sandyxr6

hey im new on the forums and in desperate need of pointing in the right direction just bought a ski boat with a 351 cleveland in it and and since taking it out on her maiden voyage it would rev out too 4k rpm it wouldnt hold its revs constant and taking it out recently again after giving the holly a clean it would jus lose all its guts after 3000rpm as in id try and rev it and it would just not rev any more and revs would die off as if it were choking its a great engine and i wont own anything with a chev or holden badge on it its been rebuilt 2 yrs ago because it threw its crank was rebuilt with a 4ma crank forged pistons mild cam and a 750 vac secondary 4 barrell holly from what i understand this should be a pretty powerful engine specially in a boat i was starting to go down the lines of a vac leak a faulty carby or the timing is out i wanna learn too look after this engine i just not shaw how to check all this stuff any help would be hugely appreciated thanks

George1861

How does it run in neutral vs forward? If runs on up in neutral & not in forward you may have the wrong prop. Other possibilities are ignition or valve springs.