Johnson 235 Exhaust Filler blocks melted

wildwebb

Recruit
Joined
May 13, 2012
Messages
2
I have a 1981 Johnson 235 Model J235TLCIB. I got the boat from my father in law. He said the overheat alarm had gone off at the end of last season. I picked up the boat in August. I replaced the impeller, and it was still overheating. Tore off the exhaust and discovered the filler blocks had been damaged and partially melted. He said it had been running rough when first taking off but fine once up to speed. I assumed the carbs needed adjusted but now I'm sure they were running lean.

Ive read in another thread that the exhaust filler blocks are not needed for the 115 if the WOT is set around 6000 RPM. Is this an option with the 235? If so what else needs to be done? Larger needles for the carbs? Prop pitch change. or do I need to replace the exhaust filler blocks.

I know I'll be rebuilding the carbs. The compression was ok but not great ,90 -105. I'm this far and will probably remove the heads and check out the cylinders.

Im open to any tips. I hate to loose the remainder of the fishing season but would rather do it correct.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Johnson 235 Exhaust Filler blocks melted

The V-6 will run okay if they are damaged but the V-4 will burn a piston if you don't have them.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Johnson 235 Exhaust Filler blocks melted

The v6 exhaust filler block kit 392001 may still be a special order item from Bombardier. There are a few dealers here in the US that still have new stock on that part. As you check your cooling system, pull the head covers off the heads and check to make sure the cooling passages are clear. Also, when you have the heads off-check the passages aroung the cylinders. Check the rubber water deflectors by each cyl to make sure they are still located properly and are in good condition.
 

wildwebb

Recruit
Joined
May 13, 2012
Messages
2
Re: Johnson 235 Exhaust Filler blocks melted

Thanks for the replies. I'll be working on it this weekend if the carb rebuild kits arrive.. Intake looked good. I'm going to put back together with out the exhaust filler blocks and see how it runs.
 
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