Ok so my bike is a '92 1200. I would like to know what the expected rpm's are when full choke is used starting the bike from cold .
In other words, if the warm engine idle speed is 1100rpms what do you guys get when you start the bike cold and have the choke on fully.
Been a long day for me so I might not be explaining my question very well.
Usually somewhere around 2300.
Harvy
My '92 starts cold with the choke on and idles at 1200, then after about 20 seconds or so, depending on the ambient temp. as the engine warms up the revs rise to 2300 as Harvy mentioned.
It's important to note, even after the on choke idle races to 2300, the oil temperature is no where near it's proper operating temp.
It takes several minutes for that to happen.
Quote from: Pat Conlon on December 02, 2014, 03:55:45 PM
My '92 starts cold with the choke on and idles at 1200, then after about 20 seconds or so, depending on the ambient temp. as the engine warms up the revs rise to 2300 as Harvy mentioned.
It's important to note, even after the on choke idle races to 2300, the oil temperature is no where near it's proper operating temp.
It takes several minutes for that to happen.
Hmm, I have not started my bike for about 4 weeks until this morning I noticed that when using choke on start up from cold the rpms went straight to about 2400 rpms.
Before that when starting when cold with choke on the rpms would be about 1400. It never had the usually rise in rpms when warming with choke on. By that I mean it never had the expected surge of rpm's with choke on you describe as racing.
Vacuum leak maybe?
Your choke system is working properly , no need to change anything .
In the past you may have had a partial restriction in the choke circuit but now it is ok.
It can be common for the revs to go up to 4k at full choke and you push the knob in slowly to achieve around 2k while the engine warms up.
MarkO
What you're describing sounds fairly normal.
My '92 starts on full choke at about 1200rpm. I stand there for a few moments, waiting for it to race up to 2500-3000ish. When it does that, I push in the choke to re-establish it at 1200rpm or so, (I'm not about to stand there and let her rev like that cold). I usually then have time to suit up before the revs start climbing again as she warms. (BTW, completely stock except for #40 pilots; she hated starting cold, (read: wouldn't), when it was in the 30's on the stock pilots.) HTH.
:bye:
Quote from: Pat Conlon on December 02, 2014, 03:55:45 PM
It's important to note, even after the on choke idle races to 2300, the oil temperature is no where near it's proper operating temp.
It takes several minutes for that to happen.
:dash2: Oil takes a long time to get up to it's operating temp. If you consider the time it takes you car to reach coolant operating temp, treble it for oil. I won't thrash my bike from a cold start until I have done at least 15 to 20 kms, depending on conditions. This varies from engine to engine but is a good rule of thumb.
The bike specific habit, that I've never understood (no one does it in their car) of letting it sit there idling for a period of time has no benefit and it you want to spit hairs, has a down side, it is no good for your engine.
The best thing you can do is start it and ride it off while being kind to the engine until the oil is hot, which is way longer than most people think. Any mechanic or owner with a temp gauge will verify this.
This will also get the oil hot quicker.
Noel
My stock '89 will rev up to about 3K RPM with the choke on.
My FJ is probably my coldest blooded bike. It takes a while for it to warm up & accept throttle input without gagging & dying. Of course it is my largest bike & my only 4-cylinder.
Good luck.
what you are experienceing is typical. We have a number of FJs (in fact we are overstocked) and they all are pretty similar. I would not say they are cold blooded; it is important that the carbs be clean, and for starting the enrichener (ie choke) circuit be clean. A "warm up" is not really required for normal riding (keeping RPMs below 5000) in my opinion. Get your gear on, choke it, start it, and ride away. After about 100 yards you should be able to push the choke off and ride.....
Just my experience,
Jeff
Changing your pilot jets to #40 really helps the cold start issue. I almost don't need the choke to start from cold. With the standard pilots, she needed the choke for more than a few minutes. I had to relearn how start my FJ when I put the 40's in.
Thanks for all the replies fellas.
Quote from: FJmonkey on December 03, 2014, 09:18:01 AMChanging your pilot jets to #40 really helps the cold start issue. I almost don't need the choke to start from cold. With the standard pilots, she needed the choke for more than a few minutes. I had to relearn how start my FJ when I put the 40's in.
That is most likely what is needed. My bike is all stock to the best of my knowledge, with the exception of a K&N filter from the P/O. I know that most bikes were jetted lean to meet USA import standards.
What is usually the best jetting for a stock '89 at slightly above sea level?
How involved is the job?
Thank you.
