Logo
FULL SITE MENU

Want more power from AQ200

M

mtnrat

Member
"I have a 1981 AQ200 with a 28

"I have a 1981 AQ200 with a 280 leg. What is the easiest and or best way to get more power out of this engine. It is currently running fine.
Thanks,
Sean
23820.jpg
My Boat
 
"Change from 2 to 4 barrel car

"Change from 2 to 4 barrel carb (Rochester). Intake manifold must be changed as well. May get You up in the 230Hp range, but fuel economy goes drastically up!"
 
I am a new buyer of a 1994 wel

I am a new buyer of a 1994 welscraft excel with a volvo engine that is seized. I am not sure weather to rebuild it or just purchase another egine. Can anyone give the rookie some help!!!
 
"What engine are we talking ab

"What engine are we talking about and how many running hours does it have? Also, would you be doing the work yourself or will it be done by a marine shop?"
 
"Morten thanks. I figure that

"Morten thanks. I figure that as the easiest. Having talked to my wife, (whose dad bought her the boat new in 1981), it could pull 3 skiers and quickly pull any slalom skier up. Now it can hardly pull up a slalom skier and only if they are exellent at deep water starts. Previous top speed with the same prop was 59mph,now it is 50mph, both at sea level. Could the engine just be tired? I do not know the hours.
Thanks,
Sean"
 
"Sean, I had been about to pos

"Sean, I had been about to post a couple of times asking you what the power rating is for your boat and why would you need more than 200HP to run an 18 footer. It should fly with your current power plant if it is in good condition!! If the boat is now performing poorly compared with a few years ago, I think you should investigate the cause rather than going for a bigger carb. You could start doing a compression test and a leakdown test, it is possible that you may need to either overhaul your engine or have a valve job done to the heads. If all turns well, an idea would be sending your distributor to a shop for rebuilding and checking that the distributor advance curve is correct. A carb rebuild would also be advisable.

Finally, you may want to consider weighing your boat and making sure it is not heavier than it should (this can happen if the flotation foam is soaked with water)."
 
"Great points El. I will inves

"Great points El. I will investigate the engine.
The stringers in the hull were replaced about 5 years ago and it has only seen about 50 hours since then and is housed indoors.
IIRC the boat, trailer and engine weigh in at 3300lbs (on a dump scale). I will call the manufacturer to see what the original weight was.
Cheers,
Sean"
 
"It seems to me that, with you

"It seems to me that, with your engine being rated at 200 HP, you will be exceeding in 20% the manufacturer's maximum recommended horsepower for your boat whenever you are running at WOT . Not a very safe thing to do, IMHO."
 
"I had noted that. However tha

"I had noted that. However that is how the boat came from Campion. With that engine and leg. It is a very stable boat with hydraulic trim tabs.
Thanks,
Sean"
 
"Ok. I performed compression t

"Ok. I performed compression tests, dry and wet. Here are the numbers.

CYL#, dry-psi, wet-psi
1 - 110 - 110
2 - 125 - 139
3 - 102 - 105
4 - 116 - 130
5 - 111 - 120
6 - 120 - 135
7 - 110 - 119
8 - 116 - 126

The factory specs are 142-156psi.
I have a pretty good idea what this means, but would appreciate opinions.
Thankyou,
Sean"
 
"Oh and I forgot to say some c

"Oh and I forgot to say some cylinders went from 0-50psi on the first compression, others from 0-75psi. Then they would go to near 100psi on the second compression, and get full readings after 5 compresssions.
Thanks again,
Sean"
 
"Try a leakdown test before yo

"Try a leakdown test before you go any further. If the leaks are through valves, a head job (a few hundred bucks) will probably do. However, if the leaks are through piston rings, then you are ready for a rebuild (a couple of thousand bucks, less if you do it yourself). If this is the case, I know of a few people that have swapped their 305 for a 350 when going for fresh power; this is not to obtain more power, but because the 350 blocks are more common and therefore they are cheaper (and so are the components)."
 
"Thanks for the reply. I will

"Thanks for the reply. I will try to get hold of a leakdown gauge this weekend. I live in a small town and no tool shops carry them. I may be able to borrow one from a neighbour if he has one. If not I will get my mech to do one for me. I see your point on the 350. I am not worried anymore about more power as it was adequate in its time, and the lack of power is not because of the engine itself, but rather its tired condition.
Thanks,
Sean"
 
"Thanks, I was looking at the

"Thanks, I was looking at the leakdown testers on line and my mind was thinking that replicating what it does should not be so difficult. Great link.
Sean"
 
Back
Top