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White Smoke

"ran it again today and had po

"ran it again today and had poor results, Bogged down after ten minnutes and would stall out if i didnt give it enough throttle. Later it would either start for about 4 seconds or i would need to floor it to get it to turn over, and it seems as the engine cools it runs a little better but still must be a Big problem.

I also checked the new plugs and they are not steam cleaned they look black.

And a few questions would be...

A neighbor told me it might be running rich and we discovered the ignition coil wire was all gucked up so I replaced the ignition coil and am waiting on the wire butcould this all be a symptom of running very rich??

and what Im leaning towards is a cracked head at worst but what im really hoping is that it isnt a cracked block, anyway i could tell besides checking the oil (which looks good and at the right level for weeks now)??

...and i know i need to do a compression test too just gotta get the gauge"
 
Since the tach is dead did you

Since the tach is dead did you disconnect it from the neg. side of the coil? It will interfere w/the coil.

Black plugs means mixture is too rich or combustion is incomplete due to defective spark.
 
"Steve, would it run fine for

"Steve, would it run fine for 5 minutes or under power than die out if this were the case, and i know rich would explain smoke but idk if itd be white, ive seen rich 2 strokes puff blueish smoke when the mix is too high

And Guy i dont exactly follow on the the disconnecting the tach from the neg of the coil...

PS Thanks once again you guys are great help"
 
"If you can reach disconnect t

"If you can reach disconnect the purple from the back of the tach,

blue smoke on 2 & 4 strokes is too much oil, black is to rich, white is steam aka water ( personal experience )

I had crack in my inline 6 int/exh manifold and exh was burning off the water, then on another manifold on the intake side (like a 4cyl 120/140) which also caused miss fires and steam cleaning of the plugs, and would be tough to run and can bend push rods(I still have it here somewhere..)."
 
"Well that sounds like somethi

"Well that sounds like something that could of happened, i have single point drain which is one of the worst drain systems and there is no other drain plugs on the manifold, i always try to just put antifreeze solution in it but who knows..

would i have to take off the manifold to look for a crack??"
 
"unfortuneately yes thats the

"unfortuneately yes thats the only way is to take the manifold off, I guess you could start with inspecting the elbow

the one valve does drain the manifold and the block unless theres a blockage.

What was the outside temp when you were running it ?"
 
Remove and tape the gray wire

Remove and tape the gray wire from the back of the tachometer. That wire is a direct connection to the neg. side of the coil. Don't disconnect the wire at the coil since it is needed for the shift interrupt switch.
 
"mike, the easy way to see if

"mike, the easy way to see if the manifold is leaking is to run at idle, let it get warmed up, then stop and pull the plugs and look at the color and look for droplets on the electrode ends of the plugs usually where the threads are and lack of tan or brown coloring on the plugs mentioned earlier is steam cleaning from the engine burning water in the combustion chamber"
 
"Mike , when were the risers a

"Mike , when were the risers and manifolds last changed. If these are the originals, then the issue of steam is comming from a leaking manifold into the engine. If you run the engine at idle, and wait till it warms up, you should be able to place your hand on the tops of the risers (they will feel warm, not scalding hot) If you cant place your hand on the risers (scalding hot) then there is an issue with the exhaust, that is where the steam is comming from."
 
it is the original manifold an

it is the original manifold and when i was able to keep my hand on it for about 5 seconds before it got too hot. Is this what you mean by placing my hand or should i be able to keep my hand there for longer?

Its been rainiing on and off so i didnt get a chance to get under the dash and disconnect the tach negative... But would this result in white smoke anyway? I wouild have to think that the stalling out and smoke are linked no?

Also still waiting for coil wire so im using the old one with some corrsion but i tried cleaning it up best i can though...
 
"With the engine warmed up,you

"With the engine warmed up,you should be able to keep your hand on the risers with out having to remove them.If you cant then the riser and manifold may be in question. If this is a salt water boat then the risers will last 3- 4 years, manifolds a little longer. If you have concerns about steam, pull the riser and look and see if the manifold passages are clogged. Let me say even if they look as if they are open, the interior surface may have thin walls and alow water to enter the engine.You may try just replacing the risers and see what happens.However 8 year old risers and manifolds have lived out their life expectency. Stem means that the water is being burned with the fuel, over heating while increasing RPM means that the engine can not pass water through it in such a way that it maintains a cool temp. Check the thermostat and see what temp range it is. If it isa 142 then 175 is to hot. 160 degree thermostat should run in the 165 range.If you have any questions about the risers and manifolds change them. A leaking manifold can cause you to have to replace your engine. $450 now or $4000 later."
 
ok first off when you say rise

ok first off when you say riser it is the elbow right of the manifold right?
The boat has only 50 hours on it but prev owner wasnt too knowledgble and probly never flushed it much so i can see that..

and the tstat in it now was just replaced and its a 140 engine runs around 160 (also onyl goes up to about 165 while under power)

now the big question is after i chekck up on all this whats the chance id be throwing money into an engine that may be already shot?
 
