Electric plenum heater experiment (single carb)

[skiri251]

Okay so cheapo grip heater from Hong Kong arrived.

Pathetic looking as expected (?) but attached them to the plenum bottom with aluminum duct tape.

Attached temp probe.

Followed by insulation.

Ambient temp.

10 minutes or so after started applying 13V (manual charger) current is about 1 amp.

So I hooked up everything and try to start the engine.

It seems there is not enough gas going to the cylinders.
If I shoot starting fluid, it starts but dies immediately.

I have plastic fuel filter which is not recommended by Tom. Could this be the cause?

One more suspect is the fuel fitting. It says 1/8" pipe to 1/4" hose adapter but I noticed 1/4" ID hose fits too loose.

Any ideas?

 

[Ansimp]

I think you may have a problem by folding them in half as it may over heat and cook out the resistance strip

 

[skiri251]

Ansimp » Sun Feb 09, 2014 2:31 pm[/url]":3egkj892]
I think you may have a problem by folding them in half as it may over heat and cook out the resistance strip

It's only angled 10 degree or so. Can't imagine overheating because of that.

Anyway I have an issue with fuel delivery right now..

 

[joedrum]

hmmmm on the running ... I don't think its gas feed ... your runner look quite large in ID ... I am assuming there a transition piece on the way the carb is sitting ....

I would take the plug out ... turn kill switch off position and spin motor with starter to fill bowl up colpletely ....then clean up mice and put back in and try again ... it should start .. if it still dyeing ..choke the crap out of it as soon as it starts ....it might try to stay running .. could be leaking air still somewhere ... use that metal tape to seal suspect areas ... just throwing stuff out skirri

 

[dan filipi]

I'm thinkin just not getting enough gas.
Without choke at even 70 degrees I had to twist the throttle quite a bit to pump gas down the throat, 4-5 twists easy before it would fire.
Electric fuel pump is a definate plus here.

 

[sgq700]

I think you have not filled the bowl in the carb for what ever reason, it has nothing to do with your heat! you aren't even close to hot enough to make a difference in the intake. At 80 deg , i still have to gove mine 1 twist of the throttle(to let the choke close) return it to closed(for fast idle)hit the start button and away i go! If you don't have any vac leaks that is.. Before you go too far, fill the carb bowl from the top(no down the intake!!) thru the vent likr where your jets are and see if it will start and run. i am guessing you have not ran the carb yet and it is a very remote chance that the needle and seat are stuck? Try filling the bowl first... Just my opinion. :headscratch:

 

[sgq700]

btw, i run 2 filters, one stock and 1 aftermarket before the carb after the pump.. and 1 more question, do you have your inlet for the fuel in the port that Tom had the blue tape on? I couldn't see in your pic.....

 

[skiri251]

Thanks every one.
It was the fitting.
Went to AutoZone and bought another one and compared the two.
Both boxes say 1/8" pipe to 1/4" hose but the first one's hose side is clearly very thin, 1/8" maybe. Damn O'reilly.

So now the engine starts okay but hard to rev and idles horribly.
I touched the runners and plenum by hand then the coolant pipes from the head and finally got it.
The runners are so cold and coolant pipes are so hot.
No way wimpy grip heaters can heat it. Maybe the coolant heaters are generating hundreds of watts of heat.
So I will go with coolant heater as well.
I took everything apart shortly after the "experiment" and found traces of raw gas everywhere.

 

[skiri251]

joedrum » Sun Feb 09, 2014 2:48 pm[/url]":bnrjktnk]
your runner look quite large in ID ... I am assuming there a transition piece on the way the carb is sitting ....

The runner ID is 1-1/2". Is it too large?

And yes, the transition piece is between carb and plenum.

 

[skiri251]

sgq700 » Sun Feb 09, 2014 4:23 pm[/url]":2a2w2bb3]
btw, i run 2 filters, one stock and 1 aftermarket before the carb after the pump.. and 1 more question, do you have your inlet for the fuel in the port that Tom had the blue tape on? I couldn't see in your pic.....

Yes I hooked up the adapter to the hole covered by the blue tape.

Now, regarding the coolant tapping, did you say you got the hot side from one of the pipes coming from the head?
Where should the cold (return) side be connected?
I read other thread and it says that right after the water pump is the best place but if there are easier to hook up places I want to go there.

