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Old 08-30-2011, 03:07 PM
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Quote:
Originally Posted by chuck l View Post
28 degrees
Im guessing this is before tdc?
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Old 08-30-2011, 03:15 PM
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I may have missed it in an earlier post, but i have experianced very similar performance, and needle settings before installing a carb rebuild kit, new membranes all around.
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Old 08-30-2011, 06:28 PM
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Originally Posted by luckde View Post
I may have missed it in an earlier post, but i have experianced very similar performance, and needle settings before installing a carb rebuild kit, new membranes all around.
It's brand new. I'd hope a carby kit is not needed. If so the supplier will be sending a new one...
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Old 08-31-2011, 07:20 AM
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Hay guys. Well we had a bit more of a play tonight.. We got it running!!!! but only on one cylinder..

We changed the CDI leads over and the firing cylinder followed the working cap.. We have checked and both leads are sparking, we have set the gaps on the plugs, and tried different plugs. As i said, we have had both cylinders fiering, but one at a time.. We tried advancing and retarding the CDI timing.. No good. As i said its running really well one one cylinder so i'd assume mixes are good enough for the time being. One problem at a time..

Ok, its the xyz 52 twin.. Yes, i know.. Buy cheap expect crap.. bla bla.. There are plenty that are running great, and i wanted to try a twin.. $350 why the hell not..

Ok, the CDI. To the eye it looks like the plugs fire both at the same time.. But im wondering if they are slightly delayed from each other? If so the timing may need a touch more tuning.. I have no idea what its at at the moment, about 40 before TDC.. We looked at the father in-laws smaller 20cc and it fires around the 30 degrees before TDC, but its impossible to set it that low on the 53..

So where to from here? I have contacted the seller, and seems quite good and willing to help. I think i will be requesting a new CDI unit to try..

Any advice / help welcome..

Should have stuck with my initial thoughts and went electric..
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Old 08-31-2011, 07:30 AM
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See if someone you know has a spark tester.Just because the plugs fire outside the cylinder doesn't mean they are firing inside the cylinder.It sounds like you have an ignition problem if only one cylinder is running and one is not and swapping the caps swaps the cylinder.Another way to tell is to use a temp gun,both cylinders should be about the same temp.I don't see a carb problem causing only one cylinder to run.
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Old 08-31-2011, 09:05 AM
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Quote:
Originally Posted by BigK View Post
Im guessing this is before tdc?
Before TDC is correct.
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Old 08-31-2011, 09:19 AM
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Just to clarify, did you say that both plugs were firing at the same time?
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Old 08-31-2011, 04:11 PM
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Temp is easily detectable by the exhaust temps, and yes, one is hot the other stone cold..


And yes it's not a true boxer engine.. Both cylinders hit tdc at the same time... And both plugs spark at the same time.. Well to the eye anyway..
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Old 08-31-2011, 04:14 PM
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We closed the spark plug gaps to .22", might go a bit further and see if there is a difference.
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Old 09-01-2011, 04:30 PM
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Quote:
Originally Posted by Scott Gerber View Post
I know of no way to repair a loose fitting needle properly other than replacment of either carb or needle(s) or all of the above. There is just way too much risk of getting something down in the port from putting some sort of thread lock material on the threads.

Scott
Teflon plumbing tape, or a tight fitting O-ring underneath the spring
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Old 09-01-2011, 08:10 PM
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Quote:
And yes it's not a true boxer engine.. Both cylinders hit tdc at the same time
I thought that was how all the rc 2 cylinder opposed engines ran? Which ones dont?
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Old 09-01-2011, 08:22 PM
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I thought that was how all the rc 2 cylinder opposed engines ran? Which ones dont?
It may be?? I dunno?? But a true boxer fires one after the other. So a true boxer 2S is always on a power stroke..
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Old 09-03-2011, 05:53 AM
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That is in four stroke opposed twin (boxer) engines. Two stroke opposed twin fire simultaneously.
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Old 09-03-2011, 08:04 PM
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It must be just model engines. I took it to the local small engines tune / repair joint and he said it's weird.. He has only ever seen 2stroke engines fire opposite each other..

I have my new plugs.. Let's go tear my arm out again for 3 hours flicking it.. The gaps are alot finer on the ngk's.. 16 thou gap.. Fingers crossed..
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Old 09-04-2011, 03:50 PM
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With a new CDI?
If the working cylinder follows the switch of caps, something is wrong there isn't it?
Even then, if tuned properly, the engine should run on one cylinder only.
How good is the guy at your local repair joint. Do you trust him? I would not if he does not know about boxer two strokes.
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