BF8A & Sore Wrist (Hard Starting)

[simpleinterest]

I just bought the motor used and was told that it had starting trouble. I removed and cleaned out carb and jets and it started on the second pull. That was two weeks ago and now I have difficulty starting it. When it does start, I'm never sure what I did to get it to start.

- I once spritzed fuel into the intake and it started.
- Another time I spritzed fuel and it didn't start.
- Another time, opening the throttle as wide as possible in neutral (which is not very much) got it to start.
- Another time, opening the throttle made no difference.
- I've experimented with all three choke settings.
- I've pulled and pulled. My wrist is getting sore.
- Tomorrow I will try standing on one leg.

I've done a lot of reading on this particular engine and some information seems to conflict. Some say these motors are just cold blooded. Others say they should always start by the second try. Of course, I guess it depends on where you live in the US. I live near Seattle.

I've also read that you should open the close the throttle a few times prior to starting. I'm not sure what this does since I don't think this carb has an accelerator pump.

Anxious to get this resolved because we're supposed to be racing our sailboat on Saturday.

 

[simpleinterest]

Forgot to mention that compression looked ok, though a little uneven.

 

[km1125]

"open the close the throttle a few times prior to starting" won't do anything, other than exercise your wrist.

If the carb is clean, then it shouldn't be an issue to start. What's the spark plug look like? (clean? fouled?) Do you get a nice spark?

When cold, you should fully apply the choke, but only for maybe one pull. If it doesn't start, then I'd be opening up the choke at least part way. If it fires at all, but maybe not start I might leave the choke on for the next pull.

 

[simpleinterest]

Spark plugs look brand new. I think the PO replaced them. I don't know what a 'good spark' looks like, only that it does spark.

 

[flashback]

Did you clean out the fuel tank? Sounds like you had it running after cleaning the carb and now it's stopped up again.. good luck with the race!

 

[MattFL]

Check that the proper spark plugs are being used and check the gaps. Next time it won't start, crack the drain screw on the carburetor and see if any fuel comes out. If not, then that's your problem.

 

[simpleinterest]

Thanks. There was definitely fuel coming out of the bowl and I also checked the gaps. I was able to get it to start this evening two times so far (with cooling off period between both starts). I suspect one problem might have to do with the linkage adjustment. When I turned the idle screw all the way in, it started right up.

 

[MattFL]

If the starting problem is when it's hot, then try just cracking the throttle to start it. Maybe 1/4 throttle. Hot 4-strokes like to be lean to start, cracking the throttle a little bit will help.

 

[simpleinterest]

Problem solved. It just needed a small linkage adjustment so that the throttle was open a little more when starting. After I replaced the carb, I adjusted the linkage a little bit because it was revving too high at idle. I think that is what caused the problem.

When I read about hard starting problems, nobody mentions linkage. Maybe this is another hidden cause.