Lastly what kind of hardware should I use for the hookup?

 

[sgq700]

From reading here, some folks have"reducers" in the runners, i don't, mine is just like your's except i have heat from the water return lines from the right head to the floor of my intake(boxed in the inverted V) 3/8"npt in and out. not much flow as all i did was drill and tap the thin pipe from the right(pass side) dead, used a 3/8" heater hose and drilled the back of the return to the water pump,again with a 3/8" npt and heater hose. Never checked temp but it run's perfect!! the tubes are cool but not cold at 70deg here. I cannot compare it to stock as i put my bike together from junk and have never ridden a stock jap bike? But i sure do LOVE this one. I would follow the advice of Tom and HOTT with heat to the bottom of the intake. As i said, we have the basic same set up and mine works TITS!! you are a good fab man so no big deal... tear it up :saluteright in the rear of the return manif. where the 2 pipes from the heads connect)

Again, check for vac leaks!!! i used a O ring on each tube at the elbow to the head because the fit was too loose for my liking , i just used a small blunt nose punch and pushed the O ring past the first part of the rubber... Just my opinion, may not be needed but i melted a LOT of pistons with vacume leaks

 

[joedrum]

well the runners night be okay if the icing stops ... I would go ahead and do water chamber heat set up ..just as 700 did and go from there ....it could be you have to choke runners some but its no big deal just do the water thing first ...and lets see how it goes

 

[dan filipi]

I would say this experiment is a bust then.
No worries and don't feel at all bad about it. Each trial tells us more what works and what doesn't as a group effort.
You are the first to try this, I pat you on the back for the effort. :music:

As for the way it's running,
You said when you took it apart there was gas everywhere.
On mine I had a flooding problem at one point.
Turned out some tiny pieces of the emgo filter lodged in the float needle seat preventing it from closing and flooded bad.
That's one possibility but you also need to find where the gas was coming from to get the plenum wet.
If it was coming out of the plenum or runners anywhere there will be air leaks there and you'll never get it running right.
Spray ether (staring fluid) works very good to find air leaks while running. You'll hear a change in the engine.
Just little spurts at the fittings is all that's needed.

 

[skiri251]

dan filipi » Sun Feb 09, 2014 6:25 pm[/url]":3pr6d5mo]
I would say this experiment is a bust then.
No worries and don't feel at all bad about it. Each trial tells us more what works and what doesn't as a group effort.
You are the first to try this, I pat you on the back for the effort. :music:

I anticipated grip heaters were not hot enough so I ordered 5 ohm 50 w capacity resisters from Allied Electronics. @ $4.15 a piece, it comes in aluminum heat sink which I can mount on the plenum bottom. It will produce ~40W but I am thinking heat transfer is not good enough. The temp probe mounted on the back side of grip heater read around 80F while the engine was struggling. Nothing beats a bath of hot water I guess..

dan filipi » Sun Feb 09, 2014 6:25 pm[/url]":3pr6d5mo]
As for the way it's running,
You said when you took it apart there was gas everywhere.
On mine I had a flooding problem at one point.
Turned out some tiny pieces of the emgo filter lodged in the float needle seat preventing it from closing and flooded bad.
That's one possibility but you also need to find where the gas was coming from to get the plenum wet.
If it was coming out of the plenum or runners anywhere there will be air leaks there and you'll never get it running right.
Spray ether (staring fluid) works very good to find air leaks while running. You'll hear a change in the engine.
Just little spurts at the fittings is all that's needed.

I found one brazing fault at the bottom of the plenum. Other gas traces are inside of the factory intakes so maybe they were condensation of the fuel mixture?
I will somehow pressure test the intake before the next try.

