plugs/bogging questions

[EXPERIMENTAL]

Last weekend was the annual ozark invasion free ride at the LOTO. I got some interesting ideas on how to make my boat better on low end because i am having bogging problems, I've been told pop off might be the problem, jetting, tuning etc. i realize that may be the main root of the problem. I plan on going single 48 by next summer, but right now i don't have the time to do the work, plus i don't want to hinder my ride time for this summer. Basically i was told to use a different plug. instead of the common BR8ES that is recommended for the superjet, i was told to use a BP8ES which is exactly like the BR8ES except it is slightly elongated to get a better spark down closer to the combustion mixture (only about 1-2 mm) Does anyone run this plug, and if so did you see any improvement. (I have a protec girdled head with 35cc domes, moto tassinari reeds, and dual riva pro series 48 carbs ) I know re-jetting would help, but since im going to be changing my set up over winter anyway, i don't want to re-jet twice, i just need a quick fix for my bogging issues.

Sorry to get specific about everything, but i've already been told everything that would fix it at the root and i plan on doing those things, i just want my ride time while the riding is good, and i only want comments on the plugs, or other plugs to safely try.

thanks ahead for any helpful information

 

[EXPERIMENTAL]

wow 120+ views and no replies......this must really be a stumper

 

[SUPERTUNE]

OK,
NO!
The plugs won't make much of a difference.
If you want a major improvement, get rid of the Riva Powerbombs and use a set of retail 44's or 46's that have a better low speed jet signaling.
Race gas compression ratio, MSD-TL or ATP programmable ignition, a properly setup impeller with a matching nozzle are all things that are needed to get those carbs to work better (not make them perfect though) as they are more of a race carb because without a venturi to keep the low jet signal high, you'll need a huge low jet for hit without a bog, then while trying to do normal freeriding they will load up.

 

[showmepro1200]

Thanks Chuck -

Since Jake (Experimental) couldn't be at the lake this past holiday weekend because of work, I took the opportunity to get his RN into the water to once again see how it ran (last time out it was ok, but not great). I started out from the dock, all seemed well until it just bogged down and wouldn't respond, and died. I got it back to the ramp and had to choke the carbs (piece of wood over the mouths, held open slightly) to get it to finally unload and start up. Once started I was able to get it to idle but it bogged and died every time I tried to hit the throttle. After 30 mnutes to an hour of trying to get this thing to cooperate, I pulled my RN out and went and rode.

I too am a believer that this carb type is just too much for a rec boat. I think (Jake can chime in here) we'd like to either go a single big carb or dual carb of smaller size so the riding can go on without all the tuning efforts.

 

[EXPERIMENTAL]

thanks again chuck, i'm defiantly going to change to single carb and rejet. i have a MSD enhancer, but no TL. I don't think my pump is the problem because i have a 12-17 setback SS prop, with a 12-vein 144mm mag pump and stubby cone.

 

[SUPERTUNE]

thanks again chuck, i'm defiantly going to change to single carb and rejet. i have a MSD enhancer, but no TL. I don't think my pump is the problem because i have a 12-17 setback SS prop, with a 12-vein 144mm mag pump and stubby cone.

How big is the nozzle?
When you say setback ss prop are you talking about the prop being setback or the mag pump is a setback pump?
It does sound like your not even close with it running right as it should run better than described.

 

[showmepro1200]

He means a cutback prop.

We've gotta be thinking about other options on the carbs on this machine, as we've been told several times that they may be just too much for the setup we've got here. Chuck, do you think its worth trying a single carb/intake setup (using one of the carbies we've already got in hand)? What would you recommend in intake/adapter/jetting/needle&seat ?

 

[SUPERTUNE]

Just go to a set of 44' or 46's, like i stated before...even with one carb you still have the bad Riva design carb.
Very possible that your engine setup won't like that setback prop! You need a very well planned engine combination to work. The mag pump will load the pump even more than a stock pump, so so the impeller is even more critical to being the correct pitch and spacing.
What's the engine setup? How big is the nozzle? Even the best carbs out there won't work well if you get the pump load wrong.

 

[EXPERIMENTAL]

Hey chuck< if you had some suggestions on what Intake/Single carb/jetting to go with if i were to go with a single carb 44/46/48/49mm what would be your input. Im not sure what to do right now and hearing some suggestions from an expert in this field would be nice

 

[SUPERTUNE]

IF you went to a single carb setup, depending on the engine size and setup, a stock 46 SBN or a 49mm AVL-R Full spectrum on a ATP single intake manifold works the best if using a single for me.
The problem is the single is harder to get dialed in, even takes me awhile sometimes.
A dual 44 / 46 system is really the way to go, this system will support you for a long time with many engine upgrades with just jetting for each engine, I can even use them on our XS1000cc pump gas engine.

 

[showmepro1200]

IF you went to a single carb setup, depending on the engine size and setup, a stock 46 SBN or a 49mm AVL-R Full spectrum on a ATP single intake manifold works the best if using a single for me.
The problem is the single is harder to get dialed in, even takes me awhile sometimes.
A dual 44 / 46 system is really the way to go, this system will support you for a long time with many engine upgrades with just jetting for each engine, I can even use them on our XS1000cc pump gas engine.

I'm curious - why would the single be harder to tune? I would have thought the opposite....

 

[SUPERTUNE]

I think it also has to do with the way my engines are built and setup, they like a lot of fuel and sometimes that can make it harder to get right.
61X downdraft cases don't seem to have the hard tuning problems for a single carb as the 62T cases with a conversion manifold, so in most of the time you are led to believe that it's easy to tune a single.
Put it this way, I have used 160 low jets in a single carb just to get it to work well on just a 735cc engine!
I have also had to use 195 main jet on a 862cc!