86 Johnson 225 VRO Carbs

[fission]

Been chasing a high RPM miss for quite some time, checked everything possible electrical, stator, timer base, coils, wires, cdi boxes, shift switch, harness's for possible shorts, fuel tank, lines, vent, bulb etc... my dealer went through carbs last fall, all this and still the same, 3500 rpm and it starts missing and falls on its face, some days if lucky will get 4200rpm, last night I pulled the carbs and found 4 of 6 have cracks in the venturi tubes going from the bottom of the tube up past the tiny holes that are drilled in them, if I understand how these work they are drawing gas up out of the bowl on a vaccum , right ?? if their cracked their not getting the corrcet amount of gas. I'm in the process of rebuilding all of them, I have 6 carbs for parts and hopefully this is the fix, has anyone seen this and am I on the right track with this ?? THANKS in advance, really learn alot from this site, very lucky to have so many knowledgable people willing to share their time and expertise.

 

[Brew2]

Re: 86 Johnson 225 VRO Carbs

Hi Fission,<br /><br />Sounds like you are on the right track....those tubes can be a real pain. The plastic they are made of can start to break down over time due to additives in the gas. I've been told by some that they have had success in getting replacement tubes by having a friendly dealer call Bombardier on their behalf. I've tried and had no success at a couple local dealers here in Calgary.<br /><br />While you've got your carbs apart anyway, I'd take another real close look at the high speed jets located in your float bowls. A partially clogged jet or two would give you the symptoms your having.<br /><br />Good luck.