 

[skiri251]

sgq700 » Sun Feb 09, 2014 5:25 pm[/url]":2ezrp60j]
From reading here, some folks have"reducers" in the runners, i don't, mine is just like your's except i have heat from the water return lines from the right head to the floor of my intake(boxed in the inverted V) 3/8"npt in and out. not much flow as all i did was drill and tap the thin pipe from the right(pass side) dead, used a 3/8" heater hose and drilled the back of the return to the water pump,again with a 3/8" npt and heater hose. Never checked temp but it run's perfect!! the tubes are cool but not cold at 70deg here. I cannot compare it to stock as i put my bike together from junk and have never ridden a stock jap bike? But i sure do LOVE this one. I would follow the advice of Tom and HOTT with heat to the bottom of the intake. As i said, we have the basic same set up and mine works TITS!! you are a good fab man so no big deal... tear it up :saluteright in the rear of the return manif. where the 2 pipes from the heads connect)

Again, check for vac leaks!!! i used a O ring on each tube at the elbow to the head because the fit was too loose for my liking , i just used a small blunt nose punch and pushed the O ring past the first part of the rubber... Just my opinion, may not be needed but i melted a LOT of pistons with vacume leaks

I am still not sure of the places I should tap in.
Could you post pictures?

I have been seeing drops of water on the floor just under the water pump.
So this mod will be a good opportunity to check/replace it.

 

[dan filipi]

Just to pass on what I've experienced....

The entire intake assembly from the carb base to the heads MUST be completely airtight or all efforts to get it running right will be wasted.

The thin carb base gaskets are trash and will leak.
Pick up some thicker gasket material and cut your own.
When the carb is bolted down, it leaves impressions in the thicker material. A good sign it will seal.

Once you can get a fairly steady idle at around 1000 rpm, your looking good.
By good I mean that the single carb deal is very sensitive to vacuum leaks. Idle is the most affected.

Once you get it running fairly decent, let it warm up til the fan cycles then shut it off for 5 minutes.
While off, the heat transfers to the plenum and warms it up good.
Then start it. I would see an improvement in running every time I cycled it like this which made it overwhelmingly obvious how necessary plenum base heat is.

 

[sgq700]

I would have to take apart my bike to take pic's. The feed for mine is the hot water return pipe, that is the tube between your intake runners where they attach at the head. with the intake off, i drilled a hole for the 3/8" npt tap about 3" before it goes into the water return manif under your intake(the alum piece with your temp gauge sender and your fan switch are) and on the very rear facing flat end of the water manif is where i put the return line. It isn't forcing all the coolant thru but i didn't feel i need that much due to our temp in Phoenix. You will have almost the same as it gets HOT in Torrance. I wish i had taken pic's before i put it together but i didn't expect it to work so well first hit! Hope this helps a bit!!

 

[skiri251]

dan filipi » Sun Feb 09, 2014 8:05 pm[/url]":3hg3zw3q]
Just to pass on what I've experienced....

The entire intake assembly from the carb base to the heads MUST be completely airtight or all efforts to get it running right will be wasted.

The thin carb base gaskets are trash and will leak.
Pick up some thicker gasket material and cut your own.
When the carb is bolted down, it leaves impressions in the thicker material. A good sign it will seal.

Once you can get a fairly steady idle at around 1000 rpm, your looking good.
By good I mean that the single carb deal is very sensitive to vacuum leaks. Idle is the most affected.

Once you get it running fairly decent, let it warm up til the fan cycles then shut it off for 5 minutes.
While off, the heat transfers to the plenum and warms it up good.
Then start it. I would see an improvement in running every time I cycled it like this which made it overwhelmingly obvious how necessary plenum base heat is.

Thanks Dan.
I will follow this.

 

[skiri251]

sgq700 » Sun Feb 09, 2014 8:11 pm[/url]":1ppp5b7n]
I would have to take apart my bike to take pic's. The feed for mine is the hot water return pipe, that is the tube between your intake runners where they attach at the head. with the intake off, i drilled a hole for the 3/8" npt tap about 3" before it goes into the water return manif under your intake(the alum piece with your temp gauge sender and your fan switch are) and on the very rear facing flat end of the water manif is where i put the return line. It isn't forcing all the coolant thru but i didn't feel i need that much due to our temp in Phoenix. You will have almost the same as it gets HOT in Torrance. I wish i had taken pic's before i put it together but i didn't expect it to work so well first hit! Hope this helps a bit!!

Is this what you did?

 

[sgq700]

I forgot something that is Very Important! If you do yours like mine, when you drill and tap the tube and water manif. They are very thin alum ! don't drill any larger than you have to and do not run the tap any more than you need to start the threads of your npt(pipe) fittings. I also sealed my threads with good old hard #1 permatex sealant YES!! Those are the places!!!