Quote from: ribbert on December 03, 2014, 07:19:33 AM
Quote from: Pat Conlon on December 02, 2014, 03:55:45 PM
It's important to note, even after the on choke idle races to 2300, the oil temperature is no where near it's proper operating temp.
It takes several minutes for that to happen.
:dash2: Oil takes a long time to get up to it's operating temp. If you consider the time it takes you car to reach coolant operating temp, treble it for oil. I won't thrash my bike from a cold start until I have done at least 15 to 20 kms, depending on conditions. This varies from engine to engine but is a good rule of thumb.
The bike specific habit, that I've never understood (no one does it in their car) of letting it sit there idling for a period of time has no benefit and it you want to spit hairs, has a down side, it is no good for your engine.
The best thing you can do is start it and ride it off while being kind to the engine until the oil is hot, which is way longer than most people think. Any mechanic or owner with a temp gauge will verify this.
This will also get the oil hot quicker.
Noel
***Noel, I agree 1,000%*** My comment about oil temp. should not be construed to mean that you let your bike idle to raise the oil temp.
Never do that. Never.
You will cook your exhaust valves. Our air cooled engines need air. After the choke start up procedure, start riding, get air moving across the cylinder fins.
However, ride gently, let the oil get to temp. before visiting the kookaloo zone.
I have a theory: I believe that the majority of the FJ engine's ring/bearing wear comes from early aggressive riding before the oil comes up to op.temp.
Reason: I have seen street bike FJ engines with only 60k miles on them, showing low compression, needing rings/or reseating the valves....and I have seen FJ engines with well over 100k miles with stock compression numbers, and wondered why?
I think it could be the oil temp issue.
Quote from: ~JM~ on December 03, 2014, 11:08:53 AM
What is usually the best jetting for a stock '89 at slightly above sea level?
How involved is the job?
Thank you.
#40 pilots will be a good size. Regarding how much effort, that depends on whether your K&N filters are the pod type or you still have your air box. If the air box is already gone then you are in good shape. I highly recommend getting or modifying a screwdriver to remove and install jets. Here is my pilot tool.
(http://fjowners.com/gallery/7/104_03_12_14_12_33_57_0.jpeg)
You want the blade to be a snug fit in the jet, and a close fit inside the cavity, the jets are soft.
(http://fjowners.com/gallery/7/104_03_12_14_12_34_01_1.jpeg)
Drain the carbs, take the carbs off, turn carbs over. Either buy a JIS Phillips bit or get the RPM SST fastener kit. A regular Phillips bit does not fit properly and the OEM screws seem really soft. A small impact driver was needed to get some screws loose for me. Remove the bowls, remove the old pilots, install the new ones then put it all back together.
If you will be ordering anything from RPM like the jets, consider the UNI dual air filter pods. K&Ns breath really well, but let more dust past the filter and into your engine. The UNIs are reusable as well.
Thanks for the reply. The K&N is a cartridge type in the original air box. I'm not a fan of K&N filters & usually run UNI filters.
I have some hollow ground gunsmithing screwdrivers that fit jets well, along with the JIS drivers.
Great clarity from Noel and Pat on riding "warm-up". I have a BMW M5 with a 5 litre V10. On this car the redline is quite low at cold temps and actually moves up until the oil temp gets to operating range. The operating redline (when warm) is 8250 RPM. As Noel points out this take about 10 KMS of easy driving.....then if you push the M (which I think stands for more Money) button you can unleash it. Kookaloo with a V10 here we come....
Jeff
Quote from: ~JM~ on December 03, 2014, 02:04:52 PM
Thanks for the reply. The K&N is a cartridge type in the original air box. I'm not a fan of K&N filters & usually run UNI filters.
I have some hollow ground gunsmithing screwdrivers that fit jets well, along with the JIS drivers.
Sounds like you are handy with tools.
To get the air box off you will need to remove the upper bolts that hold the rear subframe on and pivot it down and away from the air box. Then you can wrassle it out, its up to you if you want it back in. I enjoy the extra room and ease of access with the UNI pods.
Good on-ya for having the JIS screwdrivers, --BUT-- spend the $20-22 on the SS screw set. The OEM screws are shit! And will strip, even with the right tools. The SS screws will not and you forever will not have to worry about having the JIS set as parts of your road toolkit. Also, if you have the ethanol infested fuel in your area, I'd order 2 sets of pilots so you can always have a fresh set ready to drop in --when-- (not IF) they plug.
My 2ยข, as an early adopter of #40 pilots.
Ed
Thanks for the tips.
