I recently acquired a 1986 Phazer. The sled will bog down off idle, just when the clutch begins to engage. I took the carbs out and thoroughly cleaned them. The problem seemed a little better, but it was still hard to get the sled moving. I was on my back lawn, so I realize it was taking a little more power than normal to get it going. I checked the compression and I can't remember if it was 90 lbs each cylinder or 70 lbs. Since it's about 100 outside I don't want to go pull the rope, but I'll check it again later tonight. I wasn't sure at the time what the compression should be; however, I was happy that it was even between the two. I live at about 4500 feet. Even if it is 90 lbs, which is the highest it could possibly have been, is this to low? I assume 70 is way too low. I am technically capable of installing new pistons and rings if it needs the top end redone. When you install new pistons and rings, do you need to hone the cylinders? Where would you buy the pistons and rings if this is in fact the problem?

Thanks for helping this noob sledder,
Todd

The sled is jetted for winter, probably +20 to -20, it won't run in 100 degree temp. but either way it should have at least 125 Lbs. compression.
Yes hone them, and adjust the ring eng gaps if installing new pistons.

Don

It felt a little rich, running better without the air filters. The local shop had jets that were 2 steps leaner which I tired, but it didn't solve the problem. That was when I started thinking about the top end. Since hot air is less dense I would assume that is why it seemed a little rich. Luckily it doesn't stay near 100 all day, but you point is well taken about the jetting not being for this weather.

Todd

The whole circuit will be over rich, 2 sizes down on the mains in the summer isn't enough, at least 4 sizes would be needed.

I'm going to order some pistons today. I have a drill mounted cylinder hone, would this be sufficient for honing the cylinders? How much honing is enough?

Thanks for the great info and quick replies,
Todd

You best "Mic" the cylinders 1st. someone may have bored oversize already.

Stock bore is 72MM or 2.834".

Before I took the head off to mic the cylinder I checked the compression. I got 110 pounds. Is this still too low? Would it cause the problems I related earlier? Honestly I was hoping for 70 pounds so I would know for sure that was the problem. When I saw 110 I was annoyed. The sled has 3500 miles and the cylinder is exactly 72 mm so it has never been overbored. I don't know if the top end has ever been redone or not, I would guess not.

It should run with 110 Lbs. but if your tester is accurate, it's still somewhat low.

Don