had a quick search and found some info but not really what I want
I have a 92 FJ1200 with the T/Ace rear end and for the last few years have been running 18/39 with a 530 chain.
My motor even though rebuilt (with cam timing and ignition timing mods) has a vibration (not real bad but annoying after a few hours) that starts at 3,200 rpm and finished about 3,700 rpm which, with the above gearing is right on our Australian highway speed limit of 110 kph. Once I hit 4,000 rpm the motor is so smooth you hardly know its running. The gearing is also a bit gutless down low.
I was thinking about 17/40 to raise the rpm to hopefully over the vibey bit and to give me a better take off from stop.
I modded my FJ as soon as I purchased it so have never ridden a stock FJ so have nothing to compare it to.
Any help much appreciated.
Dave
Dave
I run 18 /40 with the GSXR rear and that puts me on 3800 at 100kph. My bike has no vibes at any rpm.
I have bee thinking of 17/40 to which should pop me up to 4000 at 100..
Cheers..
Dave, is that your FJ on the UK FJ mod site?
Harvy
yes it is, geez that was a long time ago
Quote from: FJSpringy on November 27, 2009, 01:01:10 AM
yes it is, geez that was a long time ago
It sure was.
Actually reading that and other stuff on the mods site not long after I bought my FJ lead me to googling more info, which lead me to the Yahoo group, which in turn morphed to me being here.
So I guess its all your fault..... :good2: :good2: :good2: :good2:
Like, this is a great bunch of mates, most of whom I've never met in person, and I doubt you would find more motorcycle knowledge on many other internet groups (be it FJ or not!).
Are you still one the same FJ?
Cheers
Harvy
Quote from: Harvy on November 27, 2009, 01:25:26 AM
Quote from: FJSpringy on November 27, 2009, 01:01:10 AM
yes it is, geez that was a long time ago
Are you still one the same FJ?
Cheers
Harvy
:good2: yes I am, but it has changed quite a lot since those days, still got the T/Ace rear but lots more mods, my mates still give me heaps about it :lol:
The PM rear wheel I got came with a 46 tooth sprocket. I now run 18/46 which translates to 100km/h@4250 and 120km/h@5000 ... it took some getting used to, but for most real-world riding it's a good fit. In Ontario you get a big legal hit if you go 50km/h over the speed limit. 150km/h on the FJ is easy, so having the revs higher keeps me legal.
There is, evidently, no law against getting up to speed quickly :smile:
...and take a look the FJ Gearing.xls file in the files sections ... it's stored as FJ Gearing.zip
I am a big fan of the gearing commander site. With a little effort you can take a look at nearly any gearing/speed/RPM situation and easily apply it to the real world. Its even able to calculate in both MPH and KPH
http://www.gearingcommander.com/ (http://www.gearingcommander.com/)
Only the 89-93 model is shown, but to my knowledge the primary and transmission gearing has not changed so it should work for all models.
thanks guys, I am going to put a 17 on the front and see how it goes, the chain is in good nick so won't be an issue.
Springy,
You shouldn't be getting vibes all the way up to 4000 rpm. Have you checked the front motor mounts are not seized?
Also check that all the bolts in the frame rail links (under the footplate and up near the front motor mounts) are tight and whole?
Rover,
Where did you get a 40T sprocket for the GSXR wheel? I've not been able to find anything less than 42T.
This gives me gearing that is almost exactly the same as stock, and no vibes once over 3K rpm.
Cheers,
Arnie
Quote from: Arnie on November 27, 2009, 05:55:48 PM
Springy,
You shouldn't be getting vibes all the way up to 4000 rpm. Have you checked the front motor mounts are not seized?
Also check that all the bolts in the frame rail links (under the footplate and up near the front motor mounts) are tight and whole?
Cheers,
Arnie
Thanks Arnie,
I only get mild vibes between 3,200 and 3,700 and it appeared after the addition of the XJR1300 carbies and their tuning on the dyno, we never did get it as good as I would have liked under 4k, once you hit 4k the FJ takes off like a rocket, quite amazing for an old lump.
I agree about the frame rail bolts I checked them a while back the rear ones were loose so I did tighten them up, haven't looked at the motor mounts for years so I will have a fiddle with them later in the week.
Regards,
Dave
I have the 17-180-55 rear tire. I run the 17 and 41 sprocket set up. That puts the RPM's at 110 kph at about 4200. I like the set up and it keeps the bike quick enough to keep it fun. Although, I am thinking of getting another chain and sprocket setup to make the bike accelerated quicker.
Later..... :bye2:
On top of the motor mounts, make sure you have the carbs synced. That can also really help to smooth things out.
