Me and 5 of my friends decided to buy a boat as an summer project (Yes it was a big mistake lol), but now we have everything done, new plugs, electrical, lines ect...So for the first time we take it on the water, and we rev to about 1500 RPMS it starts to shake and past a certain point it'll backfire and pop and refuse to rev higher. Any ideas? Thought it might be from the Carb being too lean? Or fuel pressure? Its a 2.5L I4 Chevy with a 1BBL..Thanks! It also has a hard time turning over right after, we have to wait an hour or so for it to be able to turn over.The revs it was able to obtain got worse and worse
08-17-2012 09:06 PM
Cross firing the plugs in the dist cap? Or, wrong firing order?]
08-17-2012 09:11 PM
Timing way off.
08-17-2012 09:15 PM
No the firing order is right, and we had to take it to a mechanic at one point and they said they did the timing on the dot...So I dont think that timing is an issue, it runs like a clock at idle speeds, before it stalls at higher RPMS
08-17-2012 11:04 PM
Weak or improper vale springs.
08-18-2012 01:04 AM
can't delete this
08-18-2012 01:36 AM
If it were mine this is what I would look into, old gas, plugged fuel filter or dirt in the carburetor. You said you put new plugs, I would hope when you say electrical you mean cap, rotor and plug wires, (ignition parts). If not, that to.
08-18-2012 09:39 AM
possibly incorrect lifter preload.
08-18-2012 01:41 PM
Alright..Thanks guys for your input! Were going over to the boat today and will just do a quick run through of items that you all said.
08-18-2012 02:25 PM
I would take a WAG.......old stale gas!!!
08-19-2012 06:28 PM
Does it have enough oil?
08-19-2012 07:06 PM
it has oil and a tune up. the gas is new too. we took of the distributer cap and one of those 4 brass things had broken in half. Could that be it?
08-19-2012 07:07 PM
And its turned on before, but the mechanic that we hired took it to his shop and lifted the engine out and it ran good, but its progressively getting worse, now it wont even turn over.
08-19-2012 07:33 PM
The outdrive unit is freezing/siezing up.
08-20-2012 09:45 AM
Has the outdrive been services? Does it have the proper lubricant? Do you have the proper...propeller? It sounds like its not the engine. If you blow the outdrive completely; its going to be a bad day. Take the boat to a marine mechanic and have them inspect the O/D. If you guys are fairly equipped mechanically, you can do the service yourself. Id see if theres a copy of the service manual on the web, and see if its something you want to tackle.