Got some BRP tuner on the way. Should be here friday. Hopefully this will fix it up. Does can have instructions on it?Originally Posted by ChampioNman
Got some BRP tuner on the way. Should be here friday. Hopefully this will fix it up. Does can have instructions on it?
Yes sir. Do not do this in your driveway.....it will turn black....do not let it sit in the motor more than overnight.....take her out the next morning and run her good.
UPDATE:
Done the decarb and may of gained a pound or tow of compression but still about same numbers. I put ficht reed cages with chris carson reeds in also. I rechecked floats while i had it apart and the floats are correct. I took boat out and same thing, about 4800 rpm and 42 to 43mph. While at 4800rpm i pressed in choke to get more fuel and the engine started to bog down. So i dont think its fuel issue. Check the plugs when i got home and they all looked good. Boat is going to marine mechanic shop this evening.
One thing i did notice was that when running on muffs and putting my hand over the carb with lower compression (bottom one on passenger side) it didnt suck my hand up towards carb good. All the other cylinders would have really good suction and the engine would start to stall as soon as i put my hand over it. The lower compression cylinder had weak suction and would take quite a bit longer to start stalling the engine.
Any thoughts on why that one Cylinder didnt have near the suction as the other cylinders?
I would have said reeds but seeing you installed new cages and reed, I'll ask this question,,did you install new intake gaskets when you installed the new reeds.
I put new gaskets between the intake and block but not the spaghetti o-ring.
For grins, move the carbs around and see if anything changes vacuum wise on the front side.
Took the boat to marine shop a week and half ago. Just heard from the shop. This is what he told me.
Compression issue:
He checked compression and at first the top cylinder on drivers side was 135lbs. He thought gas or water was in cylinder but there was nothing. He check again and it was 120. The middle cylinder on drivers was 100 and bottom was 90lbs. The passenger side was top 95lbs middle 90lbs and bottom 85lbs. He then said that compression was erratic and he kept getting different numbers each time. He said that maybe a sealing ring on crank was broke and letting compression go from cylinder to cylinder. (i dont understand this). He also said that the compression on this motor should be close to 120lbs.
He stated the bottom two carbs didnt have near the vacuum as the other carbs did.
He stated that these blocks was bad to crack and let water inside the cylinder causing loss of power and loss of rpms. He stated that steam was coming from engine when he ran it leading him to believe the block may be cracked. He didnt say where the steam was coming from. However about a month ago i made a long run and i did notice steam coming from the pee hole after the motor was shut off.
When running he checked temp of heads. All the temps was 180 degrees except the middle cylinder on passenger side and it was 108 degrees. He thought that cylinder wasnt firing but couldnt find anything wrong. He stated he tested the heads again warm numerous times and all was 180 degrees.
He is going to check timing and do a leak down test monday. Then we are both going to take the boat to lake monday evening. He advised more than likely it was going to need a motor. He stated that most of the rebuilds of these motors dont last a year due to the blocks cracking. He acting like a machine shop couldnt check the block for cracks and suggested if it was the timing then i would be better to buy another motor.
Everything else checks out so far. He stated it idled real good on muffs and sounded good.
When i dropped boat off to him i explained that if it needed a motor that i was going to rebuild this one myself and just wanted him to try and diagnose any other problem it could be other the needing rebuilt.
Questions:
I heard the early 90s blocks had some flaws and was prone to cracking. Is the same true with the late 90s blocks?
Is it possible that the crank sealing ring could let compression pass from cylinder to cylinder causing different compression readings?
Can a machine shop check block for cracks?
Sorry for all the questions buy I know that you guys on here really know your stuff and will give honest advice.
In the early days of the motors, a flaw in the lost foam mold would cause a "pocket" in the #1 piston area. An easy way to tell would be to look at the #1 piston top and see if it had been steam cleaned. That's a sign of water intrusion. Head temps should be in the 140* area, so either that is a false reading or there maybe thermostat issues. He could have quickly checked the spark on that cylinder by either pulling the plug wire and seeing if the engine's running characteristic changed or putting a timing light on it. It is common to see the bottom two cylinders lower than the upper 4. He needs an ignition analyzer to check timing.
