1988 75 HP Mariner - Smoke on start up with warm up lever

[hagcel]

When I cold start the motor I typically have the warm up lever set a little fast than normal idle. Then once the motor start I will rev the engine with the warm up lever. When I push the warm up lever all the way back down the motor will smoke a bit have a quick stutter then it idles fine. Once the motor is running a few minutes I can rev and lower RPM back to idle with no issue.

Is this normal or is there something I should investigate?

Also sometimes - but this is not consistent behavior, I'll run the motor out of the lake then we will sit and drift or troll for a few hours. When I go to start the motor again, sometimes it starts right up, other times it doesn't want to start at all unless the warmup lever is in max position. Once it starts there is plenty of smoke. Any idea what that means?

edit: I should add that I never have to do this from a totally cold start / first start of the day. Only after it has been running on the lake

And one last question...

I recently installed a new gas line. I have a 22 gallon tank below the deck. I bought a new Merc lined cut off one end as I have a fitting on the back of the boat where it connects to the gas tank. The hose I bought was 8 foot. I really only need it to be a few feet. Should the gas line be as short as possible or does it not really matter?

Thanks for any thoughts or suggestions!

 

[racerone]

What ratio oil / gas are you using ?-----What oil are you using ?

 

[hagcel]

No Title

it's an oil injected motor. I'm not sure what the oil is. I bought the boat this fall and the oil was filled at a shop.

for the problem of getting it to start on the water i was able to talk to a mechanic and he said it sounded like a fuel issue. he said the easiest thing to check is the anti siphon valve. he said there is a little ball in there that can get stuck.

I'm thinking the anti siphon valve is the L shaped connector on the middle hose? Anyone ever disassembled the anti siphon valve?

http://s26.postimg.org/wlelicndl/IMG_3191.jpg

 

[GA_Boater]

What could be happening is some of the gas in carb is evaporating after shutting off a warm motor and sitting for a while, so the oil is concentrated in the carb leading to the need to raise the warmup lever more and the smoke.

The anti-siphon valve is the hose fitting in the 90 degree fitting.



A new one only costs about 10 bucks and will work for a long time. http://www.iboats.com/Anti-Siphon-Va...iew_id.1693993

 

[hagcel]

thanks. yeah a new anti siphon value will be the easy place to start. any possible solution if the gas is evaporating in the warm motor? just make sure I pump fresh fuel into each time i go to start?

I've always run old, small, evinrudes with external gas tanks so this is all new to me.

 

[GA_Boater]

If the motor runs fine after warm up, I would live with it. Pumping the bulb like a cold start may help.

 

[hagcel]

when changing out gas line or gas line fittings - like the anti siphon valve - should I be using the brush on form a gasket on the barb fittings?

 

[GA_Boater]

Good old Permatex is a good choice for the threads. Nothing on the barbed end.

 

[CharlieB]

You can cut it to fit if you wish, the motor will not care.

Remember these motors are made of aluminum and cooled by the lake water, so they never get very hot. It doesn't take long for them to cool down while fishing so it is no surprise the fast idle lever must be used to help start and warm it up just a short minute.

Since 2 strokes do not have an accelerator pump the idle mixture is set richer than any 'Best Idle speed while in gear. This makes for an very rich mixture running a fast idle with NO load, excess oil will accumulate in the engine during any fast idling, enough that the motor will appear to smoke a bit more than normal until all this is burned out and the motor is again clear.

The fast idle lever is to be lowered as soon as the motor speed begins to stabilize. It is not necessary to keep reving the motor any longer, it only seems to add to the amount of excess smoking.

 

[hagcel]

When replacing the anti-siphon valve should I expect gas to spill out when disconnection the hose? The boat has sat for over a week.

 

[hagcel]

Also I noticed on on the inside of boat, where the motor bolt heads come through from the transom, white silicon rings came off from around the bolts. Can I reapply new silicon to the bolt head or do the bolts need to be pulled and resealed? Is that something a shop would need to do? Or can I just loosen one bolt, coat will silicon and retighten?

 

[hagcel]

No Title

this is the amount of sealant that came off. I'm thinking I can just add a bit of sealant over the boat to keep any water out from the inside on the boat. the outside looks like there is still plenty of sealant.