87 Force 85hp Difficult starting

[smorse1]

Got into some shallow water and messed the prop up today. Fortunately it was an old one and had been rebuilt and I have a new one ready to go. It broke off about 2" of one blade.
After raising the motor to check it out, it started hard, and wouldn't idle very well, kept dying. I finally got it to run just enough to jam it into forward and rev the motor up, this got us back to the boat ramp, anyway. I it seemed like it was missing - I didn't realize that the prop had been broken until I got back to shore.
The question - did I damage the motor by running it in what I think was just some silty water? Did I damage it by running it with the broken prop for 20 minutes?
It seems like a carb or fuel problem but it'll just fire and then die at this point.

 

[Jiggz]

Re: 87 Force 85hp Difficult starting

You had a hard bottom hit breaking a prop. When this happens, there is also a possibility the flywheel key could have sheared and messed up your timing. Check your timing first and if it is off, time to open and inspect the flywheel key.

 

[MickLovin]

Re: 87 Force 85hp Difficult starting

Ah thanks Jiggz, I learned something today.

 

[smorse1]

Re: 87 Force 85hp Difficult starting

Ok...new observation. I had someone who knows the motor come take a look he didn't think it was the timing - we opened up the fuel pump, the diaphram looks good but could use replaced. what we observed as it was running rough, the carbs were dripping gas - all 3 of them. The thinking is that the motor is actually flooding. His proposal was to fix the fuel pump and rebuild the carbs. Does this sound like an appropriate diagnosis? He's quoting me $500 for this work including parts.

 

[Jiggz]

Re: 87 Force 85hp Difficult starting

So what happens if after the proposed repair the motor is still the same, i.e. running rough? Another $500 to check the timing?

The carbs flooding doesn't have any relation with the fuel pump. (Do not confuse flooding with overflowing; the first is the presence of too much (too rich) fuel in the air-fuel mixture entering the intake while the latter is the overfilling of the bowl and raw fuel exits the carb's vent hole caused by improperly set float or faulty needle and port inlet seats) The fuel pump is working perfectly as it delivers required fuel. The reason they are flooding is because of two things: Blow back from the reeds or the choke is not in full horizontal. Blowback from the reeds can be result of two things, improper timing or broken reed petals (I doubt this is the case unless by coincidence all three sets of reeds are broken or bent).

I still recommend checking the timing which is not really that hard to do. There is a sticky post on the top of this thread forum that has a video showing how to check the timing. If you do not have an inductive timing light you can get one for less than $20 from harbor freight. And if you can connect a red wire to a positive terminal and a black wire to ground or negative terminal, you can do a timing check or even set it if you want.

 

[pnwboat]

Re: 87 Force 85hp Difficult starting

+1 with what Jiggz says. $500 is way out of line, but that's just my opinion. That mechanic must be pretty proud of his work! Pretty easy to fix all of those issues if you are somewhat mechanically inclined.

 

[smorse1]

Re: 87 Force 85hp Difficult starting

I totally agree, I am somewhat mechanically inclined, but don't have a ton of time to work on it. But I am headed to Harbor Freight to get me a timing light. I'll see what I can do from there. I really appreciate the advice!