ejc34710

Having an issue with my LRP 28 spec 3. It is installed in my Savage X. After a recent run, it wouldnt start back up. Fuel would not make its way up the line and to the carb when priming. It would shoot right back down the line and into the tank after i primed it. Poured a little fuel into the carb, and it sizzles real bad, like th engine is too hot. It dosent run like its lean, and im getting temps of only 225-230 (verified by 2 different guns). Never did this before, and have never run into this problem on any other nitro i've had over the years. Thoughts?

nitroexpress

Vapour lock. Carb is overheated.

ejc34710

How in the world can the carb get overheated when the plug is only at 230ish? Never had this problem before too, weird. I thought vapor lock meant the engine was flooded...? Pulls just fine, am i missing something.

nitroexpress

Newest design of carbs are phenolic and/or have heat isolating collars on their throat. Engine might be running at a good temp, but vapour lock can occur when the carb body is a similar temp. Vapour lock doesn't mean the engine is flooded, it means the fuel is boiling and vapour (pressure) is preventing the flow of fuel. The cure - anything that cools the carb body. More holes in the body, running richer. Carb could be replaced with a more heat resistant design.After running, you could spray the carb body with a freeze spray from Radio Shack or motor spray to cool it down. If this works (and it should) then your problem is definitely vapour lock.

ejc34710

You desribed the problem perfect. Weird, must have just been running it a little more lean than normal. Thanks for the info, much appreciated. I'll figure something out. Wish these darn LRPs didnt load up so much on the low end... Thanx again.