No power after 1500 rpm!

[cnefalcons]

1975 Luhrs 35 Sportfisher with twin Chrysler 440's<br />Problem: Had the 4 barrel carbs rebuilt, after installing them with new base gaskets now no power after 1500rpm. Any increase in rpm above 1500 thru wot does nothing but makes engines sound like they are just bogging down with absolutely no additional power! Any suggestions greatly appreciated. All electrical and fuel pumps in good operating shape.<br />Thanks.

 

[Richard Petersen]

Re: No power after 1500 rpm!

Are both engines having the same problem? Were they running ok, or at least much better, before the rebuilds of them?

 

[Bt Doctur]

Re: No power after 1500 rpm!

If there were running fairly well before, suspect a faulty rebuild ,base gasket leak.inlet filter.

 

[cnefalcons]

Re: No power after 1500 rpm!

Thanks for the quick replies. Both engines ran quite well before the rebuild, only reason for the rebuild was the age and nothing had been done so wanted to try and improve gph. Now I have no power on either engine after 1500, but they do start well!!

 

[Richard Petersen]

Re: No power after 1500 rpm!

Who rebuilt them?

 

[Richard Petersen]

Re: No power after 1500 rpm!

I can think of 3 things. 1-- Rebuilder is very consistant in his work. 2-- Wrong kit was used 3---Bad written instructions caused same error 2 times. 4-- Some 4 bbls are not easy to do because more than ( 1 ) part looks the same as another.

 

[cnefalcons]

Re: No power after 1500 rpm!

Carbs rebuilt by Carbs Unlimited in WA State.<br />Sounds like I need to take them back for a recheck.<br />Thanks for all your interest and quick replies.<br />Happy Holidays, Mike

 

[Don S]

Re: No power after 1500 rpm!

I've had carbs remanned by Carbs Unlimited before, and have never had a problem. For them to both have the same exact problem on 2 different engines is hightly unlikely.<br />I would be more concerned with the timing than with the carbs. Maybe the valves too tight or loose. Hook up a vacuum hose and see what the reading is.<br />How does the engine run at idle? Does it bog down under load only or even when in neutral?<br />Truthfully, if I had some one completely rebuild 2 carbs for me and they both did that, I would have been in their ear immediatly.

 

[trog100]

Re: No power after 1500 rpm!

i got the impression that it was only the carbs that had been rebuilt not the entire engine/engines..???<br /><br />if it was the entire engines that opens up far more possibilites than just the carbs..<br /><br />what about a "common link" between the two engines.. what is there..??.. both engines fed from the same gas tank/line perhaps.. air starvation in a common engine compartment..??..<br /><br />without some kind of "common link" between the two engines both behaving exactly the same does seem very unlikely..<br /><br />if the engines/engines run okay up to 1500 rmp under partial load and idle but wont go above.. it suggests fuel/air starvation of some kind..<br /><br />its possible that the carbs have been bebuilt wrongly by the rebuilder (wrong jets perhaps) but it dosnt seem likely.. course another common link is that both carbs were rebuilt by the same dudes so if one was wrong both might be.. he he..<br /><br />part of the art of diagnostics is working out the difference tween probable and possible.. many things are possible.. but few are probable..<br /><br />in theory the most probable should be the thing to go for first but in practise its usually best to go for the quickest easiest and cheapest first..<br /><br />soooo.. the easiest quickest and cheapest option.. contact the dudes who rebuilt the carbs and explain your problem to em..<br /><br />trog100

 

[DHPMARINE]

Re: No power after 1500 rpm!

I'd pull the carbs and check the base gaskets.Installed wrong or damaged?Sounds like you'r sucking air somewhere,and lacking fuel.<br /><br />DHP