Does anyone know what size wrench to use for the lower, larger bolt on the flange that the riser is attached to? I can't get a socket on there without it slipping due to the elbow. The socket is at too much of an angle on this rusted stud and bolt. Is it safe to use a torch on this?
Removing M25-XP Exhaust Riser
- Thread starter Project_Mayhem
- Start date
Same size as the other nuts on those studs.
Here's a tip:
Muffler & Exhaust Riser Replacement 101 (2015 Tech Note with Tips & Tricks)
Muffler & Exhaust Riser Replacement – 2015 – Catalina 34 International Association
EDIT: see text in reply #4 below
Here's a tip:
Muffler & Exhaust Riser Replacement 101 (2015 Tech Note with Tips & Tricks)
Muffler & Exhaust Riser Replacement – 2015 – Catalina 34 International Association
EDIT: see text in reply #4 below
Last edited:
My apologies for posting that protected link. Here's the operative text:
Exhaust Riser Removal Tips & Tricks: The hardest thing to do is get that bottom nut off the stud (even after soaking with PBBlaster; carefully mask the transmission to avoid any PBB getting on the seals). We had gone through this “bottom nut” difficulty in 2003 and again in 2008. I had given it a lot of thought and came up with this: While Morgan held a 9/16″ box end wrench on the nut from below, I took a huge long one inch combo box/open end wrench from above and he held the open jaw of it on the end of the lower wrench while I hit it with a big hammer. Bingo! The nut came right off. Instead of trying to work that nut off from below, use two people and as much leverage as you can manage to work it off. Sockets and ratchets won’t work on that nut because of the configuration of the exhaust riser and the connection to the manifold. That long wrench & hammer worked, right away. Tightening the bottom nut back onto the stud: We simply reversed the big combo open/box wrench trick, making it very easy to get it tight.
Exhaust Riser Removal Tips & Tricks: The hardest thing to do is get that bottom nut off the stud (even after soaking with PBBlaster; carefully mask the transmission to avoid any PBB getting on the seals). We had gone through this “bottom nut” difficulty in 2003 and again in 2008. I had given it a lot of thought and came up with this: While Morgan held a 9/16″ box end wrench on the nut from below, I took a huge long one inch combo box/open end wrench from above and he held the open jaw of it on the end of the lower wrench while I hit it with a big hammer. Bingo! The nut came right off. Instead of trying to work that nut off from below, use two people and as much leverage as you can manage to work it off. Sockets and ratchets won’t work on that nut because of the configuration of the exhaust riser and the connection to the manifold. That long wrench & hammer worked, right away. Tightening the bottom nut back onto the stud: We simply reversed the big combo open/box wrench trick, making it very easy to get it tight.
Thanks
Thanks for the info. I found that link in another post and was thinking about PMing you when I saw that you wrote the article. The nut on the bottom is definitely bigger on my motor. The top two studs are fine thread. I'm not sure if the bottom one is as well since there's a fair amount of rust. I have a M25-XPAC that was built in '93
Perfect! Thank you!