no power wide open throttle

[fordmonsta]

i bought a 70 johnson stinger motor from a guy at work, had been sitting for quite some time, took carbs apart and cleaned the crap out of em new needles and seats floats and all, now it runs but not well, it will start just fine and idle great out of the water but when i put it in the water it wont even idle and is hard to start, also under full throttle it is a turd, it wont gain rpm with a load on it like it should, runs 7mph wide open, now it did run good for about a minute the oither day, and it would fly, but for a minute is all, i had a bad stator under the flywheel and it would not start at all, i changed that and it runs like i said, but my overall question i guess is would a bad rectifier cause it to be sluggish? i took the carbs back off again tonight and went through em and they are spotless throughout floats are set right and all, what about a bad power pack? what are the symptoms of that getting weak? the fuel bulb stays tight when you are running it also the motor number is 70eslr74m

 

[boobie]

Re: no power wide open throttle

Before you go any further, check the compression on it. Then check the spark which should jump a 7/16 " open air gap on a spark tester.

 

[emdsapmgr]

Re: no power wide open throttle

Possible you only have spark to 2 of the 3 cyls. May seem to run fine on the trailer on 2 cyls. You need all 3 cyls firing when the engine is floating in the lake-in gear. Weak ignition components tend to fail once the engine heats up to normal operating temps. May run fine when cold, then not-when fully warmed up. Warm it up well-then check for spark on each plugwire with an inductive timing light. Could be the power pack, timer base or bad coil. You can swap the coils for testing purposes. The rectifier is part of the charging system, not part of the ignition system. You can check this website for ignition troubleshooting information: cdielectronics.com

 

[fordmonsta]

Re: no power wide open throttle

i have checked the spark with timing light and they all show to be sparking, also checked the total timing wide open seems like it was 32 or 34 total i cannot remember but one of the two, about 4-5 idleing, i did a compression check also two of the cylinders were 120 and one was about 108 the spark air gap test also tested good, it'll jump about a half inch gap with a good hot spark at least when i checked it in the shop, i will look into the cdi electronics troubleshooting also that has been posted here, anything else yall can think of let me know and thanks for the help so far,

 

[Chinewalker]

Re: no power wide open throttle

The 108 to 120 gap is on the very outside edge of acceptable, but probably not enough to cause it to drop a cylinder.

Next time you run it, under load, try toggling the choke and see if it picks up... That would indicate the (common) mid-range bog that many of those older triples had. They had a fix for it that required rejetting the carbs one size richer.

 

[fordmonsta]

Re: no power wide open throttle

well, i took it to the lake today, only couple miles over there and back, anyhow, i disconnected the rectifier and no change, now if i lift the motor up almost out of the water and nail it get the rpms up and drop it back down it runs somewhat ok, will maintain a steady 20mph if i do that until i trim the motor all the way down then it bogs, and starts missing with the extra load on the prop, what would i be looking for as far as the timing plate goes? it moves freely as it is but is there anything else to look at on it, also is there a way to test the powerpack, the damn thing is hard to start in the water also, out of the water it will crank right on up i'm kinda at whits end on this thing, i've done about all i know how to do thats why i'm here asking experts, also i wrote teh wrong timing on one of my posts earlier was thinking of my racecar, the boat has 26 total degrees wide open

 

[emdsapmgr]

Re: no power wide open throttle

You've run it enough to insure the engine is fully warmed up. Does it still have spark then? Any engine will struggle once the exhaust is buried 20" underwater. When it's in the lake and in gear, engine tucked "in" (all the way down) and it seems to be lugging a lot, you can do a test: with a set of insulated pliers, pull off the top spark plug wire. See what happens. Replace the wire, then pull the middle plug wire, etc, then lower. Once any plug wire is pulled off, the engine should still run, but labor/struggle to keep running. If you pull one of the 3 wires and the engine shuts off, that specific cyl may not be contributing it's fair share to the running of the engine.

 

[fordmonsta]

Re: no power wide open throttle

well, i tested the choke deal yesterday on hte water, it killed it, so when i got home i tested the timer base with an ohm meter, from white to black and white to black, one side said 7.4 ohms the other said 14.8 ohms, does that sound about right or? thanks for all the help

 

[trendsetter240]

Re: no power wide open throttle

Here's a super easy test that will help identify the issue.

Get yourself a can of aerosol carb cleaner and start the motor with the cover off. Spray the carb cleaner into the top carb and observe the results. Repeat with the middle and lower cylinder.

One of three things will happen when you are spraying the carb cleaner into the carb.

A. The engine will bog down. (Cylinder is getting fuel and spark)
B. The engine will speed up. (Cylinder is not getting fuel but is getting spark)
C. The engine will do nothing. (Cylinder is not getting spark.)

 

[emdsapmgr]

Re: no power wide open throttle

You can find ignition troubleshooting electrical values for your engine inside the factory service manual. Or check out this website: cdielectronics.com. Look for your year engine.

 

[fordmonsta]

Re: no power wide open throttle

finally got it doing right, thanks for yalls help with it ended up being that it had too much timing advance, somebody had set it at 27 degrees and its only supposed to have about 18 in it, runs like a champ now, thanks again