"Why do you think the engine i

"Why do you think the engine is "shot" 160 is not hot, if it hits 190 -200 then its hot. Risers/ elbows the same thing. They should be warm to the touch not so hot as you can not leave your hand on them. Has this boat ever over heated? run in the 250-260 degree range? To check the heads you need to do a compression check and see if there is an issue there. There are merc service manuals available ask Bondo he will direct you to where you can find them.If the boat was never over heated then there should not be an issue with the heads.Is this boat FWC? If it is there may be a problem in the heat exchanger. You said that you have replaced antifreeze, if so this is a FWC engine, look into a leak from the heat exchanger or a poorly operational one. This may be the cause to the problem."
 
"ok first off when you say

"ok first off when you say riser it is the elbow right of the manifold right?"

YES; it's not getting enough cooling. Did you replace the impeller? 160 deg. temp from a 140 deg. T'stat. is saying not enough water is flowing to cool the block. Hot water is making the exhaust elbow too hot to keep your hand on it. Either the elbow water passages are plugged
and/or the impeller is not pushing enough water. Start taking it apart instead of just talking about it or you'll never get to the root of the problem(s).
 
"Ok so i finnaly got some time

"Ok so i finnaly got some time to take off the manifold and found no evudence of cracks or blown gasket. I hooked up a garden house and clamped it to the fitting on the manifold and ran water through the manifold and the elbow together only to discover that there was a good amount of flow coming out the elbow.. But this confused me so while I was backchecking everything i noticed i had placed that plastic piece atop the thermostat wrong when i changed that. This is hard to explain but i had it so water coming from the pump could enter the housing but i had blocked off current that sends the excess cold water over the thermostat and out the manifold. To me, correct me if I am wrong, this would cause the manifold to become extremely hot and create steam.

Now i did not get a chance to run it because i didnt want to put everything back together but could anybody tell me how strong off flow has to go through manifold and elbow? it seems like i get almost the same pressure as a garden house without a nozzle the way i rigged it up..

also a mechanic neighbor told me the plugs were not steam cleaned but showed evidence of running lean. He noted that the one closest to the carb was blackest and the one furthest was whitest."
 
oh and JOe the boat is standar

oh and JOe the boat is standard cooling i meant i put antifreeze in it for a night when it would freeze because i couldnt drain it.
BTW now i have the drain opened up a little.
 
"yes, this could be the cause

"yes, this could be the cause of the elboe( riser) getting extremly hot. Suggestion, some have done this. Inquire at a radiator shop or an engine shop about the cost of boiling out the elbows and the manifolds. If the price is reasonable have it done. This way you will have confidence in the fact that the passages are clear. If the charge is the same as or near the cost of a new exhaust set, then buy a new set or replace the 50 hour set back on the boat.Also, when replacing the elbows and manifolds back, you must purchase new gaskets. Use some permitex aviation sealer on the manifold top where the elbow sits. Make sure that you have the correct gaskets, you can be sure by keeping the old ones as a guide."
 
"the plugs...showed eviden

"the plugs...showed evidence of running lean...the one closest to the carb was blackest and the one furthest was whitest."

Change the carb. base gasket to a 1/4" or so thick one to improve atomization of the fuel/air mixture. Possibly needs a set of plug wires.
 
I have been waiting over a wee

I have been waiting over a week for plug wires the one from the ignition coil to dist was coroded but not terribly bad. IM guessing that when the engine runs for about 5 minutes that wire doesnt work as well???
other than that the carb is at factory settings on both idle speed and idle mixture and i adjusted as in a clymer manual
 
"Easier to just buy a complete

"Easier to just buy a complete set and put that on, maybe keep the old plug wires for emergency"
 
mike by adjusting the carb to

mike by adjusting the carb to factory specs isnt always the answer for adjusting one properly.GUY has a formula that i used and it worked way better than the factory spec setting i take it that this is a points and condenser system if so replace the condenser on the coil and points they seem to fail when there bad when it heats up
 
"If your only smoking at the d

"If your only smoking at the driveway, check following.
1- hose water pressure.Too little water=steam
2- Drive is down and bow of boat is higher than the transom.
3- If exhaust elbow (riser) is clogged where the exhaust hose connects, it will create a hot spot where there is a lack of water flow which will cause the little bit of water trickeling out to burn and steam on the way out.
4- Make sure the impeller is in good condition.
5- If you remove the exhaust elbow for inspection, look inside the hose as well for any blistering or delamination."
 
do a leak down test an compres

do a leak down test an compress test as my volvo had a light white smoke from it an the rings were done
 
So finally got everything back

So finally got everything back together and turns out it was indeed the plastic sleeve blocking waterflow and/or the wrong thermostat the dealer gave me. Engine still runs a little crappy at higher speeds (misfires maybe) so im lokoing to replace the dist. cap and rotor..

all spark plug wires are replaced as well as:
Tstat
impeller
cleaned out manifold and elbow
I disconnected the tach
and the ignition coil was just put on

IM probly goingh tot start another post if i can't find the problem THanks alot for all whove helped
 
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