99 Mercury 4 stroke- Carb adjustments without gauges

[Outboard Mike]

Been working on a friends 99 40hp 4 stroke motor. It was in a no start condition when I started working on it. It had not been run much for the past few years and had some old gas. I replaced fuel tank with new gas and quickleen, primer pump, fuel lines from the motor to the tank, fuel filter and the fuel pump(was bad). I took off the fuel lines on the carbs and blew out all the old gas that was in the carbs with a compressor. I got the engine running but it would stall on acceleration. I tried to adjust the idle screw and carbs by pinching off the top and bottom carb lines. I don't have the gauges to sync the carbs and my friend needs the boat next week. How can I adjust the carbs without the gauges?? I do have a manual and it does not show adjustments without gauges,

 

[Faztbullet]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

Well ya cant do it on a hose as it needs to be in a barrel or lake for backpressure and there are a lot of passagesways that if blocked with some varnish will cause it to bogg.

 

[jimdd810]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

I agree you need to remove the carbs and clean them and chase all the passages with a syringe full of alcohol. That should take care of your problem. Then if you havnt messed with the adjustment screws you should be close. You can buy the gauges your in need of at any motorcycle parts store or even autozone or such.

 

[Outboard Mike]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

What about Seafoam? Do you use it very often? I'm hesitant about pulling the carbs because the carb kits are $60 each and I still don't have the gauges.

 

[jimdd810]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

sea foam wont take the place of a complete overhaul. You will save your self time and money in the long run by doing it right the first time.

 

[Outboard Mike]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

I'm ready to take the carbs apart but someone messed with the linkage and I can't just take them apart and put them back together because they will need to be syncd. How can I make a sync tool with gauges and lines from harbor freight or autozone?? Any directions on how to do this along with the process for tuning and syncing would be great.

 

[jimdd810]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

you can buy the sync guages for about the same price as making your own

 

[Outboard Mike]

Re: 99 Mercury 4 stroke- Carb adjustments without gauges

Any idea what kind I should get and where??