Gas Engine Tune Up - Owner Performed

[n36511]

Thinking about doing my own tune-ups on my crusader 454 tbi engines. Can someone tell me what on a gas engine gets replaced or adjusted during a shop performed tune up? Spark plugs, spark plug wires, etc? Also, I believe my engines have electronic ignitions if that changes any of the steps.

Thanks,
Scott

 

[DavidM]

There is little to do for a "tune up" on an electronic ignition, electronic fuel injected engine run on unleaded gas.

Unleaded gas has let spark plugs last 100,000 miles on cars and several thousand hours on a boat. There is nothing to do to electronic ignition (no points- I haven't touched any points in 30 years) or on electronic fuel injection systems.

If you do have a carburetor there is nothing to do proactively. Even if you have a carburetor and ethanol fuel has caused rough running or whatever then disassemble it and soak in a can of carburetor cleaner overnight and it will be good.

For my own car with modern electronics, I change the oil, oil filter and air cleaner filter periodically and forget the rest. I would do the same for a boat engine.

David

 

[Larry H]

If you do it wrong, you will have a bomb!

Marine gas engines require marine parts. Replace gas filters and spark plugs with original equipment parts only. Do not cut into any fuel hose or steel fuel line. Marine carburetors (if equipped) are special, do not substitute with automotive parts.

Have a qualified marine mechanic perform the tune up and watch and learn, then see if you can do it next time.

That's my opinion as a retired marine engine mechanic.

 

[sum escape]

Gassers and sparks do not get along well. Be sure to regularly change the spark plug wires as deteriorated wires can be an explosion threat. Easy to do and cheap insurance.
Other than that not much other than fuel and air filters as others have stated.

 

[n36511]

Ok so it appears I have distributor cap and rotor. Prob need to replace those as well? This is the first step in troubleshooting a problem I think I have. Both engines emit a nice sheen of gas on the water when running at idle...almost like unburnt fuel. Owned the rig for 2 years and figured a tune up was the first step in determining what is up.


Sent from my iPhone using Trawler Forum

 

[kulas44]

Well, TBI, so we can stop talking about carbs, aint none. A tune up (change plugs, wires, dist cap, rotor, filters) may help your problem but probably not. Does it have a miss at idle ? A bad plug thats not firing could put a sheen on the water but a miss would be evident. Try pulling plug wires one at a time, looking for reduced rpm. A bad temp sender (not sensor) will make the ecm run in "choke" mode, causing more fuel to be injected. Does it use any oil, bad valve guide sealing can cause oil to be pulled out during high vacuum (idle). Perfect Circle seals usually fix that, but are more involved than a tune up. I would start with changing plugs and wires/cap/rotor. Then do diagnostics.

 

[n36511]

Thanks for the tips. Engines both idle very smoothly and no oil burn. Guess I was thinking that if plugs were fouled it would cause some fuel to not burn.