Installed Mikuni and BPS exhaust. Runs great, alot more power and top end speed. Went from 22mph to 26.5mph, 22mph with one person and gear. WOT rpm's are 4200. When running at night, exhuast glows red hot! Not just a low glow, but a bright orange as if it's going to melt off. Is this normal? BPS says yes.
23hp GTR
16/48 Surface Drive Boat

Must be purdy!

my bps crossovers just cracked. not on the flanges but at the 3"x1-1/2" reducer. That is what happens when u grind or machine down welds to try to make it look pretty or cover up dog sh!t welds. from getting cherry red hot like u talkn about and it hitting water or cooling way too fast the metal stressed out and had no reinforcment to back it up.

other than that i love em!!!!

when I set valves, I didn't go 1/4" past tdc. Just turned crank until valves were fully open. Could feel top of crank, flat spot. Could this be wrong? Unburnt fuel in exhaust?
Also, have a little fuel coming out of valve cover breather tube.

sounds like a lean mixture.
anyway to richen it slightly?

Even if enrichining it slightly decreases horsepower, it will be better on valves and exhausts

going to set valves and try friday morning. I will post results. thanks

I would fatten it up a little. Sounds too lean to me.

My Hopkins really glowed and my MM does some too. According to my plugs I'm on the rich side.

Carb came from BPS and has 190 written on the bottom. It will stall out at full throttle. I run it about 3/4 to 7/8 open. A local motorcycle mechanic said it sounded like it was running too rich and I could adjust it by moving the "E" clip. ???????????????????????
I don't think this red hot exhaust is normal, the K&N is starting to melt.

I been running the marshmello muffler!! The first one i had glowed cherry red also, from the flanges to the tip.. I didn't think it was right and after only 4 hrs it broke 4 differant welds.. The one i had was one of the proto types that they sent gt .. We think they had to much restriction in it.. The new one i have hdon't glow hardly at all and it is doing just fine.. I find it has a little more power also.. But since the other one i have went from a 160 jet to a 170.. Now it runs a little rich but a hell alot better!!

i'm trying to set my valves again. When I get to 1/4" past tdc on the compression stroke, do I set both the exhaust and intake valves at .005 at the same time?????

well I set valves right this time and it ran a little better (out water until friday). I noticed I had a exhaust leak. My friend put the exhaust gasket on wrong. I fixed that and WOW!!!!!! This thing runs so smooth!!!!
No more poping, backfiring, blue flames, or nothing. SWEEEETT! I will run in morning and post results saturday.Thanks