Rev limits at 300rpm and engine bogs downs

Vehicle using water or overheating?

It could be a plugging of the cat convertor.

Another place to look is at the timing of the engine. Do you get a pgm or check engine light?

Hmm plugged cat. So to check this out could you temporarily disconnect the exhaust to see if there is any difference and recheck the RPM's. I did check the sparkplug and they were quite black and carboned up. Timing has also crossed my mind, I am struggling to find the timing marks on the Honda Prelude 1989. Could there be anything also wrong with Distributor?

Thanks

Disconnecting is a good means of diagnosis. That was why they made by-pass replacement pipes. Not intended to permanently replace the cat. I doubt the distributor is the issue. It is firing and trying to do its end of the deal. How about the coolant use question?

Not sure about the history of the vehicle. Trying to understand why you are asking about coolant problem. I dont' quite understand the relationship. Not sure about the llites. What is a PGM lite?
Thanks in advance for you info

Some of the older vehicles did not have check engine lights but rather a PGM-F1 light. This indicated that a problem existed with the car and you could pull a code from the computer to help track the source of the problem.

The coolant level is an indication of internal problems with the car. This could include the possibility of a failing head gasket or a cracked head. These can have an impact on the ability of the vehicle to reach full potential on rpm or speed.

We disconnected the cat and exhaust on the Honda, but still no sucess, still bogs down at 3000 rpm. Will watch a little closer if ony thiing leaks with coolant. I will maybe try to do timing and see.

Still have problems with the engine rev limiting. we have also have tried adjust the time but still no sucess wondering if the distributor needs replacing, could that included the coil etc.

Fuel injected or carbed? Have you checked the air intake system for plugging or replaced the air filter?

It is a carb engine. Yes I washed the air filter, new spark plugs and the fuel pump has also been replaced.