79 75hp will not get to WOT

[57 7.5]

Hi guys, been awhile but just got me a 85 Astroglass with a 79 75 hp on it. Guy said it ran fine last year have receipt from where he had it serviced, carbs rebuilt, new gas lines on motor and to tank. Took it home cleaned it all out, drained the fuel and replaced with 50:1 mix. Hooked a hose up, squeezed the bulb and sprayed some gas mix in the carbs and turned it over, started and then died repeated two more times fired up but runs rough and doesn't seem to be getting up to WOT. Took it to the lake fired it up it idled but still rough backed it off the trailer and took off slowly and it was going but never got up to WOT. Went a 100 yards and died, restarted and never would get past idle speed, turned around and went to the ramp and never got it to go past idle without dieing. I'm thinking the carbs needs cleaning? Any help would be appreciated. Also looking for a good used prop at a reasonable price. Will get back with the prop details when i get home this afternoon.

Thanks

 

[procraftguy]

Re: 79 75hp will not get to WOT

Sounds like bad carb adjustment maybe someone can jump in with better instructions but usually lightly seat then back off 1&1/8 then go from there

 

[57 7.5]

Re: 79 75hp will not get to WOT

Well I read several post and synced the carbs (video was awesome on this) and got the timing set. I had it running on the hose and it was WOT and running great and I let off the throttle and it backed fired and I shut it off. Thought it might need some tweaking and thought I would do it today at the lake. Got to the lake and it wouldn't start at all. Found out no compression in cylinder 1 & 2, got home read some more post on compression and whala blown head gasket as a lot of people said check first. Will find the gasket and get it back together and try it out. Everything looked ok with piston and cylinder walls. Cross your fingers!

 

[57 7.5]

Re: 79 75hp will not get to WOT

head gasket was blown. Replaced it today and she runs great out on the lake, dies at idle though, so I'm off to read threads on that.

 

[jerryjerry05]

Re: 79 75hp will not get to WOT

The carbs,set at 1 turn out for inital adjustment.
The idle is set at the towershaft. It's set at about 1150-1200 in the drive.
The rpm's in gear,in the water should be at 775-800.
Once the carbs are cleaned and everything is right.Fuel pump diaphram replaced.
The gas lines all replaced.A filter installed just before the pump or just before the carb(wally world-G2/G12)
Once it's running, then in the water,motor warm.
Turn the top carb air sccrew in 1/8th of a turn.Wait 10 seconds.This burns the fuel at the old setting.
Then another 1/8th turn wait 10 seconds.
Do this until the motor bucks,kicks or stalls.
Then out 1/2 turn.
Repeat this on the other carbs.
Then reset the RPMS and do it again.

Just worked on a 1985/85hp It still had the foam cowling in the hood.
Remove it if it's still in there.
It can fall apart and clog a carb and burn a cylinder.