Problems during compression test on 1966 9.5 hp

[spg59]

Hi All,
Well, I really hope I didn't just hurt my motor. I went to perform a compression test and forgot that I still had my fuel line connected and pressurized. When I pulled the manual start I noticed that fuel was leaking at the lower unit out the small weep hole on the underside of the fin. What just happened?

 

[highcountry]

Re: Problems during compression test on 1966 9.5 hp

No way that you hurt anything, I would guess that you just flooded that cylinder real good.

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

Hi All,
I tried starting the motor and still nothing. This motor has a new carburetor kit, new ignition parts (coils, plugs, condensors) and the the head and pistons have been decarboned. The primer bulb gets hard and there are no leaks at the carburetor. I did notice when I pulled the motor out of the test tank that there is still fuel leaking out the small drain hole below the fin of the lower unit. Any ideas?

 

[Daviet]

Re: Problems during compression test on 1966 9.5 hp

All it takes is spark, compression and fuel to run. What kind of compression do you have?
Did you check spark with an air gap tester after you replaced the ign componets, do you have a bright blue spark?
Try squirting fuel mixture into the carb and see if it will start, maybe a carb problem.
You did inspect the flywheel key and torque the flywheel to proper specs didn't you.

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

Hi Daviet,
I'll try with spark gap tester this week. Flywheel key and torque were good. Carb. was well cleaned before new carb kit was installed. What should compression be on a cold motor? Thanks for all help.

 

[Daviet]

Re: Problems during compression test on 1966 9.5 hp

I would think your engine would start and run on 80-90#'s compression.
When you overhauled the carb, where did you set the low speed jet, 11/2 turns out?

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

The service manual for this motor said 3/4 and I haven't changed that. Should I open it up to 1 1/2 turns?

 

[Daviet]

Re: Problems during compression test on 1966 9.5 hp

I would check spark and compression first and make sure they are correct. Then we only have to troubleshoot the fuel system.

 

[Monte1961]

Re: Problems during compression test on 1966 9.5 hp

I agree with Daviet!

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

Should I remove both plugs before I start the compression test even though I'm only checking one cylinder at a time? Also, should I spray a little fuel/oil mix in the cylinder to help with lubrication?

 

[AlTn]

Re: Problems during compression test on 1966 9.5 hp

both plugs out...no fuel mix needed

 

[1946Zephyr]

Re: Problems during compression test on 1966 9.5 hp

Low speed sets at 1 1/2 turns out. High speed has no adjustment. If you're seeing a lot of fuel, then I would check the fuel pump and make sure the diaphram isn't punctured. If you remove the fuel pump, squeeze the primer bulb and see if fuel leaks out, where it mounts to the engine. If that doesn't solve it, then your float level may be off.

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

I just completed the compression test. Results are 60 psi on #1 and about 65 psi on #2. This was done with the motor cold. The motor has sat a long time do you think I should remove the head and spray a little WD-40 or BB-Blaster on the cylinders incase maybe the rings are sticking and leave the with the cylinders facing up overnight. When I replaced the head gasket previously I already decarboned the tops of the pistons and the head.

 

[wifisher]

Re: Problems during compression test on 1966 9.5 hp

Put a little oil in the cyls, and do the compression test again. Leave the head on.

When you try to start it, if there is gas dripping out of the LU, the engine is most likely flooded. Choke off and throttle open when trying to start.
(Just in case you didn't know that)

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

I did have a little fuel/oil mix coming out the LU after compression test. To have the throttle open, then you want me to try it in forward gear? I did the compression test in neutral previously because I read it didn't need the throttle open on 2-strokes. Let me know about in forward gear and I'll spray some oil (Do you mean fuel oil mix or WD-40?) in the cylinders.

 

[wifisher]

Re: Problems during compression test on 1966 9.5 hp

Leave it in neutral. The reason for opening the throttle is to allow more air to mix with the flooded motor. "Flooded" means too much gas in the cyls. Without air, it can not ignite properly. If/when the motor starts, close the throttle to prevent it from over-revving. For the oil in the cyls, just use some two cycle oil. It will make the motor smoke a lot if it starts, but may raise the compression enough to get it to fire. (this is obviously a temp. fix)

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

Well she didn't start, but it did cough a couple times which was promising. However after three attempts the manual starter is locked and I can't even pull it. Suggestions?

 

[Monte1961]

Re: Problems during compression test on 1966 9.5 hp

is the throttle past the start position? if not, what do you mean by locked?

 

[spg59]

Re: Problems during compression test on 1966 9.5 hp

No, I tried starting the motor in neutral. The throttle won't advance in neutral. Did you want me to attempt the start in gear? I'll get back with you guys again tomorrow. My wife is starting to think I married this motor. I'm sure some of you understand. Thanks again.

 

[JustinC]

Re: Problems during compression test on 1966 9.5 hp

Was the motor running before you attempted the compression test? Also if you pressurize the bulb and dont try starting it, are you getting any fuel leaks anywhere? (out of the throat of the carb, or LU) When you pull the plugs, are they soaking wet?
Sounds to me its going to be fuel related. Float stuck open possibly flooding the motor.

Good luck!