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Hello I'm new here .. Hoping to get an answer.

J

Jclemo

New Member
Hope I'm posting in the right place..
Recently replaced 883 pistons and jugs
With 1200 pistons and jugs used the 883
Heads. I noticed I feel air coming out of the rear cylinder around the rocker box area. There are no oil leaks anywhere. Anyone know why or how this could be happening my spark plug is tight. I also noticed the rear cylinder pipe gets hotter than the front pipe. 1 3/4 drag pipes.
Thanks. J Clemo
 
Welcome to HDT from sunny AZ.
Have you tried a leak down test to see if your losing compression?
 
Welcome
May be lean for the heat.
Use small spray shots of carb cleaner around the intake manifold if it changes the idle you have a leak.
Bring the piston to top dead center with the plugs out than with a rubber tip blow gun pressurize the cylinder with some air, 10 lbs or so.
You can wet the palm of your hand and cup it around the head gasket area or spray soapy water along the gaskets.
Also see what amount of air come out of the oil fill hole.
 
Jeff Klarich said:
Welcome to HDT from sunny AZ.
Have you tried a leak down test to see if your losing compression?
Click to expand...
Actually it is the spark plug. The threads are shot. Not to point it won't hold the plug but bad enough the air leaks by. Recently installed 1200 pistons and jugs and used the 883 heads. It's got plenty of compression. But my other head had bad threads as well so I bought a used head on eBay and didn't install the head untill a month later. Plug fit in the hole kinda loose but tightened up ok. So after a week of running with a kind of miss fire at idle I found this air coming out around the rocker box I thought but turns out another bad plug hole. Two heads same problem. What to do? Any ideas? Thanks. JC
 
As per Jeff's post will work.
Be sure the piston is down.
Follow the use of grease to catch the shavings and use a vacuum with a small hose tapped to it to clean the inside of the cylinder, follow up with a small grease covered piece of a rag tapped on a wire so you can go into cylinder to try to wipe to top of the piston.
Blowing air into the cylinder may lodge chips between the cylinder wall and piston.
 
I would use a helicoil or recoil kit to replace the threads when i have done this in the past i have always removed the head and done the work on the bench
some red loctite on the coil kit can help stop it from moving

Brian
 
Good advice from fin_676. Don't take a chance on missing a bit of metal in the cylinder; bad juju can only follow. More work but at the end of the day, no worries.;)
 
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