Right Head Hot/Left Head Cold (Moved to Wrenchin’)

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ekiss2010
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Right Head Hot/Left Head Cold (Moved to Wrenchin’)

Post by ekiss2010 » Sat Mar 30, 2019 8:39 pm

Ural Gods,

I have an issue with my Dnepr. As you know I recently purchased an MT16 and got it running this morning. After a quick degrease and spray of the hose, I noticed that the right head is running extremely hot and the left head is very cold (i.e. I can touch the left head after idling for a minute but I will burn myself on the right head). I pulled the plugs and both are black. The plugs are brand new. I am not sure if there is an issue with the spark plug wires or what. Any suggestions will help.
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Re: Right Head Hot/Left Head Cold

Post by jeffsaline » Sat Mar 30, 2019 9:14 pm

No personal experience with your machine but can you swap sparkplug leads and see if the issue follows the leads? If it does it suggests something with the ignition. If it doesn't it is probably something with the fuel system or maybe valve adjustment(compression) or exhaust.

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Jeff
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Re: Right Head Hot/Left Head Cold

Post by biker » Sun Mar 31, 2019 12:37 am

Don't think swapping plugs is the answer and sounds more a fuel mixture or idle adjustment. The center of the plugs shouldn't be black but a light coffee brown. Start it up and let it warm up and then pull the plug wire on one side, place it back on and then do the same with the other. On either side they should sound like there running at the same low RPM.
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Re: Right Head Hot/Left Head Cold

Post by RC20 » Mon Apr 01, 2019 7:30 pm

Cooler or just Cold?

You clearly have an carbuaration problem.

That is serious hot with the black so you don't want to run it on the road at all and as little as possible while sorting it.
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Re: Right Head Hot/Left Head Cold

Post by ReCycled » Mon Apr 01, 2019 8:16 pm

We're going to need some more info but looking at the photos, I I'm worried you don't know your left from your right :)

Can you give us comparison numbers for temperatures? If you use an infrared thermometer be sure to sample similar location in both cylinders... Or just drop two meat thermometers down through the holes in the heads near the sparkplugs.

What carbs are you running? How are you synchronizing them?
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Re: Right Head Hot/Left Head Cold

Post by RC20 » Tue Apr 02, 2019 10:40 am

Also best put in the Wrenches.
Fear No Gravel
Formerly Owned: ( various rides on others)
Honda 90
2 x CB750K (one a true Japan Model flown to Hawaii by a P3 Orion Sub Patrol Aircraft!)
1 x CB700 SC ala Shaft Drive Nighthawk S (RC20 is the actual in house production Model)
1 x R80GS (ok to start with, learned to love it for what it was)
1 x CB450K

Current:
1 x 2019 cT Terracotta

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Re: Right Head Hot/Left Head Cold (Moved to Wrenchin’)

Post by darkhorse » Wed Jun 12, 2019 10:30 pm

I had a problem where one side was running hotter than the other. It boiled down to a fuel delivery problem on one side.

The spark plugs look equally fouled. Likely cause is too much fuel in the cylinder or not enough air. Easy things could be running it with the choke on/stuck choke or a clogged air filter. Worse things could be oil getting up into the combustion chamber.

You did not provide much detail on how you found the problem or how the engine starts and runs. More detail will help the folks on the forum give you better direction.
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