aftermarket petcock / fuel shutoff valve

Mike (MA) /

Petcocks can be hard to come by, leak often, and are just finicky parts. www.denniskirk.com is an aftermarket snowmobile/motorcycle store. They've got a brass in-line fuel shutoff valve (use w/ 3/16 fuel line) for $9.99 that looks like a cheap and sturdy solution, if coupled w/ an in-line fuel filter. Can anyone think of any real problems w/ using one of these?

http://www.denniskirk.com/asp/detail.asp?PartNo=511592&ProdType=10&SubProdType=fuelline&Name=Search&MultiDim=N

(if this link doesn't work, search for petcock under street bikes).

-Mike

Re: aftermarket petcock / fuel shutoff valve

Ron Brown /

Mike,

I used these petcocks on my 2 Motobecane Model 7's.

I found a brass fitting at a hardware store with the same thread on one end as the thread in the tank. I silver soldered a brass washer to the base of the thread so that when I screwed it into the tank, I could use a nylon washer to seal it. I cut the other end off the fitting, filed it flat, then tapped it internally. I cut the same thread on one end of the petcock and screwed it into the brass fitting with a nylon washer. You can add and remove washers to get the lever to line up when it is tight.

I have no reserve of course, but have had no problems with these petcocks.

Ron

lawnmower store.... $4

Your local lawnmower store sells inline plastic on/off valves with O-rings.

Not a bad deal at all.

back yard $.04

skatecheap /

clothes pin - 4cents :{)

pedal yer ass on a bicycle ... FREE

dumbass

FREE, hee,hee

skatecheap /

if it's a penny for your thoughts.....

how come it costs 2 cents.. to put your 2 cents in?

SOMEBODY IS MAKING A PENNY!

Re: aftermarket petcock / fuel shutoff valve

Well,Mike,no problem if you're as savvy as Fred,Ron,or a lot of experienced mopeders that realize it's all about keeping dirt from the tank out of the carb.You can use what they say if you realize you'll have to add an extra filter,`cause just any valve won't have a filter sock on it.I really like a see-thru paper filter from Auto-Zone to intercept any dirt or debris before the carb screen.There isn't much can get thru that paper,and they're throw away filters,so you can put on a new one every year for 3 bucks.

Re: aftermarket petcock / fuel shutoff valve

Mike (MA) /

> > Did you have problems finding a fitting that had the same threads as

> > your gastank? I have a Puch, so I'm assuming those threads are metric,

> > and I'm having a hard time finding any metric plumbing fittings that

> > match it.

Re: aftermarket petcock / fuel shutoff valve

Ron Brown /

Mike,

Now that I have hrassed you into posting this on the forum instead of emailing me directly, I am not sure I can answer your question directly.

I am the proud owner of two tap and die sets, one sae and one metric. The kind that costs about $12.00 So I may have re-cut the thread on the brass fitting that screwed into the tank but I do not recall having to do that. The Motobecane gas tank has a square nut on the inside of the tank, held in place by metal tabs, the petcock screws into this nut and a washer between the petcock and the outside of the tank seals it, so I can't measure the thread without draining the tank and un-screwing the petcock.

My best recollection is that the nut had a standard thread which either matched, or was very close to, the thread on the brass fitting I used. I may, or may not have run a die down the brass fitting to make it fit but I just can't remember. I am sure that I had no real trouble maked it fit.

I hope this helps.

Ron

Re: aftermarket petcock / fuel shutoff valve

First off . Ron You must love tinkering . ( not a bad thing at all ) but you seem to have gone to an awful lot of trouble and expense to save yourself about $15.00. Also the tread size on your mod 7 is 10 mm X 1.

Second Mike.

While you are correct that making a petcock will undoubtedly be better than the cheap aftermarket ones I have seen. Your best bet may be to buy an original Puch Valve. I have the entire inventory of Original Puch valves For all Maxi, Magnums, and Cobra models. I also have some of the aftermarket ones that I use for paper wieghts.

Chris

Tinkerers R' us

Ron Brown /

Chris,

You are right of course, Mike should buy an oem as long as they are available, but in my own defense, my 2 Motobecane model 7,s were given to me including the brass adaptors and a gas (natural) valve assembly which was way too big and heavy to fit and I had one of the small brass in-line valves that I used on a remote gas bottle for tuning. Having these pieces in hand, it only took about 15 minutes to cobble a pet cock that looks and works well and can be replaced at the local motorcycle shop, if needed.

I am guessing that the brass adaptors were a pipe thread which approximated the metric thread in the tank closely enough to screw into the captive nut without binding.

Did I mention that I cut down an aluminum bicycle pump to fit the frame pegs like the original. Oh... the chrome plastic door protectors at the auto parts store are an exact replacement for the chrome trim on the frame down tube. I almost forgot, I also sized my own main jets using a clock bushing tool to reduce the size and a Honda condensor wired into the harness at the coil to replace the bad oem on one of them.

After 2, 200 mile round trips to moped army BBQ,s, the bicycle pump worked perfectly for roadside tire repair and the petcocks work perfectly.

I don't have an in line gas filter, I acid cleaned the tanks and rely on the screen in the carb to keep the big stuff out.

By the way, which shop are you now working for?

Still tinkering.

Ron

Re: Tinkerers R' us

Way to go Ron! Or should I say McGuyver? On the condenser note The major cause fo motobecane condenser failure is actually rust in the tank. It causes the engine to run at an ellevated temperature and the condenser begins to absorb heat rather than disapate it. The plastic rectangular Novi condenser (or your method) is the answer.

I own the Moped Warehouse in New Jersey.

Chris

Re: Tinkerers R' us

Ron Brown /

Chris,

It all comes back to me now! I think you are the guy who I gave the Kudos to on this site, for your assistance, when I was trying to solve the condensor problem so that I could go to the BBQ.

As I recall, you used to post with an ISP that indicated you worked at a moped shop. I realise this forum is not for advertising, but considering the excellent advice you dispense on the forum, I am sure no one would mind if you added (Moped Warehouse) after your name.

I also like your theory on gas tank rust causing condensor failures. This is so obscure, you have to love it. I have to pass on this being my problem, however, as the ped only had about 100 miles on it and they were from it's younger days. I believe my condensor died of old age, most likely from moisture getting past the seal. I still think that this is a dumb place to put the condensor anyway as it is prone to collecting mass quantities of crud which must affect heat dissipation.

Ron

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