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Kad44p slow transfer from supercharger to turbo

C

Corey

Guest
"New to me boat for about 6 mo

"New to me boat for about 6 months and have been working through engine tuning. I had tiny exhaust leaks and replaced the exhaust after a huge leak on a long trip and finally got the supercharger belt tension correct. Now the engine falls back to lower rpms and sits on the supercharger for a while until the turbo finally kicks in at 2800 rpm where the supercharger goes out. It finally takes off to 3400 rpms. I have just replaced new air, oil, and fuel filters, temp is 190-195 when it is running on the turbo. Once it is on the turbo I can't run it below 3200 or it will drop to 2800 and hitthe supercharger again. I was going to pull the turbo and clean it and possibly the intercooler but I am not sure how or if I should clean the intercooler. I would appreciate any help."
 
"I think You are too heavy on

"I think You are too heavy on the prop side. Get as close as possible to max rpm allowed, around 37-3800."
 
She will turn up past 3400 rpm

She will turn up past 3400 rpms quickly. I don't run it past there but it has hit 3600 when the turbo kicked in before I got the throttle back but I haven't run her on the pin completely. This is also a new problem and seems to slowly be getting worse with time.
 
"Then run a turbo pressure che

"Then run a turbo pressure check and be sure there is no leak on the hose from intercooler to injection pump. There should be a plug with NPTF threads designated for the turbo pressure check. You may need a oil filled manometer for the test.
I do not have the exact specs, so it might be wise to get a manual before You start.
If You have been bothered with 'black smoke' it may be time to clean the exhaust side of the turbo for carbon build ups."
 
Try tightening the serptine be

Try tightening the serptine belt that runs from the crankshaft pully to the water pump. This belt has to have almost no deflection. As compressor is run from water pump pully- when load from compressor is put on it -if any slack at all it will slip causing what would appear to be air pressure problems in intake manifold
best luck
Bob
 
"Thanks guys I will try both s

"Thanks guys I will try both suggestions, I just replaced all the belts 50 hours ago."
 
I think I found it. I did che

I think I found it. I did check all belts and they were tensioned properly. I started to pull the turbo and found that 150 degree elbow on the intake side of the turbo that is routed to the Y pipe coming from the air filter and the supercharger was loose so I pulled it to clean it and the bottom allen bolt is missing. I cleaned the intake side of the turbo which looked good except around the leak. Makes sense at least to me that the supercharger was putting the air through this tube and pushing it back off the turbo intake causing the "gap". Hopefully this is it.
 
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