major problems

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tacky1
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Location: Pacifica,,

Re: major problems

#31 Post by tacky1 » Fri Apr 14, 2017 2:21 pm

Juicebox wrote:I get it...my post is long and unreadable. I will figure things out on my own.
Great, now throw in attitude,
How has figuring it out on your own worked out!!!!

4 engines destroyed.. That is just unreal!!! 4......
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

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Juicebox
Posts: 450
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Location: sconsin

Re: major problems

#32 Post by Juicebox » Fri Apr 14, 2017 8:35 pm

I now realize that my last post sounded pissy, but I wasn't trying to be. This forum has always helped me out, and I am appreciative. Just didn't want to answer your questions with more rambling answers that confuse instead of enlighten. I also have 3 small children that make it hard to do things quickly. I would read your replies, and then get distracted, and then forget to answer your questions or even what you guys said. Just figured I would take it slow and keep reading to try and figure it out.

Jon, There was no leak down test on this latest motor, or any of them. I've read about leak tests, but never done one. Can it be done with the engine in the bike? Reeds on or off? If a leak down test is done and it shows that there is a leak, is there a way to determine exactly where the leak is?

There have also been no changes to the jetting for any of these engines. I think that may be one of my issues. It currently has 20 pilots 1 1/2 turns out, dynojet needle three grooves from the top and 420 mains. What do you guys think about me enriching every circuit and working my way down? Not really sure how to do plug chops at full and 3/4 throttle, and also pamper the engine during break in.

I will go back and reread all of your replies to ensure I understand what is being said and also to make sure I answer your questions.

Lastly, when I am trying to learn something new and really understand it, my mind is all over the place trying to figure things out. It is hard for me to think in a deliberate, logical manner because I dont even know where to start. My thoughts aren't linear, they are like a ball of rubber bands....no beginning or end, just confusion. That's why I tend to ramble on. Thanks again to all.

P.S.
Tacky, I have only blown up 3 engines. And my brother blew up one of those, and I fixed it, so i'm not counting that. :smt001

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JonW
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Re: major problems

#33 Post by JonW » Sat Apr 15, 2017 3:53 am

Juicebox wrote: Jon, There was no leak down test on this latest motor, or any of them. I've read about leak tests, but never done one. Can it be done with the engine in the bike? Reeds on or off? If a leak down test is done and it shows that there is a leak, is there a way to determine exactly where the leak is?
Yes can be done with the engine in the bike. pull the carbs and pipes, the rest stays on.
you spray on soapy water (if you search on here people have found other potions that work well too) and see if you can see bubbled. Obviously if you cant find it outside, its inside and you need to pull teh flywheel and the clutch cover and see whats going on in there.

This will help perhaps:
viewtopic.php?f=21&t=14615" onclick="window.open(this.href);return false;
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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JonW
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Re: major problems

#34 Post by JonW » Sat Apr 15, 2017 3:56 am

I'll start a new post so this doesnt get lost.

When youve built and tested the new motor we will talk about jetting.

One step at a time.

You first need to prove its not sucking air in and that the oil system is working (or use premix).

Building engines is iterative, a set of processes that you follow.

With new bores, new crank (not some shit used thing) and decent pistons lets slowly work up to getting you a running motor, not just bang stuff together with old parts and guesswork.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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Juicebox
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Location: sconsin

Re: major problems

#35 Post by Juicebox » Sat Apr 15, 2017 8:06 pm

Got it. I will do leak test before anything else. I also took the flywheel off to make sure the guy who put this engine together didn't put the timing advance back in. He unknowingly had. It is back to stock now. Thanks to all.

ief
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Re: major problems

#36 Post by ief » Sat Apr 15, 2017 10:15 pm

May I offer a fresh look.

One thing in common will be the fuel tank with a petcock that can fail and a gascap/ tank breather that can fail as well.

Cheers.
O no, red pilled.

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Juicebox
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Re: major problems

#37 Post by Juicebox » Mon Apr 17, 2017 2:59 am

Its interesting you should say that. After the brief maiden ride with this last engine, when I told the builder there were still problems....I said it was acting as though it was starving for fuel. He then took it around the block and said a cylinder was cutting in and out. He said he thought it was electrical and I quickly forgot about my first instinct.

A leak tester is on its way, but I was wondering what I can do to check this fuel theory while I wait for it?

RuZty
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Re: major problems

#38 Post by RuZty » Mon Apr 17, 2017 5:05 am

Once you have started the engine set the petcock to prime to rule out the vacuum function. Go for a ride, and when it starts acting up crack the gas cap open (best done with less than half a tank, and avoid heavy braking). You might need to leave a spare key in the cap for this. If it goes back to normal you have your answer. Don't forget to take it off prime when you get home.

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Juicebox
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Re: major problems

#39 Post by Juicebox » Tue May 16, 2017 12:14 am

Ok. I know its been a month, but like I said, with 3 small children its hard to find time. I did a leak test today and it passed the test. I pressurized to 7.5 pounds and it was above 7 pounds five minutes later. I also did some other things today, and thats where my new questions come from. Since I had things opened up a little, I thought I would test my coil. I looked in the service manual, and read the spark gap test procedure. I dont have an electro-tester, and I didn't understand anything anyways, so I didn't really do anything. A mechanic friend wanted to do something though, so he got out a power probe, disconnected the plug from the coil to the harness, connected his power probe to my brand new ballistic battery and stuck the probes into the plug coming from the coil. Nothing seemed to be happening, but two minutes later, my new battery was dead. This battery is brand new, and hasnt even been on a running bike ever. This is the second ballistic battery that has died in this bike. Could any of these electrical issues be causing my engines to blow up, or did my friend just fuck something up? Anyways, thats where im at. The bike hasnt run or moved in a month, but the pressure is good and my battery is dead. Thanks for any more advice.

waltmil
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Re: major problems

#40 Post by waltmil » Tue May 16, 2017 6:43 am

Not sure what you expected to happen. The primary coil resistance is low so it sounds like you shorted the battery through it. These bikes will run with a dead battery. It is very unlikely the battery is the source of your problems.
Red/White US '84, Spec II pipes, Y-boot w/K&N, Fox Shock, Mikuni carbs?

Palolo
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Re: major problems

#41 Post by Palolo » Tue May 16, 2017 5:08 pm

Juicebox my 2 cents, sell this bike, buy another RZ350 that's running well and don't mess with it. Let the owner ride it around at high rpm's and prove to you that the bike is properly tuned.

I'm scared to think about how much money you've spent on this.

RuZty
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Re: major problems

#42 Post by RuZty » Wed May 17, 2017 9:06 am

As Walt said, if your buddy shorted the battery across the primary coil that would kill the battery pretty quick. While the bike will run with a dead battery I don't think you want to proceed with a known handicap based on past history. I have never had an RZ coil fail but they are more likely to quit completely than intermittently. Compare your coil to the one on your brothers bike, since that bike works it should be your reference. Good job on the pressure test, go back and follow up on some of the other questions and advice.
Here is good troubleshooting chart for electrical problems, save a copy to your computer.

http://www.electrosport.com/media/pdf/f ... iagram.pdf" onclick="window.open(this.href);return false;

It is generic, but leads you through the process in a structured manner and will help you isolate a problem.

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