I recently installed the Vitos 240 Kit on my Blaster that I bought with a new crank from Vitos with new bearings, clutch kit, jet kit, cone filter, and they also ported the head. I rode it a few times to just break it in lightly for a week and then took it out on a long ride over th weekend when the problems started hapening. The first thing i noticed during the break in period was that higher up in the rpm's the engine would sound something like it was detonating but im wasn't sure. But during the long ride over the weekind the it died on me about two times and I just had to let it sit for a little and it started right back up. And then it just finaly gave out and just siezed up. Im new to Blasters so im not knowledgeable on what is going on, but im guessing that i need to run race fuel because i've been running on 93. And i've also heard lots of bad things about the piston that comes with the Vitos kit. Help me out!
Help with 240 Kit
- Thread starter Vay23
- Start date
Yea, your jetting is a little lean, and you should run your mix a little thicker for the first coupl tank fulls of gas too.
What size and what carburetor, are you using? What main jet size are you using? What was the cranking compression before the piston seized?
With the Vito pistons and several others, the best thing you can do is to eliminate any stress risers by using 280 grit emery cloth to roll over all sharp edges. There should never be an edge around the circumference of the piston crown. I actually glass bead the piston crowns with light media abrasive.
I would also recommend doing a pressure check after a rebuild. The test would be 5 PSI for five minutes. The engine should not drop in pressure before 5 minutes. The exhaust port would need to be blocked off, and the piston close to BDC.
With the Vito pistons and several others, the best thing you can do is to eliminate any stress risers by using 280 grit emery cloth to roll over all sharp edges. There should never be an edge around the circumference of the piston crown. I actually glass bead the piston crowns with light media abrasive.
I would also recommend doing a pressure check after a rebuild. The test would be 5 PSI for five minutes. The engine should not drop in pressure before 5 minutes. The exhaust port would need to be blocked off, and the piston close to BDC.
This is typical of the Vito stuff. The jetting needs to be so rich in order not to melt the piston that the preformance is sacrificed.
im not sure what the specs of the compression and stuff was when the rebuild was done because all of the work was done by a local shop but they are running a 310 main jet in my stock carb. Also wanted to add that no damage was done to the cylinder sleeve at all just the piston which had a huge hole at the top of it.
M
Mass-Blaster98
Guest
The hole in the piston is from detonation, what octain rating fuel were/are you running!??
I ran a 390 main jet in my 72mm cylinder with the stock carb.
I ran a 390 main jet in my 72mm cylinder with the stock carb.
yeah, i would say your lean, im running a 310 with just a pipe reeds and port, so with a 240, you should be way higher like close to 400
Thats exactly what i was thinking. I was running 93 octane when it blew, do you guys think tha i should be running race fuel?
