Author Topic: valves (Read 2670 times)

Dragon888 · « **on:** April 27, 2007, 02:57:37 AM »

Is it true that one cause of loose compression are leaking valves? If so how can we fix that? Just cant get my bike to start. The mechanic told me that my bike has leaking valves thats why I cant start it and the bike also has very rich fuel mix no matter what adjustments were made. Sill its very rich burning bike and fouls the plugs easily with carbon. Help pls.

BrianM · « **Reply #1 on:** April 27, 2007, 11:23:47 AM »

If the mechanic didn't do a leakdown test, he's just trying to blow smoke up your butt. But the only way to fix those is to remove the head and have the valves replaced (if they're burnt/damaged) and everything reseated. Lots of work, and thus money, so make damn sure it's necessary... a leakdown test is the best way.

The carbs running rich is Super common, you need to replace all the rubber bits in the float bowls of the carbs (2 o-rings and 1 rubber plug per carb, and possibly the float needle/seat too). when that stuff is rotten/not sealing, you get a REALLY rich running bike, to the point where it probably won't start/run.

gsxr400 racer · « **Reply #2 on:** April 27, 2007, 11:54:53 AM »

and the emulsion tubes (needle jet)

turbofb · « **Reply #3 on:** April 28, 2007, 03:51:33 AM »

He might have meant that the valves are hanging open due to tight valve clearances.....which is pretty common on our high revving little engines.If you dont do valve adjustments regularly,then youll end up with "leaking" or worse,burnt valves.Before you tear the engine apart,pop the valve cover and check your clearances......