start" thread says to check for flooding due to the needle. Gonna look into that too.

I told myself I wouldn't get frustrated about this project.....hmmmm

 

[LostOmen]

Re: After tune up-won't start

Did a few more things this morning. Checked the float level and it seems to be ok as far as I know. Sprayed mix in the spark plug holes and still no go.

Has to be a timing issue then, right? I tried reversing the plug wires and everything. I'm about to set the motor on fire....

Oh and the reason I didn't get any gas in the cylinder last night (see previous post) is because I didn't hook up the blasted gas line. Now we're back to backfiring as well.

 

[Harker]

Re: After tune up-won't start

You didn't set your points to the wrong cylinder did you?

 

[Xcusme]

Re: After tune up-won't start

Check this thread....
http://forums.iboats.com/showthread.php?t=277221

Does your magneto wiring look the same?? It should....

 

[LostOmen]

Re: After tune up-won't start

That very well could be possible. I didn't know you could do that though. The manual says nothing about that...

 

[LostOmen]

Re: After tune up-won't start

Check this thread....
http://forums.iboats.com/showthread.php?t=277221

Does your magneto wiring look the same?? It should....

LOL that's my magneto...

 

[Xcusme]

Re: After tune up-won't start

LOL that's my magneto...

That was my point.....if you have kept your questons in ONE post...showing your magneto wiring and then asking why you had a firing issue, it would have been easier to follow along....not to mention having folks asking about possible sheared flywheel keys etc. Anyone can see the key is OK. Your other option would have been to provide a link, in your post, pointing to the magneto pics you posted...see my point? It just saves time and helps to get you the help you need-want.

 

[LostOmen]

Re: After tune up-won't start

You're not very tactful, but I get your point. But, it was a very specific couple of questions I was looking for answers to, not a general why isn't my motor running thread like this one. Also, if someone is has the same question, it is a lot easier for them to find this way.

Now, I am not trying to be the confrontational new guy. I hate when people do that on boards I have been active in for a long time. I hope we can leave it at this since we both got our point across.