dry cylinders

[rsw21282]

i have a late 80's 85hp force, it was running ok but had some problems at higher rpm, i took a look at the fuel pump and the diaphragm was punctured so replaced and put back together. Had it running yesterday was fine got to the boat ramp and the thing wont start, took plugs out and there all dry(bone dry) i am getting fuel to the carb bowls so is it that the carbs r messed up? my bigger fear is it would be something like a cam or valve prob. another question, if all cyl are dry three seperate carbs what one problem could effect all the cylinders?

 

[Bob_VT]

Re: dry cylinders

Is it a 2 stroke? If it is you do not have valves or a cam.

First establish if you are in fact getting fuel. Is the fuel pump actually pushing fuel through the system?

Do you have a vacuum leak that is allowing air to be sucked in and not fuel?

How is you spark too?

I think if it is all 3 carbs I would look at the fuel pump first. Have someone squeeze the primer bulb as it is being cranked. There is even a possibility that your fuel line is plugged too.

 

[rsw21282]

Re: dry cylinders

it is a two stroke, i just got done cleaning the carbs and they were all full of fuel they where not very dirty either im not sure cams or what i was looking in my manual and it was talking about reed valves not sure if that could be it. when i took the carbs off the inside of the eng. where the carbs mount was dry to so i am thinking it is a carb problem, but all three doesnt seem likely, does the fuel pump have to push the fuel through the carb to or is it sucked out? all i did was change the fuel pump diaphragm is there something else i should check?

 

[Frank Acampora]

Re: dry cylinders

On a cold start, are you choking the engine? are you setting the control handle to fast idle position? How many turns out are your low speed idle needles?

If gas is in the carb bowls, they MUST be delivering fuel unless the low speed circuit is clogged or the low speed needles are set too lean. It is very rare for the high speed dip tube to be clogged and not deliver fuel when enough air is passing by it.

With the throttle closed, not enough air passes the venturi and no fuel will be drawn up the large brass dip tube. Then, if the low speed needles are set too lean, no fuel will be drawn up the thin low speed brass dip tube.

AND if the engine is cold and you do not choke it, not enough fuel will vaporize to start the engine.

Since you cleaned the carbs, the suspect condition is there. Did you set the float height properly?

Your style of writing tells me that you have very little idea of how a 2 cycle engine works. Thus you will be confused. You also seem to have a manual but seem to have trouble understanding it. So, don't be afraid to ask questions.

I suspect that no one has told you proper starting procedure for these engines. If not, ask and we will explain, because with some engines, if you don't follow procedure, they are balky and some just refuse to start.

Answer the couple of questions I asked and we will take it from there.

 

[rsw21282]

Re: dry cylinders

im not very savy as far as 2 strokes, grasp the basic concept and as far as marine eng. never messed with them. I am an aircraft mech. so on a pride thing it dont want to take it to a shop and im good with mechanics if i get a bit of help on new things. Anyway cleaned carbs got it started, idles faster now althought that could be because i primed the crap out of it and choked it, i had to take the white wire off to start it again and as soon as i reconnect it, it dies. I checked the ignition switch for continuity between the m terminals when the ignition is set to start and it is good, also the switch has power to the red wire so im thinking its not the ignition switch(but wouldnt be the first time i was wrong) and another thing about the ignition switch sometimes when trying to start it will engage the starter and others it is just dead, i checked the solenoid using a momentary switch and pos. wire off common bus and it works that way. About the carbs the bottom one had a small ball bearing in the draw tube but in my manual its not in there and the other two had a spring(just above drain plug) is that norm? this whole dang eng. seems a bit sketchy to me and tempermental, it worked yesterday and today nothing.

 

[rsw21282]

Re: dry cylinders

another question while i have your ear frank, what is an L drive i asked a guy at a marine repair shop the other day and if u can believe it he didnt know.

 

[noah4009]

Re: dry cylinders

I checked the ignition switch for continuity between the m terminals when the ignition is set to start and it is good, also the switch has power to the red wire so im thinking its not the ignition switch(but wouldnt be the first time i was wrong) and another thing about the ignition switch sometimes when trying to start it will engage the starter and others it is just dead, i checked the solenoid using a momentary switch and pos. wire off common bus and it works that way.

I may be fishing here, but I had a similar problem with my ignition being good as well as battery and when I tried to start sometimes it would turn over and other times it would not. I knew next to nothing about motors, (still do LOL) I found out later the shift arm was not connecting or pushing in the tab on the neutral interlock switch. the purpose of this switch is to prevent you from starting it in gear. And if not set properly, even tho in neutral it wont let the engine turn over to start. Good luck

 

[rsw21282]

Re: dry cylinders

just checked my nuetral interlock and its good, think i might have found my start or dead problem(faulty breaker down the line) im still stuck with the white wire disconnected problem, there is one wire going to the bus and two that could hook up to it on the other side, only one was hooked to it(my manual shows two hooked up) but as soon as i put that one on it dies, and iv tried interchanging and everything the only successful way of starting is if one of those wires is disconnected(almost like that second wire has no effect on anything) so conclusion as long as white wire not connected will start, does that mean bad cd box?

 

[rsw21282]

Re: dry cylinders

well i just got it to run for a min. with the white wire hooked up, so my theory of a possible ground in the white wire is kinda shot unless it was just not touching at bare metal at that time. K guys im bout outta ideas im going with the cheapest solution changing plugs even though they dont look bad or old.