LaVern Posted April 2, 2023 Report Share Posted April 2, 2023 I have a1975 RL250 I reconditioned several years ago. In the process I needed a new petcock due to leaking past the on/off position, plus leaking around the petcock on/off lever. I originally found a supposed OEM petcock from Partzilla I believe it was, and it worked but the location where the gas line connected sat lower than the original and since it exited out the back the line hits the throttle cable on the carb so a pretty extreme angle on the gas line is needed, so much so that it partially kinks the gas line. Since it is threaded, and the body of the petcock can be rotated, I had just turned it to miss the throttle cable. The trouble with that is it puts the lever facing forward making access somewhat difficult. So last year I got another petcock from Steven Pitt at Suzuki/Beamish Owners Club who I think has sold it to someone else now but that really doesn't matter. He said many people had used that petcock very successfully so I bought that. Well it is Identical to the OEM one I got previously. As I said, it will work but not as nice as I would like, and it is definitely different than the original that came on the bike. I am the original and only owner and have never had it replaced until several years ago. Any way that was along way to get to this point. Does anybody know the thread size on a 1975 RL250? A petcock that would have the line exiting to the rear, towards the rear tire, instead of towards the carb would be perfect. I see quite a few on line that look to have the same method of threading on the tank. I just need to know the thread size to be sure they are the same. I am unfamiliar with metric pipe threads, and I have tried to match up a metric bolt thread with no luck. Thanks for reading and any information is greatly appreciated. I probably should have taken a picture of the original vs. the newly purchased one for comparison. I will try to get to it tomorrow. LaVern Quote Link to comment Share on other sites More sharing options...
b40rt Posted April 3, 2023 Report Share Posted April 3, 2023 Try again with plumbing type fibre washer ? Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 3, 2023 Author Report Share Posted April 3, 2023 b40rt, The leakage from the original petcock was out from the face of the petcock plus it is unable to shut off fuel to carb completely. No problem with fitting up to the tank itself. This has to do with the rubber disc that controls the off/on/ reserve positions of the petcock. The rubber washers on the new petcocks are not interchangeable. I may end up just using the new petcocks but I am hoping to get a petcock that allows the lever to face outward. Thus thread size needed. Thanks for your response. LaVern 1 Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 3, 2023 Author Report Share Posted April 3, 2023 (edited) I'm going to try to download the pictures comparing the new vs. the OEM. The new is on the left and the OEM is on the right. This is looking at them from the backside. As you can hopefully see the outlet on the new one is lower than the OEM, and this is just enough to hit on the cable coming out of the carb top. That's why if a petcock had the exit to the right or the rear towards the rear wheel it would clear everything. I may have to further research metric threads. LaVern Edited April 3, 2023 by LaVern better explanation. Quote Link to comment Share on other sites More sharing options...
lsv Posted April 4, 2023 Report Share Posted April 4, 2023 Could use a honda tap - probably same thread. Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 4, 2023 Author Report Share Posted April 4, 2023 1 hour ago, lsv said: Could use a honda tap - probably same thread. That looks like what I am looking for. Do you know specific model and year? LaVern Quote Link to comment Share on other sites More sharing options...
lsv Posted April 4, 2023 Report Share Posted April 4, 2023 I suggest you check thread dia to see if it is 14 or 16mm then just do a search on evilbay for Honda petrol tap (loads on there) find the one that is right size etc see what model(s) it fits and buy a genuine Honda one rather than the chinese **** that proliferates on there! 🙂 Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 4, 2023 Author Report Share Posted April 4, 2023 That sounds like a real good idea. Thanks for that. I take it the metric 14mm or 16mm are the standard pipe tread sizes ? I have checked metric bolt sizes and found nothing to fit. I'll do what you suggest and post back on here my results. Thanks. LaVern Quote Link to comment Share on other sites More sharing options...
b40rt Posted April 5, 2023 Report Share Posted April 5, 2023 On 4/3/2023 at 12:00 PM, LaVern said: b40rt, The leakage from the original petcock was out from the face of the petcock plus it is unable to shut off fuel to carb completely. No problem with fitting up to the tank itself. This has to do with the rubber disc that controls the off/on/ reserve positions of the petcock. The rubber washers on the new petcocks are not interchangeable. I may end up just using the new petcocks but I am hoping to get a petcock that allows the lever to face outward. Thus thread size needed. Thanks for your response. LaVern I was thinking the fibre washer would change the position of the tap when tightened ? Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 5, 2023 Author Report Share Posted April 5, 2023 That another good thing to look at. Thanks. LaVern Quote Link to comment Share on other sites More sharing options...
lsv Posted April 6, 2023 Report Share Posted April 6, 2023 (edited) On 4/5/2023 at 12:28 AM, LaVern said: I take it the metric 14mm or 16mm are the standard pipe tread sizes ? Usually 1.5mm pitch for both. Check yours with pitch gauge to be sure. (or use a standard M10 bolt to check against as they are 1.5mm pitch) Edited April 7, 2023 by lsv more info Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 16, 2023 Author Report Share Posted April 16, 2023 Well it has been a few days since my last post. I have found a petcock that works and it is exactly the setup I was looking for. After an extensive search I came upon the website Dime City Cycles. After a couple of emails, Sam at customer support said they had a petcock and it was the correct thread, 14mm x1.5. When it arrived I thought I hit another brick wall. The thread was not 1.5, but something finer, perhaps 1.25 or even 1.0. Fortunately I was able to remove the threaded collar from the new petcock and replace it with the original collar. The thread on the petcock body was the same as the original, and I was able to use the original Suzuki collar. I am having trouble resizing the second picture I have with gas line installed. I may try later, but here is the installed picture and we rode it yesterday without any leakage. I am satisfied with the results. Lavern 1 Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 16, 2023 Author Report Share Posted April 16, 2023 Finally I got it small enough 1 Quote Link to comment Share on other sites More sharing options...
LaVern Posted April 16, 2023 Author Report Share Posted April 16, 2023 (edited) FYI the SKU# for this petcock is SKU: KL18-4170. When I ordered mine it was the last one they had, and after just checking the SKU on their site it shows no results. I don't know if they'll be getting any more in stock. I see that Dark Horse Motorcycle parts has it listed as a FUEL PETCOCK - YAMAHA DT100 77–83 . Maybe Partzilla or other OEM suppliers may have this. LaVern Edited April 16, 2023 by LaVern Added information Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.