Mystery Stop

[Captain Rick]

details:
1996 GTX New engine (787) from PGC less than 3 hours
rebuilt fuel system new hoses and new selector valve
new raves
new rotory valve
new jets in Carbs (mechanic done)
carbs synched
Block off plate installed current tank at 24:1 premix
New Battery
Problem:

Runs great and last all day UNDER 6000 RPM Engine Temp was below 85 all day by the guage, but the head was very warm to the touch.
Water is coming out of the overflow at tow hook and is warm to hot
if I go over 6k RPM the engine will run for about
30 seconds then shut down
It acts like you just pulled the cord off.
If I try to restart it acts like a dead battery clicks into solenoid but cant seem to turn engine over.
If I sit for 15 min then it restarts just fine and will run UNTIL I try to go over
6000 RPM.
I ran it for over an hour today below the 6k threshhold, but coming back I tried to go over 6k , ran it at 6100 and it died after about 30 seconds

Anyone have any ideas? I am at a loss here

Rick

 

[Wheels & Waves]

Next time it quits and you are not able to start it, check to see if you can turn the pto over by hand or if the motor is locked up. Your engine could be seizing. Also, check your plugs when this happens. If you have light grey, you are lean. If you pull the choke partially out at your trouble rpm range and it pulls through the trouble spot, your too lean. Check the settings on the carbs. You could have a fuel restriction.
BTW, 24 to 1 mix may be a little much, depending on the type of oil you are using. Syn oils should be around 36 to 40 and be a low ash non TC-W3 oil for the 787.

 

[Captain Rick]

I forgot to mention running 24:1 because its breakin period still on new engine Sry but the other ideas I will try soon thank you
Rick

 

[seadoosnipe]

Quicksilver oil

The Quicksilver low ash, non NMMA oil, both synthetic or regular blend can be used in the Rotax engine. I buy it from Wal Mart. The price of the regular stuff at the dealers was hurting my wallet!......
But, if your using one blend or the other, I wouldn't swap types. I did read and write an article on the syntetic vs. regular blend oil last month for the forum. Good luck with the break in and hope your engine pans out o.k.!
Good adivce Don....

 

[D 5UPE]

details:
1996 GTX New engine (787) from PGC less than 3 hours
rebuilt fuel system new hoses and new selector valve
new raves
new rotory valve
new jets in Carbs (mechanic done)
carbs synched
Block off plate installed current tank at 24:1 premix
New Battery
Problem:

Runs great and last all day UNDER 6000 RPM Engine Temp was below 85 all day by the guage, but the head was very warm to the touch.
Water is coming out of the overflow at tow hook and is warm to hot
if I go over 6k RPM the engine will run for about
30 seconds then shut down
It acts like you just pulled the cord off.
If I try to restart it acts like a dead battery clicks into solenoid but cant seem to turn engine over.
If I sit for 15 min then it restarts just fine and will run UNTIL I try to go over
6000 RPM.
I ran it for over an hour today below the 6k threshhold, but coming back I tried to go over 6k , ran it at 6100 and it died after about 30 seconds

Anyone have any ideas? I am at a loss here

Rick

Is it not just an overheating issue you have?
Even if you have a higher oil mix in there. Your carbs could be set at an over lean mixture.
This would cause overheating due to the lean mix on detination.
Just a guess Rick but could be you just need to give it a rich fuel mix at the carbs.
Let us know if you get it sorted.

 

[Captain Rick]

I pulled the plugs no gray ash just a light oil covering a little black.
Went thru every wire connection, all good. The cover on the pressure valve on the muffler box was on crooked. Water got into it, so I cleaned it and checked for damage, none found, I closed it up correctly. During the last run I tok the seat off to watch it, using transpaerent fuel lines now so I could see fuel to the engine was perfect, but aft the the shutdown whenI restarted I could see air bubbles in the return line from carbs to tank. After a few minutes they were gone and it was full again. I know I am chasing a gremlin but I would like to fix this.
Engine water temp ws 85 when it shut down. Best way to describe it is like pulling the cord off, the engine just losses rpm then dies and the elecrtronics shut off. I have to pull cord and wait a few seconds and put it back on. I also noticed that the alarms doesnt always sound whe you connect the DSS.
Rick

 

[seadoosnipe]

Dess

I'm having a problem similar to this in my boat. I'll be out cruisin, full speed and it just shuts down. Like you, I don't get the double beeps when removing and putting my lanyard cap back on. After a few times, I'll hear the beeps and then the engine will start.
With the DESS post working off magnetics and the chip inside the cap, I'm going to replace my cap and post. I'll have to take it in after replacing them though, I don't have a MPEM programmer.
I think you may be having the same type problem.

 

[Captain Rick]

Snipe yours may actually Electrical , inside the cap it ahs 2 contacts that must make a connection,
Mine is a seizing engine at 6k RPM No doubt about it / sux
Oh well its under warranty justthe thought of takeing
out and short blocking again bites
The life of a Jetskier :rofl:

Rick

 

[seadoosnipe]

hmmmmmm

I see Rick. I read the last couple responses to your query and for some reason, went into my post and lanyard. That's my problem no doubt. I found a used mpem programmer that I'd like to have, but I don't know if my wife will be happy about me coughing up 1k for it......oh well.
Yeah, I just read your post from the top down and I doubt it is your lanyard post....
Kinda strange you can run for long periods under 6k and as soon as you go over, it seizes. Seems like if something in the engine was astray, it would seize no matter what the rpms were..........
Hope you get to the bottom of it!........:banghead:

 

[Wheels & Waves]

Seizing engine

Rick,
Pull your Rave Valves out and look into the cylinders. If it has been seizing, you will see scoring above the exhaust ports. Your reman may have had the piston to cylinder bore clearance a little too tight.