One of the best thing about the FJ is how easy it is to work on. So after a little discussion on Facebook tonight about fuel economy and jetting, I get to thinking. I have a new set of bigger than standard jets and the bike has always felt a bit sluggish at low rpm and a bit surgy (if that is a word) at higher revs.
So here I am Monday evening, long day at work, dinner is done. And now bike in bits. Lucky I know every bolt on it. Will finish it tomorrow.
From This
(http://fjowners.com/gallery/9/4336_30_09_15_2_33_59_2.jpeg)
To This in 30 mins
(http://fjowners.com/gallery/9/4336_12_10_15_5_05_13_0.jpeg)
Quote from: Urban_Legend on October 12, 2015, 06:17:31 AM
(http://fjowners.com/gallery/9/4336_12_10_15_5_05_13_0.jpeg)
Do you find it helps to filter the cooling air to the head?! :lol: :lol: :lol:
Quote from: fj1289 on October 12, 2015, 10:07:27 AM
Quote from: Urban_Legend on October 12, 2015, 06:17:31 AM
(http://fjowners.com/gallery/9/4336_12_10_15_5_05_13_0.jpeg)
Do you find it helps to filter the cooling air to the head?! :lol: :lol: :lol:
Had to sit them some where, but filtering the air to the head might not be a bad idea. Plenty of bugs in there.
Ok tech question. I have just changed my pilot jets from 40's to 42.5's. So my issue is I went from being lean to really rich. The new pilot are not genuine mikuni, and I have heard the the non genuine items are bigger. So should I spring for genuine mikuni jets or is there a way to lean it out without changing jets again.
No expert here but I would stick with Mikuni jets. I assume you readjusted your fuel/air screws and rebalanced your carbs? From reading your first post I can't determine which problem you are trying to solve. The pilots are most effective 0 to around 1/4 throttle. How are your carbs set up ?
Air Pilot jets......................
Fuel Pilot Jets....................42.5
Needle position................
Main Jet.........................
That info might help another member to help. Nice looking bike by the way :). POD's sure make it a lot easier to do carb work ! Now if the throttle cables had a quick disconnect :).
I have a 1200 with 42.5 fuel pilots, air pilot jets 155, needle in mid position, 117.5 mains, My fuel air screws are out about 2 1/2 turns. I have been getting 46-49 mpg (using GPS for mileage calculations). I am rich on the top end and since have backed down my mains to 112.5's. I would have used 115's but I didn't have any on hand. Haven't had time to run it since the jet change.
George
Hi Movenon. Sorry about the lack of info. My aim was to liven the bike up a bit. It has always seemed doughy at low revs, and with 17/40 sprockets, I am told it should be wheel standing out of corners (which the bike does not). I had forgotten about the needls and you the carbies have been balanced. I was thinking the bike was running lean, so I decided to play with the jets (might be a bad move , but I ave to learn somehow)
Quote from: movenon on October 13, 2015, 07:44:20 AM
No expert here but I would stick with Mikuni jets. I assume you readjusted your fuel/air screws and rebalanced your carbs? From reading your first post I can't determine which problem you are trying to solve. The pilots are most effective 0 to around 1/4 throttle. How are your carbs set up ?
Air Pilot jets...................... 155
Fuel Pilot Jets....................42.5
Needle position................It's in the 3rd (mid) groove
Main Jet......................... 115
Fuel/Air screws are 2.5 turns out
That info might help another member to help. Nice looking bike by the way :). POD's sure make it a lot easier to do carb work ! Now if the throttle cables had a quick disconnect :).
I have a 1200 with 42.5 fuel pilots, air pilot jets 155, needle in mid position, 117.5 mains, My fuel air screws are out about 2 1/2 turns. I have been getting 46-49 mpg (using GPS for mileage calculations). I am rich on the top end and since have backed down my mains to 112.5's. I would have used 115's but I didn't have any on hand. Haven't had time to run it since the jet change.
George
Quote from: Urban_Legend on October 13, 2015, 02:54:34 PM
....I am told it should be wheel standing out of corners (which the bike does not).
Who told you that?
No problem on the information. Your jet numbers look good or at least close enough for a good running FJ. The proper way to work with the jets is to start with the mains and work down. Reading your comment about surging would lead me to believe you are lean in the mains BUT with 115's you should be good.
