310 top end cutting out, Dyna CDI trouble?

[Iliketogofast]

I just got my motor back together and I took it out and the top end is cutting out a little. I called up ESR and he said it sounds like ignition, so I called Dynatek and the tech support guy sounded like a retard. He just kind of mosied me around.

He asked what plug wire I had and I said stock and then he said it may be the wrong resistance. How is it the wrong resistance? Then he kind of paused and I asked what to do and he didn't answer and I suggested maybe I should get a new wire and he said "Yeah, maybe."

I don't think the wire is the problem.

There are a few out of the ordinary things I am doing - one it was a BR8 plug where reccomended was a 9, and the other was running the Dyna CDI. It started raining so I hadn't had the chance to try the stock one, but it is for an 88 bottom end because I had an 88 bottom before so I don't think it will even work.

Any suggestions to get this CDI to work?

[Aceman]

Originally posted by Iliketogofast
Any suggestions to get this CDI to work?

Yeah, swap in a stock CDI first to see if it's really the culprit.

Go through the electrical troubleshooting checklist posted above.

[Iliketogofast]

Well the stock CDI is from an 88 bottom and I've since switched to an 86. Will it still work?

[Aceman]

My mistake, I read right over the part where you said it was for an 88. I don't know, you'll have to wait for someone else to answer that. Service Honda shows two different part numbers. But if the connections match, I'd definitely try it though AFTER I checked all the other electrical components.

[my88r]

could it be a improperly gaped plug. i know those big bores. you should have a different gap then stock.

[Iliketogofast]

Well it stopped raining, if anybody knows the correct plug gap I will try that. Too late to call ESR and get it, if nobody has it I'll have to wait until tomorrow.

Also I'll note that it runs fine in the rest of the range and even revs high fine when in neutral.

The cutting out is more like a sputter that stops it from getting into the real power. Instead of taking off like a rocket it just sputters and goes sort of quick.

[machwon]

Yes, the CDI's can be switched. Run the plug gap at .020" and start with a new plug. Check and make sure all electrical connections are tight. If you use the top aluminum piece on the spark plug, make sure and tighten that down as well before you install it. Stock CDI's can run real well.

[Iliketogofast]

I swapped the CDI and it ran fine for a little bit. I took it down the road with no problems then turned around and went back to the house and killed it so I could put my front plastics back on.

Once I got the plastics back on and went to kick it over it started but it ran like garbage and would barely stay running. It died and I kicked it over again and tried to put it into gear but it just bogged down and died.

After that I couldn't get it to start so I swapped CDI's back to the dyna and still no spark.

The weird thing is that my tach, which is an inductive pickup type thing wrapped around the plug wire, shows RPMs when I kick it over. There must be something there, but I don't see it when I test for spark.

Also, right after it died and wouldn't start there was a short period of time where every once in a while it would backfire loudly when you kick it over. It would never try to start, only a loud backfire or a weird sound through the intake.

Right now I have the gas tank off and am getting ready to go out and run through all the wiring. The way I see it something has to have been loose and come disconnected when I put the front plastic on.

Any suggestions are welcome, I'm baffled here. I'm not the greatest electrician.



Edit:

I just got in from running through the wires. Everything is connected. Now I'm totally stumped.

[Iliketogofast]

I tested everything mentioned in Beerock's writeup and everything is good but the Pulse generator. It didn't show up at all. However I don't know if I tested it right.

It says on the writeup to disconnect the pulse generator. I disconnected the wires, which to me is "disconnecting" the pulse generator, and I tested on the side that comes out of the engine. I tested with the ground on my frame and the red wire on the multimeter on each of the blue/yellow and green/white wires, and there was no change on the screen as if I hadn't done anything.

I was confused though if when he said "Disconnect the pulse generator" he meant to disconnect the actual unit from the engine.

Edit: I just went out and tested with one wire on the blue/yellow and one on the green/white and it was within the specifications. If that's the right way to test it, everything is fine.

I can't test the regulator because the engine won't run.

So if everything else is good then if I'm correct that leaves only the CDI and faulty wiring somewhere. I have two CDIs and neither work so that is almost ruled out.

Does anybody know of anything else?

[Aceman]

Try trimming your coil wire back where it goes into the spark plug cap. They can make erratic contact if they're corroded. It can pass a resistance test but when you move it just right it could be breaking contact, it would explain your backfiring also. Something to try.

Make sure your plug hasn't fouled either while doing all this testing.

[Iliketogofast]

I've already trimmed that. I peeled off all the tape and found that there are several loose ends and open wires where a short could happen. I'm just going to order a new harness because mine is just a mess.

The thing is all of the wires have continuity and all of the items in the system test correctly and it won't spark. I think it may be a faulty killswitch, but it isn't old either.

I'm really stumped by this and will probably end up taking it to the shop if I can't figure it out.

[Aceman]

It sounds like fixing your harness is a good idea.

The killswitch simply grounds the coil wire. If you think it may be faulty, just unhook it. A simple continuity check(ohm reading) will tell you if it's grounding out.

EDIT: Almost forgot, your motor needs to reach a certain rpm before you'll see a spark. Pretty hard to kick and watch for spark by yourself.

[dtek01]

I would definitely check out the Dynatek box though. I had one myself recently that would do the exact same thing you are describing.

I sent it in on my bill, they replaced the unit and it did the same thing.

Stock CDI back in and all is well. To me they are a piece. I tried it on my bike and my cousins stock 86' with the same results both times.

Just a thought.

[Iliketogofast]

Partsfish says the wiring harness is discontinued. Is there anybody who sells a new one or am I going to have to settle for used?

By the way Ace, thanks for all your help.

[ringoesroadking]

It is the Dynatek cdi box.
I had the same exact problem with 4 different boxes. Their customer service guys are great. Larry and Angel, Yes I know their names. they have shipped me out so many new boxes, they all ran just like the one you have, oddly enough some ran better than others, but in the end they are the biggest pieces of junk! Not a single good one was shipped to me! My stock box runs fine. The most dicouraging thing was, the low end throttle response was night and day better with the dynatek, until it cut out or "broke up" topend. That is why i sent so many back in hopes to finally get a good one? I thought " they can't all be junk" right? Not the case! They are SHI*
:grr: :(
Fu** y*u Dynatek!

[Buttermilk]

I guess I've gotten two good ones......

Both of mine work great. One on a Banshee, the other on a 250R CR ignition.

[gandgracing]

Just a thought, have you looked at your flywheel to see if its still tight?

[machwon]

In my opinion they are not good bolt ons. If you want to play with the timing and have a way of testing each change you could likely find some gain. If an ATV comes to me without Denso components I begin to question it right there. Most OEM electrical components have the best reliability and usually the best performance IMO.