Reed Question

[mamm7215]

I'm going to do the thermostats on my '81 90hp and I'm thinking of taking off the power head to do it. While it's off I'm going to check the reeds, I suspect a possible bad one due to cylinder 1 running a bit lean with clean carbs (really clean). It's been overheated by a previous owner but the compression's good (118-120 all four) and runs and idles good. I've got the remains of a same year 140hp. It blew a cylinder the week after I got it and I have the intake and reeds from it which are in very good shape. I'm wondering if I can just swap the intake/reeds from the 140 to the 90. The parts book says the reed assembly is the same part number but what about the filler blocks? Anything else to consider?
Thanks.

 

[DargelJohn]

Re: Reed Question

Never done a bubble back V4, but I think you can do the T Stat job without pulling the powerhead.

Reed valves tend to leak when they fail, causing a rich condition. If the 90 and 140 reed blocks are interchangeable, I would rebuild the 140 reed blocks and use them in the 90.
- Dismantle the the reed blocks.
- 400 grit wet/dry paper. Wetted surface, do figure 8's on a very flat surface to index the reed cage surfaces.
- Inspect the reeds for any imperfections.
- Use a small drop of Blue Loctite on the screws. Don't overtighten.