I'm fortunate to have 1 filling station nearby that sells "Clear Premium" that is ethanol free. I usually add some fuel stabilizer & a dash of 2-stroke oil on fill up. I try to keep the tank topped off before storing. It bothers me that I do not have manual control or access to the fuel petcock. I like to close the petcock & run my bike until the bowls run dry. Can't do that with my FJ.
If your FJ has a fuel pump a toggle switch in the wire to the pump would do the trick ...
Good deal on the "real" fuel. Here in Kalifornia we used to only get the euthanized (ethanized?) fuel in the winter, until "the powers that be" decided that we really need it all year round. So, one has to be careful to keep Startron or a similar product in the tank, lest the spare jet rule be invoked. Kinda tragic when you actually get pretty good at a jet swap.
Quote from: simi_ed on December 03, 2014, 03:55:39 PM
If your FJ has a fuel pump a toggle switch in the wire to the pump would do the trick ...
I would think that the pump has a electrical connector. Can't you just disconnect it, so the pump won't run?
I only have gravity-fed FJs. I have no knowledge of the fuel pump types.
Quote from: FJ1100mjk on December 03, 2014, 05:56:22 PM
Quote from: simi_ed on December 03, 2014, 03:55:39 PM
If your FJ has a fuel pump a toggle switch in the wire to the pump would do the trick ...
I would think that the pump has a electrical connector. Can't you just disconnect it, so the pump won't run?
I only have gravity-fed FJs. I have no knowledge of the fuel pump types.
84/87 petcocks are easy, unplug the vacuum line to drain the carbs... No Vac, no fuel from the tank...
Quote from: simi_ed on December 03, 2014, 03:55:39 PMIf your FJ has a fuel pump a toggle switch in the wire to the pump would do the trick...
I hadn't even thought about that. Good idea!
Other than hearing the pump kick on when I start the bike, I forget that it's there.
Thanks.
Quote from: ~JM~ on December 03, 2014, 03:26:48 PM
It bothers me that I do not have manual control or access to the fuel petcock. I like to close the petcock & run my bike until the bowls run dry. Can't do that with my FJ.
If you've got a fuel pump you should have a petcock you can turn off, otherwise how would you change fuel filters without fuel going everywhere. On my 93 you lift the back of the tank up and with a 8mm open end spanner turn the little square fitting on the petcock 45deg to turn off.
Quote from: Bones on December 04, 2014, 01:23:23 AM
Quote from: ~JM~ on December 03, 2014, 03:26:48 PM
It bothers me that I do not have manual control or access to the fuel petcock. I like to close the petcock & run my bike until the bowls run dry. Can't do that with my FJ.
If you've got a fuel pump you should have a petcock you can turn off, otherwise how would you change fuel filters without fuel going everywhere. On my 93 you lift the back of the tank up and with a 8mm open end spanner turn the little square fitting on the petcock 45deg to turn off.
I'm aware of the petcocks location. I don't really want to pull the tank after every ride.
[/quote]
I'm aware of the petcocks location. I don't really want to pull the tank after every ride.
[/quote]
I put a second petcock valve in the fuel line so all I have to do is take the seat off. No need to remove tank.
Now that's a good idea. Thanks.
Quote from: ~JM~ on December 03, 2014, 03:26:48 PM
Thanks for the tips.
....... I like to close the petcock & run my bike until the bowls run dry. Can't do that with my FJ.
Why and how?
Do you judge how far from home and shut off the fuel then splutter into the drive or leave an already hot motor idling, getting even hotter and leaner until it dies one cylinder at a time?
Mostly, I'm curious why you do this.
IMO dried out carbs get scale, shrinking gaskets, hardened seals and sticking needles.
Noel
I usually close the petcock on whatever bike that I'm riding about a block away from home. Usually I sputter into the driveway, or it will run out shortly thereafter. Prevents varnish & crap from plugging the internal carb circuits. I've done this for years & haven't had to clean out a carb since then. This is especially important if your fuel has ethanol in it. Ethanol attacks aluminum.
Here are a couple of links that will help you to find ethanol free fuel in your neighborhood.
http://www.buyrealgas.com (http://www.buyrealgas.com)
http://pure-gas.org (http://pure-gas.org)
John (JM) you know that your procedure still leaves ~1/2" gas in the fuel bowl? The fuel level just drops below the pilot/main jets when the engine sputters.
Your procedure does get some separation between the fuel and jets but, the choke circuit pickup at the bowl bottom is still subject to clogging.
The only way to completely dry the bowls out is to use the drain screws at the bottom of the body of the bowl.
Yes, nasty green crap grows in stored ethanol laced fuel.
Cheers