90hp "tower of power" reed valve problems

[brokensword]

I have a problem with the reed valve at the bottom carb. Is it true that I need to strip the entire engine to replace the bottom reed valve?

The engine was hard to start and wouldnt plane. So after checking the carbs and getting an expert to look at it thats what he deduced.

Many thanks for any advice / help

 

[jeffersondodson561]

Re: 90hp "tower of power" reed valve problems

What are the compression results?

 

[Chris1956]

Re: 90hp "tower of power" reed valve problems

Reed valves almost never break or fail. On that tower, you need to remove the powerhead and then the crankcase cover and all the connecting rod caps to get at the reed valves. Reed valves usually only affect idle quality.


Why not tell us what the symptoms were? Take a spark test and report the condition of the spark plugs.

 

[Faztbullet]

Re: 90hp "tower of power" reed valve problems

Reed valves almost never break or fail.

I tend to disagree as they break & chip all the time. You will not need to remove rod caps, just raise crank up enough to loosen screws that hold reed block together to replace /repair it
Depending on how the reed is damaged it can result is idle problems,no crankcase vacuum,water in cylinder & poor WOT operation. As posted earlier what are your symptoms other than hard to start and wont plane. This could be a simple sync & link problem.

 

[brokensword]

Re: 90hp "tower of power" reed valve problems

I got compression tested and it was said to be good. The spark is good too. The engine idles well once started and warm. I have not checked for water in cylinder. What is the crankcase vaccum? The engine seems to be running a little too smokey too. Sorry for not going into enough detail before.

I recently fitted this engine to my 17ft boat, and it failed to go on the plane at all. It was also very difficult to start. The carbs were dripping fuel by the time she fired up.

My marine mechanic said about removing all the conrods and crank to get at the bottom reed valve. He said he would not be prepared to do this on my engine due to the expense. I am considering doing this myself instead. If nothing else it would be a learning experience for me.

I am currently sourcing another engine for "spares" as the mechanic said it could be a problem with the bottom carb rather than the reed valve.

I cannot thank you enough for all your comments so far. Trust me, they have been useful

 

[bktheking]

Re: 90hp "tower of power" reed valve problems

Carbs dripping fuel, um they do this if they are choked too much. If they were dripping when you were pumping the bulb and it never got hard then it's a float, needle and seat issue, not reeds. The reed block's have no bearing on compression, the ports are above the reeds. A boat failing to get on plane can be a number of things- bad timing/link n sync, dirty carbs, bad carb adjustment, stator on it's way out, bad switchbox, fuel delivery issue (not reeds) just to name a few. DO NOT pull your powerhead until you rule out all the possiblilities. There is a crapload of info about setting up inlines, search for "Clams Canino's" write up on how to set everything up (link n sync and carb adjustments).

Is this motor oil injected or mix, what mix are you running it at, what year is the motor? When was the last time the carbs were serviced?




Now gas puking out of the carb while running, that's a different story.

 

[brokensword]

Re: 90hp "tower of power" reed valve problems

The engine is around the 1980s. She is also premix. I am only saying reeds because thats what the marine mechanic said, but your right. I should take the time and do my own investigations. He did tell me over the phone that he did some sort of test by blocking one carb off from getting air and see if she would still run.

I will get back to you when I look further at her.

Thanks for the help, keep the ideas flying guys

 

[bktheking]

Re: 90hp "tower of power" reed valve problems

Sounds like he's trying to block off you wallet too. Blocking off a carb is the same as choking it, gas will go everywhere. Maybe you need to get a second opinion or go through it yourself, we are here to help. The only true check is to disassemble and inspect, I got caught with a reed problem too, don't ask