Proper starting procedure 1971 mercury 800?

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Mar 28, 2016
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Many posts on starting, but none seem to pertain to the older 4cyl models. Im trying to start a 1971 mercury 800 80hp 4 cyl thunderbolt ignition. My control box does not have the ability to push in the key to activate an enrichener. I dont think my engine even has an enrichener. The guy I bought it from said to raise the high idle lever about half way, push the choke,, of course squease the bulb untill its hard, then just crank and start. Last year that worked ok, but it was very hard to start cold every time. This year, I just cannot get it to fire. I rebuilt the carbs, mixed up fresh gas, tried the old procedure, and it just isnt getting any gas in the cylender. Carbs are getting gas, but it isnt sucking gas through the carbs??? How does it even work? I thought all 2 strokes needed a shot of fuel to start,, and I cant find where this one has any provision for it,, to activate anyway.

So, what I need is a factory recommended starting procedure. Im sure its a runner as there were no problems last year except for dirty carbs, but once started, it ran out very well, even making max recommended rpm on stock prop at full throttle.

Oh by the way, I downloaded a service manual,, and it dosent have anything on the topic of starting!
 

GA_Boater

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What works for me;

Pump the bulb until it's hard, raise warm up lever maybe a little more, turn the key and push the choke button until it starts to pop. Many Mercs like a lot of gas when cold and bulb needs to be hard
 

racerone

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Turn key to " on " ---------Push the choke button , do you hear a click ?----------------Choke button must be pushed in while cranking.
 

alldodge

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2 cycles love spark plugs, when was the last time they were changed?
 
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Soo,,its just supposed to suck fuel from intake vacuum? No I havent changed plugs. I pulled them, and wiped them off. Was checking for gas smell in cylinders, no fuel getting in there. It isnt sucking gas.
 

Scott Danforth

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Soo,,its just supposed to suck fuel from intake vacuum? No I havent changed plugs. I pulled them, and wiped them off. Was checking for gas smell in cylinders, no fuel getting in there. It isnt sucking gas.

no, that is what the fuel pump is for. however you need to pump the bulb firm. if after that you still are not getting fuel to the cylinders, your float level may be off (you did say you rebuilt your carbs).

I like to mix a bit of pre-mix in a quirt bottle (2-stroke version of starting fluid) to see if the motor will fire
 

DavidMoore

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What does the manual say about chokes / enricheners. Even if the start procedure is not explicit, there should be a description of the choke / enrichening system and how it works and what to do to test it.
In any case make sure it's working because it will be very difficult to start without it.

Note I don't really understand how the the guy you bought it from said to raise the high idle lever about half way, push the choke to start, but you say you can't activate the enrichener. For me "pushing the choke" and "activating the enrichener" are 2 ways of describing the same thing. Usually performed by pushing in the key whilst cranking the engine.

Normal start procedure.
Primer bulb nice and hard.
Fast idle lever 1/2 to 3/4 up. (could even go all the way up but then it might start very fast)
Turn key whilst pushing it in.
Keeping the key pushed in crank for about 10 seconds. - should fire right up.
Wait 20 sec's between cranking cycles to protect the starter motor.

Once started lower the fast idle lever to keep the RMP under control, keep lowering until fully down. If engine stumbles during the process give it a squirt of fuel by giving the key a a quick push.


If your sure your not getting fuel, also:
Check carbs are completely closed when trying to start.
1971 engine, how are the fuel lines? If you rub them and get black hands replace them, old lines don't like modern fuels and failing fuel lines can very quickly block up the carbs. You may have to clean the carbs again if the fuel lines are old. Every one of those tiny holes needs blown out with compressed air and need to be be spotless.

Re cold starting issues, quick cheap and easy fixes that seemed to work for me :

New plugs
Strip, clean and rebuild starter motor (made a world of difference to cranking speed).
HT leads installed with di-electric (non conducting) grease at all connections to keep the moisture out.
 
Joined
Mar 28, 2016
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My control box does not allow the key to be pushed in. It has a choke button, but it operates a conventional choke. Its a simple solenoid that pulls a pair of choke plates over the mouths of the carbs. All the manual sais about chokes and enricheners is the operating principal, and how to service/ replace. Really a sh** manual or perhaps I should have bought the paper version. Im guessing that original paperwork might have included a seperate operators manual.

I tried spraying pre mix into the mouths of the carbs, but seriously? Theres no way to get it in there unless a spray tube can be employed. The front plate is very close to the carbs, so spraying pre mix from a bottle just makes a mess. Im not sure though, not sure how much gas it takes to get a cough or a sputter. Surely some gas got in there from the spray bottle?

Anyway, going to pop the top structure off again today and see if theres an enrichener solenoid on the port side,, and check for spark. I hate to just keep cranking it knowing that there is no fuel to lube the cylinders, and hope it will fire.
 

merc850

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There is no factory enrichener on that motor, sometimes this works: tip the motor on to the tilt lock and pump the ball until gas flows out of the carbs then tilt it down and lift the cold start lever push in choke and turn key. are the choke shutters closing all the way and are they close to the carbs?
 

GA_Boater

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Have you done anything to the motor since last season? You don't need to squirt gas in the carb to start this motor.

It's time to start with the basics.

Check compression and spark, along with the choke check out merc850 has. The choke needs to work to start a cold Merc.
 
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