hydroscooter
Recruit
- Joined
- Jul 30, 2019
- Messages
- 2
Hey guys!
I've been working for a month or two in my spare time to get my old boat back on the water. Still having some engine issues, thought I'd share and try to get some feedback. It's a 1984 Glastron CVX-17 with 1978 Mercury 115. Sorry for the long winded first post, just want to make sure I'm covering the important details.
Last year I had the boat out a handful of times and it always ran great. I didn't have a tach at the time but there was no missing at any RPM and it would run 45MPH all day. I had some issues with the interior of the boat so it wasn't used as much as planned.
Fast forward to this year, I get it out of storage and put a battery and muffs on it, it won't start. This is where it all started.
I get the seloc online manual and start troubleshooting. I find that I cannot make the coil spark by simulating the trigger signal and decide to replace the ignition with a new unit from CDI. While wiring the new ignition up I realize the wiring going into the trigger is garbage and there was no saving it. I replace the trigger as well as the external wiring harness while I'm at at. The stator and internal harness had been replaced the year before. With the new electrical components I was getting spark, but still not running. I decide to rebuild the fuel pump and carbs and finally get the engine running. It sounds great on the hose so I changed the lower unit fluid and water pump impeller and head to the water.
The engine starts and idles well, launches and planes up quickly, but will not go over about 3500RPM without missing and tops out in the mid 30mph range. I have no acceleration after 3500RPM, but a good way to go with the throttle. There has to be something I did to this engine while "fixing" all these issues to cause this. Here is what all I've done since getting it back on the water:
1. Went through carbs a second time
2. Went through link and sync procedure multiple times
3. Verified timing with a light
4. Switched from a 19P prop to a 17P prop with zero change in max RPM
5. Disconnected rectifier output to battery
6. Tested compression, all 6 even and within a couple psi of 125
7. Removed back drag tubes from carbs for one ride, this lost a couple RPM and made miss come on a little sooner
8. Tried new plastic external fuel tank, not much difference, might have gained a little RPM
Losing a little RPM with the back drag removal makes me think maybe I am running too rich. It's my understanding that the back draft tube pulls a small vacuum in the float chamber at mid range, leaning it out and using less fuel. I know a lot of folks run without them but since my engine ran so well last year with everything in stock form I decided to try it stock first and adjust from there.
Is there something obvious I'm over looking here?
Thanks in advance!
I've been working for a month or two in my spare time to get my old boat back on the water. Still having some engine issues, thought I'd share and try to get some feedback. It's a 1984 Glastron CVX-17 with 1978 Mercury 115. Sorry for the long winded first post, just want to make sure I'm covering the important details.
Last year I had the boat out a handful of times and it always ran great. I didn't have a tach at the time but there was no missing at any RPM and it would run 45MPH all day. I had some issues with the interior of the boat so it wasn't used as much as planned.
Fast forward to this year, I get it out of storage and put a battery and muffs on it, it won't start. This is where it all started.
I get the seloc online manual and start troubleshooting. I find that I cannot make the coil spark by simulating the trigger signal and decide to replace the ignition with a new unit from CDI. While wiring the new ignition up I realize the wiring going into the trigger is garbage and there was no saving it. I replace the trigger as well as the external wiring harness while I'm at at. The stator and internal harness had been replaced the year before. With the new electrical components I was getting spark, but still not running. I decide to rebuild the fuel pump and carbs and finally get the engine running. It sounds great on the hose so I changed the lower unit fluid and water pump impeller and head to the water.
The engine starts and idles well, launches and planes up quickly, but will not go over about 3500RPM without missing and tops out in the mid 30mph range. I have no acceleration after 3500RPM, but a good way to go with the throttle. There has to be something I did to this engine while "fixing" all these issues to cause this. Here is what all I've done since getting it back on the water:
1. Went through carbs a second time
2. Went through link and sync procedure multiple times
3. Verified timing with a light
4. Switched from a 19P prop to a 17P prop with zero change in max RPM
5. Disconnected rectifier output to battery
6. Tested compression, all 6 even and within a couple psi of 125
7. Removed back drag tubes from carbs for one ride, this lost a couple RPM and made miss come on a little sooner
8. Tried new plastic external fuel tank, not much difference, might have gained a little RPM
Losing a little RPM with the back drag removal makes me think maybe I am running too rich. It's my understanding that the back draft tube pulls a small vacuum in the float chamber at mid range, leaning it out and using less fuel. I know a lot of folks run without them but since my engine ran so well last year with everything in stock form I decided to try it stock first and adjust from there.
Is there something obvious I'm over looking here?
Thanks in advance!