- Joined
- Dec 28, 2008
- Messages
- 2,035
When I went through my Mk III one of the "systems" I replaced was fuel delivery. I replaced the petcocks, the fuel line and the carburetors, I douched the tank; everything was sub-surgically clean and free of crap. For the first 250 miles all is well; as I begin to raise the throttle for slightly extended periods I find I'm swtiching to reserve. The first time it did this I headed to a gas station and found plenty of fuel in the tank, so I'm thinking that, maybe, I didn't do quite as good a job of cleaning the tank as I thought.
So, fine, I'll keep the tank full, keep both petcocks open and blow everything out at the 500 mile mark, but not wanting to be left without options I call Rabers and purchased a pair of Paioli petcocks, just in case...
Two days ago I start in on the 500 (early---I hate off spec performance), I drained the tank, looking for debris, but nothing. I removed the petcocks and did a visual, the main tap had a passage that was bearly .030 in diameter, bearly larger than the main jets! I stripped it and found that the hole drilled in the brass barrel was significanly offset to the main bore of the valve, causing the restriction. The reserve was properly bored, but had a great intrusion of the neoprene/butadiene sealing material, some of which I found in the screens just south of the carbs.
Needless to say I installed the Paioli's that have "guts" similar to the non-vacuum Japanese types.
Today, after a good warm up--beautiful day in New England-- I headed out to the interstate and found that crusing at 80 MPH (long enough to see a major difference--not long enough to hurt a new engine), on the main tap, produced no symptoms of fuel starvation.
Anover Norton petcock users beware of false fuel starvation issues
RS
So, fine, I'll keep the tank full, keep both petcocks open and blow everything out at the 500 mile mark, but not wanting to be left without options I call Rabers and purchased a pair of Paioli petcocks, just in case...
Two days ago I start in on the 500 (early---I hate off spec performance), I drained the tank, looking for debris, but nothing. I removed the petcocks and did a visual, the main tap had a passage that was bearly .030 in diameter, bearly larger than the main jets! I stripped it and found that the hole drilled in the brass barrel was significanly offset to the main bore of the valve, causing the restriction. The reserve was properly bored, but had a great intrusion of the neoprene/butadiene sealing material, some of which I found in the screens just south of the carbs.
Needless to say I installed the Paioli's that have "guts" similar to the non-vacuum Japanese types.
Today, after a good warm up--beautiful day in New England-- I headed out to the interstate and found that crusing at 80 MPH (long enough to see a major difference--not long enough to hurt a new engine), on the main tap, produced no symptoms of fuel starvation.
Anover Norton petcock users beware of false fuel starvation issues
RS