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Discussion Starter · #1 ·
I'm not too good with these bikes I am way more experienced with older cruisers but my buddy asked for help so here goes. Got an 86 600r a1 ninja that will start and idle fine but has really no throttle response. The rpms go up slighty then it just flattens out and starts backfiring. My initial thoughts were blocked carbs. I cleaned the tank and carbs (which were spotless) checked the float levels (spot on) cvs are moving freely everything seems to be working fine carb wise there synched, idle mixtures dialed in, it idles like a dream. Sometimes it will zip right up like its supposed to but mostly it just pukes and falls on its face. Almost feels like the timing is not advancing. From what I understand the ignitor controls this. Is there a way to check this? Or am I going in the complete wrong direction? Help please!:facepalm:
 

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Discussion Starter · #2 ·
I forgot to mention the wiring harness was damaged by a fire and the po doctored it up pretty lazily. I repaired what I could see but I'm really leaning toward this being an electrical issue based on the intermittency of the issue and the condition of the wiring
 

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Blueghost, or Byte will be along shortly I'm sure, but the other side of things to check is the air side of things. For an engine to run, it needs Fuel, Air and Spark. If one of these are out of whack, then that could also be your problem.
You've eliminated the Carbs, so the remainder of the fuel side of things would be the fuel lines and filter. Maybe also a faulty Petcock in the tank.
On the air side of things, look for blocked filter, perished hoses that are causing a leak etc.
As for spark, well, that should be self explanatory!
 

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Discussion Starter · #4 ·
Blueghost, or Byte will be along shortly I'm sure, but the other side of things to check is the air side of things. For an engine to run, it needs Fuel, Air and Spark. If one of these are out of whack, then that could also be your problem.
You've eliminated the Carbs, so the remainder of the fuel side of things would be the fuel lines and filter. Maybe also a faulty Petcock in the tank.
On the air side of things, look for blocked filter, perished hoses that are causing a leak etc.
As for spark, well, that should be self explanatory!
Plugs are new, air filter is new. Carb boots are in good condition and connected properly. Spark seems to be nice fat purple spark. Petcock was clean and functioning. I have it set to prime to rule out vacuum side of petcock. Like I said randomly it will run fine then go back to ruining poor. It almost seems to run like the spark is not advancing. Only other thing I can think is maybe a coil is breaking up under load. But how can I test that? The bike is my nephews and he doesn't have a lot of money to spend so I'd rather not guess and throw parts at it. Want to be sure.
 

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Plugs are new, air filter is new. Carb boots are in good condition and connected properly. Spark seems to be nice fat purple spark. Petcock was clean and functioning. I have it set to prime to rule out vacuum side of petcock. Like I said randomly it will run fine then go back to ruining poor. It almost seems to run like the spark is not advancing. Only other thing I can think is maybe a coil is breaking up under load. But how can I test that? The bike is my nephews and he doesn't have a lot of money to spend so I'd rather not guess and throw parts at it. Want to be sure.
hey Dave sounds like you have a pretty big mess on your hands. First let me start by saying thanks for being so descriptive on your problem. Secondly it appears that you have a spark issue that is more than likely going to be by a coil or the coil feed signal. To check a coil over plug you need a multimeter to do it properly but I find a meter is hard to use under certain conditions. Each coil over plug has two firing sections. A low side for idle and low tons and the other is for everything else. They both have different resistance loads to check which makes it hard to use it the meter. Especially since a bad coil may only act up at certain temps. However you can visually inspect each one and look for a red residue or color on the coils which indicates arc leaving the coil and grounding out on the motor wall which will cause the bike to have bad response and cylinder loading that once it fires will probably be in the exhaust and will burn a blue to purple color. However a faulty feed wire can do this as well to the coils. Not really a good thing to ride the bike at the moment. Leg me know if you need more info I'll try to help out

