Volvo penta 4.3GL PWTR running great and cool except for right side exhaust down pipe

[mr_carman007]

Alright so, I have come a long way on this boat. I have removed exhaust manifolds and risers, cleaned them out very well, took the raw intake system apart to replace the thermostat and impeller, cleaned all kinds of impeller pieces out (pretty sure I got them all), and reassembled. I started it up on the nose today and it ran awesome, nothing on the motor overheating! I thought I did an awesome job until I hit the exhaust down pipe (not the exhaust manifold) with my thermometer... It was almost 220 while the other side was only 120-130. Anyone else experienced this? Did I not get all the impeller bits out?

 

[mr_carman007]

No Title

Number18 - exhaust pipe is what's getting really hot

 

[BarryTurano]

Try removing and cleaning out the exhaust pipe. You may have residual pieces of the impeller blocking the water flow. If the flow is blocked you would get excessive heat build up. You may need to go further down stream, possibly as far as the "Y" pipe. Hope this helps.

 

[Scott Danforth]

You have lack of water flow on that side between the manifold or riser

 

[dypcdiver]

Remove the hose from the hot side manifold at No.13 in the picture and start up your engine briefly.
You should have a good flow, if so then next is to remove one of the plugs No3 in picture on the riser with an Allen key reconnect the hose and again start the engine briefly.
A good flow indicates you have not got a blockage in the manifold or the riser gasket area.
There is a possibility that the annulus of the riser is blocked with rust debris or the connecting hose No10 is not seated correctly.
Have you ever run aground on a sand bank or the like, if so then it could be sand I the cooling system?

 

[mr_carman007]

Today I took between hose 10-20 off, there is water flow there as well as good water flow at 13. The exhaust did get very hot and burned the hoses a little... I am thinking that the heat and the hose expansion is causing part of the issue, number 10 hose is a little swelled.

How much water flow should be coming through the riser into the exhaust pipe anyway? There was a decent little stream however I wouldn't by any means say it was an overwhelming flow of water. Is this normal and do you think a hose replacement would do the trick?

 

[mr_carman007]

So I got my timing light in, but was having difficulty timing it properly with the light (found out why later) so I decided to take it out and time by actually taking it on the water and adjusting as while out there. I got it to go 35mph but couldn't get it over 3500 rpm, it started to get dark so I decided to call it a night. Over the weekend my neighbor came over and we started looking at it again, we found the timing marks on the harmonic balancer and timed it properly with those... boat when timed properly the boat ran like total sh*t. At that point we started thinking that whoever the previous owner had replace the distributor, plugs, and wires had maybe not attached the plug wires to the proper plugs. We re-ran all wires to the proper cylinders and started it up... it is now timed out properly and is running smoothly in my driveway so I am going to take it out tonight and test it, I've got my fingers crossed this does the trick!