If it were me:
I would do a plug reading "just because"
Then make sure the floats are in spec, parallel and not binding,
Check for any air leaks associated with the intake manifolds, cracked manifold, O rings etc..
There is some good info down in the files section the carbs and tuning that might be worth a read.
"...I am told it should be wheel standing out of corners (which the bike does not)." Well mine doesn't either :). Might be a bit optimistic for a 100-130 hp bike weighing 580 Lbs plus or minus with stock gearing anyhow. I think of my FJ as more of a train with a little bit more power. Now if you can get 200hp and the weight down to under 400 lb :)... (and if I lost 150 lbs :rofl2:) The above is just an opinion. There are some high hp/TQ FJ's out there that will get your attention. Those members can enlighten you more than me.
Hope some of this helps more than hinders.
George
Gives you an idea of what effects what at what throttle position.
(http://fjowners.com/gallery/7/1651_23_08_14_6_37_20.jpeg)
Thanks for the info George.
Pat it is entirely possible I dreamed it all after inhaling too much petrol fumes while pulling the carbs off.
I might try lowering the needles. The carbs were rebuilt at the start of the year and it got all new seals and o rings and float Heights were good.
When I started the bike last night it only seem to be too rich at lower rpm, but haven't taken it for a ride to confirm. Plenty of black smoke when giving it a rev from idle but cleared when held a 4000 rpm and reved.
that sounds a lot like worn emulsion tubes. Factory pro makes replacements but I am not aware of anyone who has tested them. I believe RPM also markets replacements, which I am sure are well tested.
Quote from: the fan on October 13, 2015, 05:55:27 PM
that sounds a lot like worn emulsion tubes. Factory pro makes replacements but I am not aware of anyone who has tested them. I believe RPM also markets replacements, which I am sure are well tested.
I think emusion tubes were a part of the FP Config10 kit. :scratch_one-s_head:
If so, I have a set in the '89.
Quote from: the fan on October 13, 2015, 05:55:27 PM
that sounds a lot like worn emulsion tubes. Factory pro makes replacements but I am not aware of anyone who has tested them. I believe RPM also markets replacements, which I am sure are well tested.
The emulsion tubes and the diaphragms are the only things I haven't replaced.
Your diaphragms are easy to check Mark, with the air filters off just lift the slides up with your finger and put a another finger over the big elongated hole at the top, if the slide stays there or at the very least creeps down very slowly their ok, it it drops quickly they've got a tear or hole in them.
You say it's doughy down low, but what's it like at high revs, does it pull hard, have you ever done a compression test on it.
The 4 deg ignition advance mod adds a little bit of pep down low, doesn't take long and easy to do.
Quote from: Bones on October 14, 2015, 02:07:43 AM
Your diaphragms are easy to check Mark, with the air filters off just lift the slides up with your finger and put a another finger over the big elongated hole at the top, if the slide stays there or at the very least creeps down very slowly their ok, it it drops quickly they've got a tear or hole in them.
You say it's doughy down low, but what's it like at high revs, does it pull hard, have you ever done a compression test on it.
The 4 deg ignition advance mod adds a little bit of pep down low, doesn't take long and easy to do.
Hi Bones. The diaphragms seem ok, just old, and they have been patch, so new one wouldn't hurt. It pulls hard between 5000 and 7000ish rpm then seems to run out of legs and struggles 9surges up to 9000 (not that I get up there very often).
I have not don't a compression test on it. The motor is as I bought it off Timbo. I have been thinking the it probably needs the valve shims done, but I don't have the gear for that.
I have not done the ignition advance. All these reason are why I would like to get to a shed day, but my contractual (and family) commitments are making that difficult, and I feel I have donated enough money to the local bike shop.
Speaking of contractual commitments, there is a very real chance that I might not be able to get to the FJ Rally now either. Bugger. I was looking forward to it too.
I suppose my next big question is - Are the emulsion tubes and the diaphragms/slides interchangeable between the 1100 and 1200?
The slides are different. The 1200 slide has different cut on the bottom. The 1100 slides I think are flat across the bottom. Beyond that I can't say anything. You might send an e mail to RPM. Randy will know if you can replace all the slide with 1200's. I assume the diameters are the same?
