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Discussion Starter · #1 ·
Hey Everyone,
So I have an '86 750 with 54,000 that was having a hard time starting. So I put in new spark plugs. NGK DP8EA-9. Guy at Cycle shop said we needed to gap plugs ecause they werent gapped, which we did at store. to .032 I think. (Don't they come gapped???) He said they burn a bit colder. He didn't have the "better" hotter burning, Iridium DPR7EIX-9 that everybody talks about. So here is the problem. Boy She has never started so good!!! One easy push of starter and vrrrroom! Idles great. But when I get going about 35-40 she starts to cough, lose power, just doesn't get going at all! Especialy up a grade. Also a bit of moisture in left front cylinder. (Gas/oil??? very slick...not water.) Any help would be greatly appriciated. This is my only form of transortation and can't affored to be down. I was thinking about putting old cleaned up plugs back in and see what happens. When they were in at least she had plenty of power on freeway.
Thanks again!:smiley_th
 

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Just a guess, but hard time starting could have mostly been because of the carbs. Do you run Seafoam in with your gas on a regular basis? How did the old plugs looks when you took them out. Your old plugs could have been fouled out do to carb issues.
 

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Next time look into NGK Iridium plugs. You'll be happier all around
 

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Discussion Starter · #4 ·
Thanks...

I know this...but I,m looking for an answer the reason for it running rough on the road. Why does it start so easy and then run rough? is it because of bad plugs or should I look elsewhere for problem? I ran fine on the road before I changed them but didnt start so easy.
Thanks
 

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Giggity!
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I would do as you said, "replace the originals" & see what happens. If it's the same then you can rule that out.

The vent tube that runs to the right ear can cause the symptoms you're describing. Check to see if it's bottomed out.

Have you done anything to the carbs? Like Shark suggested, Seafoam is great stuff to run regularly. It does wonders for keeping the carbs clean.
 

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Your main jets are probably dirty or plugged. The bike runs off the pilot jets until about 3000 rpms then the main jets kick in. Sounds like you are not getting enough fuel above 3000 rpms. Try some SeaFoam.
 

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ass hole extaordinaire
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when i replaced my plugs the first time i got the regular ngk plugs and gapped them at 35 and i had the same issue try gaping them around 40 to 45 and see what happens

at 32 to 35 the spark is hotter because there is less distance for the arc to travel to ground however it is a smaller spark for the same reason gaping them wider creates a longer arc allowing more efficient fuel ignition and a cleaner burn but if you gap too wide you have too weak of a spark or no spark at all
 

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Crap, I WAS in 5th gear.
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What is this liquid in your front cylinder? If your plugs are wet, they may not be firing under load. At this point it could be anything from a lean mixture, weak coil, to a head gasket leak. If the old plugs improve things, all you will know is that the plugs are performing differently-- you still need to make a list of things to check off.
 

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Zippy

Don't know if this helps any but I was having some weird stalling issues at take off that I could not pin down. I changed the plugs out to the NGK Iridum's DPR7EIX-9 and they cured all the issues I had. The nice thing with them is they are already pre-gapped no messing with them.
 

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if it were me....I would clean up the old plugs and put them back in with the correct gap since you mentioned it seemed fine with them in place......then run SeaFoam in the engine and see how it runs. if it runs fine, then you at least have a known starting point to work with.

After running the cleaned up plugs a while, check each plug to see if they are running lean, rich, or fouling.

If all is well, then go ahead and put the new plugs in with the recommended gap set. from that point you repeat the process of reading the plugs before you make any adjustments.

If you have any oil showing up, then you need to address that issue.

If the plugs are wet with fuel, you are running too rich. This can be a number of things from a clogged air filter to an electrical issue with the coils or plug wires.

The point to all this is that even though there are a lot of good suggestions being thrown at you, you need to attack any troubleshooting with a measured response.....one step at a time to eliminate contributing issues one at a time. If you go ahead and change air filters with a different type or oil along with different plugs and so on...you will never know which item is contributing or causing the problem.

Patience grasshopper......lol
 

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...another plug thread...*siiiigh*...I been runnin stock NGKs w/o issues...but my exhaust and carbs are finely tuned to each other (not by ma Kaw, by me)....
Do what KC said...check for fouling after awhile...that will indicate whether or not you fuel/air mixture is too lean or rich....the fix is yet another story...
If front and rear appear "close" to each other, then its a mixture thing...if just one is screwed up, its an ignition issue.......usually, anyway....
 
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