'92+ bikes have fully rubber mounted engines if memory serves me. I seem to remember others saying the lower engine mounts on those years also seize up. David R. said it was a PITA to get them out, but once everything is cleaned up and working the way it should, almost all the vibes were gone.
Quote from: pdxfj on November 27, 2009, 10:54:37 PM
'92+ bikes have fully rubber mounted engines if memory serves me. I seem to remember others saying the lower engine mounts on those years also seize up. David R. said it was a PITA to get them out, but once everything is cleaned up and working the way it should, almost all the vibes were gone.
Yup... the difference is dramatic. There are pictures in the gallery section under Misc FJ Photos. And David R. documented the process well. It's worth the effort.
http://www.fjowners.com/index.php?topic=592.msg4349#msg4349 (http://www.fjowners.com/index.php?topic=592.msg4349#msg4349)
http://www.fjowners.com/index.php?topic=594.msg4348;topicseen#msg4348 (http://www.fjowners.com/index.php?topic=594.msg4348;topicseen#msg4348)
Thanks gents I will start planning to renovate the mounts and get this done it sounds exactly like my problem.
btw I had a spare 15 mins this morning so I changed the 18 tooth front sprocket to a new 17 tooth, I went with a genuine Yamaha cush drive one, quite nice :good: the bike is different with the 17 tooth sprocket, don't know yet if it's good different or bad different, certainly picks up quicker.
One thing I did notice is that the old 18th tooth sprocket is hardly worn after 20,600 kilometers guess the Scott Oiler, despite being a right PITA is doing its job.
I have grabbed a bit of inch water pipe and have started building the puller to do the motor mounts, prolly get around to it some time next week :gamer:
Quote from: Bob on November 28, 2009, 10:06:31 AM
Quote from: pdxfj on November 27, 2009, 10:54:37 PM
'92+ bikes have fully rubber mounted engines if memory serves me. I seem to remember others saying the lower engine mounts on those years also seize up. David R. said it was a PITA to get them out, but once everything is cleaned up and working the way it should, almost all the vibes were gone.
Yup... the difference is dramatic. There are pictures in the gallery section under Misc FJ Photos. And David R. documented the process well. It's worth the effort.
http://www.fjowners.com/index.php?topic=592.msg4349#msg4349 (http://www.fjowners.com/index.php?topic=592.msg4349#msg4349)
http://www.fjowners.com
/index.php?topic=594.msg4348;topicseen#msg4348 (http://www.fjowners.com/index.php?topic=594.msg4348;topicseen#msg4348)
(http://i48.photobucket.com/albums/f225/scotw99/P1010651.jpg)
dirty one and clean one, btw kiddies this is not a job for the feint hearted, make sure you have plenty of beer on hand :drinks:
Anyone here running an 18t front, and a 42t rear on a stock FJ swingarm?
What length chain do you get? How many links? :unknown:
Quote from: Firehawk068 on January 17, 2010, 10:18:46 PM
18t front, and a 42t rear on a stock FJ swingarm?
What length chain do you get? How many links? :unknown:
I can tell you that with 17/42, 110 links... it just fits, gotta put the chain on the wheel before inserting the axle, and chain adjustment is very forward. I think 112 links would workout about right..
Quote from: Firehawk068 on January 17, 2010, 10:18:46 PM
Anyone here running an 18t front, and a 42t rear on a stock FJ swingarm?
What length chain do you get? How many links? :unknown:
I'm currently running that exact combination on my '85. Using the standard 110 link chain.
DavidR.
I'm using an 18/42 combination on my '91 with stock swingarm and use a 112 link chain.
Arnie
Quote from: Firehawk068 on January 17, 2010, 10:18:46 PM
Anyone here running an 18t front, and a 42t rear on a stock FJ swingarm?
What length chain do you get? How many links? :unknown:
My 86 runs lovely with 18 up front to give a bit more swingarm clearance and a 46 on the back.
According to the marvelous mechanical gearing calculator (to be found in the files) - 18/44 leaves things pretty close to the 86 standard of 17/41 (1 tooth on the front change equalling 3 on the back) - this was the case or so it felt. Anyway, went for a little lower gearing since we've great roads here near Napa.
I like the difference - quicker, obviously when trying and an added bonus of livening up 5th gear enough, so when you're just wanting to be lazy you can stay in 5th and the engine does the rest. I suppose it's a little more buzzy at interstate speeds, but I try to avoid that kind of riding if possible.
Andy
Oh nearly forgot - my advice.
The guy who works for the 'sprocket center' (google it) was really super helpful and has a chain link calculator. They sell DID heavy duty things - pricey but worth every cent for peace of mind. The sprockets they sell are all steel which is meant to be the way to go - mega strong if a bit heavy. Recommended.
Andy