You can change out the diaphragms independently with after market diaphragms. But ask questions before you buy them. I have never seen (other than online) or used any.
George
The slides in my 85 that was built in 84 has curved bottom slides. The slides are original.
Chris
The slides in my early 84 were flat bottom. The emulsion tubes that had a shroud did not work well with my flat bottomed slides. I could not get a good idle.
Contact Randy @ RPM
Thanks. I will flick Randy an email. Probably would hurt if I upgraded my slides anyway. I am pretty sure the original motor for my bike (which the carbs are off) had a lot more than the signposted 50000km. Would be more like 150+km, so everything is/was well worn. Same as I am sure the current motor has more than 35000km stated for it.
If your float level is off you can get the kind of problem you are experiencing..
Also here is a link I use for tuning carbs. http://www.factorypro.com/tech/carbtun.html (http://www.factorypro.com/tech/carbtun.html)
Use the high rpm method.
Hey all
Had another bit of a tinker with the carbies on the bike today. Found out some stuff, not much of it good :cray: . First I changed the needle height. that made a big difference and the bike started first kick, with no choke. This is not usual for my bike. It was also revving high. Hmmmm. Did the thumb test on the diaphragms. Seems like I have 3 buggered ones. SH!T. Bit more investigation I also probably have a vacuum leak too. Can't find it though, as everything seems to be as it should.
Why is it when you drop a screw/bolt/nut it will always find the most inaccessible spot to fall too, and if I did manage to touch it, it falls into an even hard place to get to. Grrrrr
Ok so I decided to have a go as advancing the timing as per directed. Seems like some unmentionable previous owner has stripped out the Philips bit holes. No go there either, not without stuffing up the screws completely and I have no spares.
Next job......the old motor, lets look at that and decide what to do with that. It is alrady in a million pieces. Head is stuffed with burnt out valves, but I already knew that. checking over the case and there next to the counter shaft sprocket. a big crack. Case Stuffed.
So here I sit with my glass of bourbon try to think of the next step. I do know of someone wanting to sell an 88FJ parts bike with two motors for a very reasonable price. the only issue is it is 8 hours drive away. Still making the old 1100 into a 1200 sounds like a reasonable plan at the moment.
More to come.
Mark
So last night after a few relaxing bourbons, I decided onb2 courses of action.
First was to try and fix up my crappy diaphragms and find and fix my vacuum leaks. Today I bought some liquid insulation tape to coat the diaphragms. I also got some rubber grease to coat the ends of all the tubes, block off caps an around the edge of the diaphragms to give a nice wet seal.
The aim of this is to keep the bike rideable over our summer months.
Second it to purchase the 1200 parts bike and make my old 84 1100 into a 1200 hybrid. Who cares about concourse, the bike has so many mods now, what's a few more. Moditis is a serious illness. :crazy:
Quote from: Urban_Legend on October 17, 2015, 10:40:12 PM
So last night after a few relaxing bourbons, I decided onb2 courses of action.
First was to try and fix up my crappy diaphragms and find and fix my vacuum leaks. Today I bought some liquid insulation tape to coat the diaphragms. I also got some rubber grease to coat the ends of all the tubes, block off caps an around the edge of the diaphragms to give a nice wet seal.
The aim of this is to keep the bike rideable over our summer months.
Second it to purchase the 1200 parts bike and make my old 84 1100 into a 1200 hybrid. Who cares about concourse, the bike has so many mods now, what's a few more. Moditis is a serious illness. :crazy:
That's the spirit ...Moditis can be treated with a continual dose of tinkering with your FJ. :wacko2:
I finally got to take the bike for a bit of a run this afternoon. first one since i had the carbies apart. The carbs could do with a balance, but i defiantly picked up a few of the missing horses. It now revs freely thought the rev range, and pulls harder than it ever did from 3000 plus.
I returned the primary jets to 40s and raised the needle to the forth slot. The bike now only requires the choke for initial start up, and not for very long. (2 or 3 minutes)
Just need to find a way to stop the oil light from coming on under acceleration now. I have filled the oil to the top of the sight glass, and still doesn't like a full twist of the throttle. One step at a time.
