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Intro and rusted on riser question

Mxzx

Mxzx

Contributing Member
Hello all! Been lurking on here for a while and figured it was time to join and ask a few questions!

We have a '89 Tiara 2700 Open with FWC, and all original exhaust components! Finally starting to get reduced water flow at exhaust on one engine. Figure it is time for an elbow/riser change.

Our question is what is the best way to break riser loose from manifold? Read one post where a sledge did it, is there a better way?

Would appreciate any other insight you might have.

Thanks!
 
Heat is often our friend. Penetrating oils can take weeks to get into where they need to be..... if you are even that lucky.

Warm the engine up to operating temperature.
Crack the bolts loose, and try to break the elbow/riser loose from the manifold.
DO NOT hammer on these cast iron components! :mad: Especially if you believe that they can be cleaned up, saved, and re-used.
If you are sucessful, you can complete the work after things cool back down.


If need be, pick up a pair of knife-edge faced steel fox wedges.
7FWSS10025_ICON.JPG

These can be gently forced in between the two mating surfaces.
If you scare the faces a bit......, these can be re-dressed on a Machine Shop Surface Sanding machine.
It won't be a deal breaker if you were to scare these. You may need to re-surface these anyway to end up with nice clean and crisp sea water transfer ports.

I'd ask what their hourly rate is and I'd arrange for this ahead of time.
I'd also stay there while they do it so that you're charged for only the time required.
Takes a good machinist about 5-10 minutes for each surface..... if that!





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Original 1989 risers!!??

I wouldn't worry about salvaging any of those....a better way; yes, a rosebud on the end of a torch...provided you have enough room to make use of it.
 
Update:

After splitting the elbows and risers, the passages had some rust in them, but mostly at the joint between two. After chipping and scraping away, managed to get them to flow much better. Never got the risers off the manifolds, but the engine now stays at 150-160.

Will probably order new ones at some point, but at least boat is back in action now.
 
What engines?

Are you located in fresh water or salt?

Risers (extensions) and elbows can last almost forever in fresh water. 5-7 year maximum in salt.

Gene
 
It's in Southwest Florida, run in Gulf.

They are 350/270 hp's.

The boat is only used about 4 weeks a year, sits on lift rest of time.

We do flush it after using before long term storage.
 
Yikes, our '87 Tolly 34 has had 5 new sets of risers since new. I change 'em every 5 years.

You may get a few more years out of a set if you flush after each use and dry store the boat. But 23 years on a set of risers in salt water is scary. As much as reduced water flow is an issue, the real problem would be rust through that allows salt water into your engine. Catastrophe!!
 
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