English French German Italian Portuguese Spanish Swedish

rotax brp

 

503 single carb egt spread

  • david dixon
  • david dixon's Avatar Topic Author
  • Offline
  • Fresh Boarder
  • Fresh Boarder
More
2 years 6 months ago #10680 by david dixon
david dixon created the topic: 503 single carb egt spread
I have a 503 sc di with 8 hrs after rebuild. The front cly ( mag end)is showing signs of high temp (red/orange plugs). The back looks ok. I just bought this engine trike combo and havent had a chance to put an EIS on it yet. It has analog gauges and they're all over the place. My EIS is on its way so I'll have good reads to go by then. What can I look for other than air leaks around the carb and intake? Thanks in advance

Please Log in or Create an account to join the conversation.

More
2 years 6 months ago #10683 by Nick Axworthy
Nick Axworthy replied the topic: 503 single carb egt spread
Before I converted my 503 to duel carbs...one of my cylinders alway had a lighter burning plug.

Tried angling the carb in different directions...did not help...I just put up with it...assuming it was down to airflow and something I could not alter.

With my DC set-up both plugs are exactly the same colour...glad I went to the trouble to convert smoother running ect ect...and glad to get way from those delicate SC inlet manifolds.

Nick.

Please Log in or Create an account to join the conversation.

  • david dixon
  • david dixon's Avatar Topic Author
  • Offline
  • Fresh Boarder
  • Fresh Boarder
More
2 years 6 months ago #10689 by david dixon
david dixon replied the topic: 503 single carb egt spread
Thanks. I plan to jet it a little fatter to be on the safe side. What is the hp gain you get from 2 carbs?

Please Log in or Create an account to join the conversation.

More
2 years 6 months ago #10692 by Nick Axworthy
Nick Axworthy replied the topic: 503 single carb egt spread
Any air leaks would tend to effect both pots as its a common inlet manifold...saying that...the the Sc manifold is prone to getting cracked if the jugs are not lined up correctly...worth checking for a crack on one end.

I think the book says you get another 4 to 6 HP...

Red orange dont sound to bad...its when the go whitish you need to worry.

Please Log in or Create an account to join the conversation.