I was able to order a set of original Solex 142.5 Main jets off eBay. I will be giving those a try to see if I can get the spark plugs that perfect tan color at high speed.
As I was looking and reading I found that most Solex jets are the same and that they are almost the same as Weber Keihin, Mikuni and a few other common carbs. At least they have the same thread pitch. It got me thinking. I had a Weber carb jet kit for my Jeep J-10. I put a Weber 38 on that truck and had some left over jets. 140’s, 150’s, 155’s and a set of 160 main jets in the kit. I did some experimenting swapping them into the Solex 44PA1 for testing.
Remember I am at 4000 feet elevation:
140 slowed the boat from 4200 RPM to 3950 RPM
150 Was at 4150 RPM
155 Was at 4000 RPM
I decided the 142.5 jets, when they arrive will be worth trying out because they would only be slightly leaner than the stock 145’s and that is exactly what I need. It may not help much but I’m going to try.
eBay has a bunch of off brand Solex jets that should work if you want to experiment. I measured the jets at 9mm length, 8mm head width, and a Metric 5mm x .75mm thread pitch.
Another thing tested, I had moved the trim bolt on the 270 outdrive to the third rear most hole for trim. There are only 3 holes for trim adjustment. The 4th hole is for the motor bracket that holds the motor in the locked up position for trailering, I guess. The 4th hole is smaller in diameter and will not accept the larger trim bolt. I was surprised there is not more trim adjustment on this 270.
I lost 1 MPH from 29 to 28 but that was because I had a full gas tank of gas Today. The RPMs remain the same at 4200.
Dwell angle was tested and it is at a perfect 63 degrees. Another thing off the list.
I purchased the Pertronix 2842 Electronic Ignition and the Flame-Thrower 40511 Flame Thrower Coil Package in Amazon. I will update on what that gets me in an increase in RPM.
I’m still not satisfied with the turn out. 4200 and 29 MPH on 1/4 tank is not what this boat should do. It’s not right. It should be faster.
Things on the list to do:
Clean the bottom of the boat
Weigh the boat
New high speed Aluminum Volvo Prop (One of the only props available for the 270 short shaft)
Anyone got ideas on what’s going on here?