Mercury 45hp 1988 lumpy and not running well

[sparky67]

Hi,

I have a Mercury 45hp 2 stroke 1988 outboard on the back of a dory. It's not been used for a good 10 years. It wasn't flowing water through (didn't give it long before I switched it off) so I sent it to the shop and it had a new waterpump/impeller fitted. Water's fine now comes out well. However I took it on the water today it starts fine (first time) and it idles well although it's a little lumpy but when you hit the throttle if holds back before getting going and it doesn't feel like it's hitting full throttle just feels like it's holding back all the time.

Any help would be appreciated.

Thanks

 

[This_lil_fishy]

Re: Mercury 45hp 1988 lumpy and not running well

Common process for an engine the sits that long:

1, Check plugs, make sure they are firing and not fouled (quite likely fouled)
2, Rebuild carbs, replace all fuel lines, rebuild fuel pump.

Shouldn't cost a lot of money, maybe a couple bills for all the parts.

Ian

 

[sparky67]

Re: Mercury 45hp 1988 lumpy and not running well

Common process for an engine the sits that long:

1, Check plugs, make sure they are firing and not fouled (quite likely fouled)
2, Rebuild carbs, replace all fuel lines, rebuild fuel pump.

Shouldn't cost a lot of money, maybe a couple bills for all the parts.

Ian

I've checked plugs and cleaned them they look fine. I think I should get a manual before I start messing around with the carbs. I've seen the SELOC manuals they look pretty good. I was a little concerned this might be an electrical fault. I've heard about the stator (???) going wrong.

I've had the fuel lines from the fuel tank to motor replaced.

I've simple mechanics knowledge manly on motorbikes.


Marc

 

[DutchMerc]

Re: Mercury 45hp 1988 lumpy and not running well

I've had the same problem on my Mercury 402 Thunderbold. It has not been in the water for at least 15 years, and was running well at the time they put it to rest. I tried to start it after rebuilding the waterpump, carbs and new plugs, and it started just fine. When i took it out, it didn't have the power. Turned out the switchbox went bad over the years and had to replace it. I sure hope you have more luck than i had...My tip: check if all plugs are firing, you'll lose a lot of power when running low on cilinders...

 

[sparky67]

Re: Mercury 45hp 1988 lumpy and not running well

This turned out to be the carb in the end. They were stripped and soaked in carb cleaner and it all worked fine afterwards.

Thanks. Marc