twisted throttles bring smiles
 

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Discussion Starter · #6 ·
hey Dave sounds like you have a pretty big mess on your hands. First let me start by saying thanks for being so descriptive on your problem. Secondly it appears that you have a spark issue that is more than likely going to be by a coil or the coil feed signal. To check a coil over plug you need a multimeter to do it properly but I find a meter is hard to use under certain conditions. Each coil over plug has two firing sections. A low side for idle and low tons and the other is for everything else. They both have different resistance loads to check which makes it hard to use it the meter. Especially since a bad coil may only act up at certain temps. However you can visually inspect each one and look for a red residue or color on the coils which indicates arc leaving the coil and grounding out on the motor wall which will cause the bike to have bad response and cylinder loading that once it fires will probably be in the exhaust and will burn a blue to purple color. However a faulty feed wire can do this as well to the coils. Not really a good thing to ride the bike at the moment. Leg me know if you need more info I'll try to help out

twisted throttles bring smiles
That's what I was leaning towards. The coils themselves look clean I can't see signs of arching but the feed wires have all been replaced and doctored up. They're all firing but how well I'm not sure. The bike isn't ridable just been doing testing in my garage. Do you happen to know the coil resistance values so I can prove them out? If not I'll have to pick up a repair manual.
 

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That's what I was leaning towards. The coils themselves look clean I can't see signs of arching but the feed wires have all been replaced and doctored up. They're all firing but how well I'm not sure. The bike isn't ridable just been doing testing in my garage. Do you happen to know the coil resistance values so I can prove them out? If not I'll have to pick up a repair manual.
I don't bud. I'd pick up a manual for the bike usually can get an electronic version pretty cheap. I think I got a r6s version for a friend for like 4 US dollars off eBay at one time. There could be another couple of issues too but the coils are where I'd start. Amy plugs have discoloration in to the head or the porcelain side??

twisted throttles bring smiles
 

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Discussion Starter · #8 ·
OK the coils seem to be testing out OK. Plugs are a little fuel fouled but not crazy bad. I did notice however that there is a bundle of wires leading from the twist grip to the coil hatness that are all melted. Does this bike have some kind of throttle position sensor in the twist grip? That would totally explain the recession I'm getting where it seems like bogging. Im going to repair these wires anyway. Just curious
 

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OK the coils seem to be testing out OK. Plugs are a little fuel fouled but not crazy bad. I did notice however that there is a bundle of wires leading from the twist grip to the coil hatness that are all melted. Does this bike have some kind of throttle position sensor in the twist grip? That would totally explain the recession I'm getting where it seems like bogging. Im going to repair these wires anyway. Just curious
sounds like to me it could be bad wires yes but the plugs color is important to to determine the issue. Describe color on the hot side of the plug as well as the porcelain side. Regardless I'd go ahead and change the plugs change or clean the air filter And if your on the same gass drain it and start with new gas.

twisted throttles brings me smiles
 

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sounds like to me it could be bad wires yes but the plugs color is important to to determine the issue. Describe color on the hot side of the plug as well as the porcelain side. Regardless I'd go ahead and change the plugs change or clean the air filter And if your on the same gass drain it and start with new gas.

twisted throttles brings me smiles
Or diesel....which ever u prefer.....:facepalm:








 

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Discussion Starter · #11 ·
The plugs were a tad wet but probably from it loading up and not firing. The porcelain has a little brown but pretty clean otherwise. Looks pretty uniform.. Looks like a normal running plug. But what I did find as I removed the fairings and started dissecting the engine harness is that several sections of it are burnt, melted, spliced, twisted and taped and just godaweful all around. The rectifier wires were hanging down onto the chain and rubbed though. The ignitor harness was doctored up with speaker wires... Smh the person he bought this bike from should be ashamed of themselves. So i tore the entire harness out and have a used one coming from eBay. I'm frankly surprised the damn thing even started. Once I install the new one I will let you know how it turns out! I'm pretty confident this was the whole problem.
 

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New (used) harness is on and she runs great now! My only question is does anyone have a hose diagram for all these evap hoses???
dave you can go to babbitspartsonline.com. Look up you bike to get some diagrams of the bike somewhat. I don't have a manual but my manual doesn't tell me a thing in routing hoses or cords etc.

twisted throttles brings me smiles
 
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