Every little thing i do is an improvement. :yahoo:
Mark
Hope this works. here is a little vid of the bike in operationhttps://www.youtube.com/watch?v=Pwt4mASacKw (https://www.youtube.com/watch?v=Pwt4mASacKw). (it was warmed before i revved it.)
Mark
Sounds pretty good. :good2:
On the subject of your oil light , from the vid it looks like you have a spin on filter.
Unless the filter has the drain back feature , it will give a false oil level.
Try this, warm bike up to normal idle then shut down and put on center stand . wait 5 min and check your level . top off to the top mark.
Reason is the spin on filters have extra capacity and will empty out into pan when the bike sits and give a false full level , but when started up the oil goes back into the filter and you are now low.
I use the k/n filter from RPM that has an anti-siphon feature to prevent drain back .. started using them because of the oil level problem . There are other filters you can use with the same feature but they were too large for me and I would hit them with my boot when riding.
That being said , I will still get an oil light only on hard white knuckle acceleration or when climbing a steep grade leaned way over .
This is normal and no problem as the oil light is just a level indicator and not pressure.
Maybe you already know all this and I have wasted your time, but maybe someone doesn't and it will help them too. :mail1:
Peace out. :drinks:
Or you might just need a new one of these...Oil Level Sensor (http://rpmracingca.com/proddetail.asp?prod=4H7-85720-01)
Randy - RPM
Quote from: racerrad8 on October 26, 2015, 03:13:40 PM
Or you might just need a new one of these...Oil Level Sensor (http://rpmracingca.com/proddetail.asp?prod=4H7-85720-01)
Randy - RPM
that would be too simple ..gotta make the problem harder than it is. :dash2:
Thanks for the info Mark and Randy.
I do hope it is Randy's solutuon though.
The oil light comes on from spirited acceleration from standing starts (intersections etc. ) and slow corners (right handers are the worst offenders) and also when you hit the kookaloo zone.
The bike does have two small oil leaks that just won't fix and i think it must be burning a bit too, although there is no visible smoke. I has been using about 500ml of oil over 1000km ish.
I am aslo pretty sure it needs the valve shims done too, but i need to get the gaskets and bolt rubbers if i am to do these, and someone with some experience in doing them (who has a shim kit) would help too.
Mark
Quote from: Urban_Legend on October 26, 2015, 04:32:30 PM
Thanks for the info Mark and Randy.
I do hope it is Randy's solutuon though.
The oil light comes on from spirited acceleration from standing starts (intersections etc. ) and slow corners (right handers are the worst offenders) and also when you hit the kookaloo zone.
The bike does have two small oil leaks that just won't fix and i think it must be burning a bit too, although there is no visible smoke. I has been using about 500ml of oil over 1000km ish.
I am aslo pretty sure it needs the valve shims done too, but i need to get the gaskets and bolt rubbers if i am to do these, and someone with some experience in doing them (who has a shim kit) would help too.
Mark
Mark, if you're coming down for Troy's Manshed days next month, I'll take all the necessary tools, shims etc to do your valves. I have quite a few shims in the 2.70 - 2.90 range. You may need some thinner ones so if you could borrow as many as you can, we should be good to go.
Regards, Pete. :drinks:
PS. This also applies to anyone else that may want to check their valve clearances.
Quote from: oldktmdude on October 26, 2015, 04:52:45 PM
Mark, if you're coming down for Troy's Manshed days next month, I'll take all the necessary tools, shims etc to do your valves. I have quite a few shims in the 2.70 - 2.90 range. You may need some thinner ones so if you could borrow as many as you can, we should be good to go.
Regards, Pete. :drinks:
PS. This also applies to anyone else that may want to check their valve clearances.
I hope you are serving brekkie to the blokes, the engine needs to be stone cold for a proper valve adjustment. A roll in freezer might do the trick for same day work. I suppose you could roll in early and aim some hard blowing electric fans at the big lump to get the temp down to ambient.
Unfortunately no I won't be at Troy's men's shed day. I would need to take time off work to attend an my contract won't allow that at the moment. Will be the same for the FJ rally next year if I get the next contract I applied for. However I should be getting 5 weeks off from 4th Dec. So might be able to make a special trip.