If he doesn't have the ignition analyzer, he can use yours.I'm not quite sure why he would say if the timing was off, you would be better off with another motor. I see a lot of variables in his testing, a leak down test should have been done before now. I personally never found a broken seal ring, that doesn't mean it can't happen, I would think reeds before a seal ring. I know you replaced the reeds, do you think there may be any problems with that? By the way, spark test should be done with the spark plugs installed, so to be at normal cranking speed.
I had a broken seal ring in a motor a few years back but when it happened, I knew it pretty quickly(noisy), ran very badly and caused block and crank damage. Like Jerry says though, pretty rare.If he doesn't have the ignition analyzer, he can use yours.
Age and treachery will always overcome youth and skill !!
I actually took the easy timer with me and offered to let him use it and he stated that he didnt need it. (Doing it the hard way then i guess) When i checked timing it was within 1 degree, whoever i was not able to confirm the pointer was in the correct position due to not having piston stop. As far as reeds go, I checked for light to pass through and the seating against cage and it looked good. The old reeds actually looked good and let very little light through. If he cant figure it out then i may swap reed cages to different places and see if it picks up more vacuum then. I thought seal ring would be very noticable and cause tons of damage just like omcforever said his did. He stated not to rebuild it cause of the blocks cracking so much on these engines. Everything i have read about these engines has been they are very good and reliable.If he doesn't have the ignition analyzer, he can use yours.
He kept stating that the vacuum was way to low on bottom two cylinders. Which i thought would mean worn rings or reeds.
My motor has been doing this since early spring so i would think it would be very very noticeable if seal ring was bad or broke by now since yours was noisy and caused damage.
Was any work done on your motor prior to this problem starting?
I put lower unit (with new water pump) and hot foot on it last summer. Ran it all fall after lower unit and hot foot was installed and it was running mid 50s with full tank of fuel, live wells full and passenger. It sat all winter. I did raise prop to pad to 2.75 inches during winter since it was at 3.5 inches, replaced theromstats, thermostat springs and changed primer bulb. Ran it this march and april but was so cold and water was rough that i didnt run over about 35mph. Went out first of may and it started missing, running super rich and 4800 rpms. Thats when i started with fuel system and so on. I did lower prop to pad back to where it was when i got it but didnt change top end just hole shot some. Things i know was bad that i fixed was carb bowls warped and leaking, fuel pump was leaking into the pulse limter, clear roller sleeve and i replaced cold start/temp sensor (realized when working on it that it was staying in cold start).
JMHO, you may know more about working on this motor than your mechanic. If he knows how to do the leak down test it may give you your answer.
I will post tomorrow night what he tells me about the leak down test and what he says about the timing.
Main jets good and tight?
Yeah. Triple check jets.
So went and got my boat today. I get there and the mechanic said the timing was good and the leak down test was good. He stated that he took the boat out this morning and it pulled up to 5600rpms and done perfect. So we went to lake and sure enough. It was pulling 5700 rpm with over quarter tank of full, me and 400 lb driver. It was running 54mph with an old 23 pitch prop i put on it. He insisted that he done nothing but check compression, check link and sync, leak down test, spark test, checked timing and checked temps. Mechanic said the prop i have on it now is not a performance prop caused its coned out at the end and wasnt lifting front of the boat good when running and to put the 24 raker back on and it should run better.
So the last time boat was on water was it would only turn 4800rpm with me and my wife at about 44mph. I didnt run the boat too long though. I just ran it about a half mile, shut her off and fished for an hour then ran it back to the ramp. Only thing that i done after last time it was on water till i took it to him was remove carbs cause there was a little fuel in two of carbs and checked floats again (one was slightly off). I also pulled intake to install new intake to block gasket that i had been waiting on.
So im stumped. I done the decarb the day night before i went to lake when old reeds was installed. I installed new reeds next day then went to lake. Only things i have done recently was adjust floats, reeds,reed cages intake gaskets and decarb. Could it of actually been reeds and i just didnt run it long enough on the water to fully finish the decarb? Or maybe the intake gasket had been leaking the whole time? But its finally fixed now. You guys have any idea of what may of happened?
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