engine starts and runs fine then wants to bog down

[scdeerslayer]

I have an 83 johnson 200 it runs fine until heated up or cut off after running then it might run fine or it might bog and if given more fuel while bogging it will cut off. If while bogging i play with the throttle it might take off and run fine. It just feels like it is cutting in and out. I have taken the carbs apart, took the fuel tanks out and cleaned, new fuel lines. I don't think the fuel system is the problem cleaned it just to do it. I think it is electrical but I don't know where to start. It runs great in the yard but it seems to sometime idle lower can go from 1000 rpm to 500rpm but it won't bog when given gas. Also would being under a load effect it if it's electrical. It also seems to be getting worse. Any help will be appreciated. Thanks.

 

[jonesg]

Re: engine starts and runs fine then wants to bog down

Put a timing light on it when it doesn't want to run.

Get a spark tester from the auto part store, the adjustable gap type, set the gap to 3/8th inch, remove all plugs and see if you get a blue spark from each cyl.

Do this when its starts acting up, often a powerpack or other elec component works fine until it gets hot.

Eliminate the elec problems first, then we'll look at the fuel delivery.

 

[OzzieOzzieOzzie]

Re: engine starts and runs fine then wants to bog down

I Had the same problem on my 1995 70hp Johnson. Stripped and clean carbs, emptied and clean fuel tank and lines, with not effect. Ended up been the power pack which was playing up when hot.

 

[scdeerslayer]

Re: engine starts and runs fine then wants to bog down

Thanks guy's tested my coils last night and the number 1 coil is bad and number 5 was weak. From what little i know i think the number 1 cylinder is the most important and this could whats throwing everything off.

 

[tashasdaddy]

Re: engine starts and runs fine then wants to bog down

no cylinder is more important than any other. they all have to work equally.

read ethanol and carb cleaning. http://forums.iboats.com/showthread.php?t=299680

 

[scdeerslayer]

Re: engine starts and runs fine then wants to bog down

Well I changed 2 coils and some spark plug wires today. The motor ran great for like 4 hours thought it was fixed ran like new and then had same problem except to a lesser extent. There is another coil that is reading low so I am about to change it now and see what happens. All in all a good day caught a 30 1/2 lb striper and the boat got me back to the landing so going to go tinker with it some more if anyone has an idea please help me out. I heard it could be a stator but not sure what the stator does. Now naming the boat who knows because who knows if we'll get back.

 

[emdsapmgr]

Re: engine starts and runs fine then wants to bog down

Jonesg has offered some good ignittion advice. Check the ignition wires for spark when the engine starts to act up.

 

[jonesg]

Re: engine starts and runs fine then wants to bog down

The auto part store gets a laugh out of me, I buy 1 headlight, a few days later the other headlight burns out, they say always do the lot.

Its kinda like changing 5 sparkplugs instead of 6.
I think its the same with coils, once they start cracking they're all well on their way outta there.

 

[scdeerslayer]

Re: engine starts and runs fine then wants to bog down

Thanks guys for the advice the last post I had put up I had had a few drinks, anyway. I had a friend of mine go out on the water with the boat the other day and test for fire when the engine acted up and there were cylinders not firing. We had to take it out on the water because it wouldn't act up in the driveway. After 4 hours of running around fishing it finally messed up which unlike before if I gave the engine more fuel it would catch up and go instead of cutting off. I had already bought 3 more coils for it so we replaced them at the ramp and it ran like a champ. one of the coils was actually cracked on both ends and somewhat melted on the back side. So thanks for all the help here and we had a great day ended up with 4 striper 19# 31# 36# and a 39#