Various '87 Issues

[ajacstern]

Hey guys, hope everyone is doing well and staying safe. I got my '87 rescue FJ running and driving pretty decent and have been putting miles on due to quarantine and the summer weather. I think I have added 1000-1500 in the past month. I still have a few issues I haven't been able to work out though.

I switched the stock brake master cylinder for a 14mm FJR one and kept the same calipers, I can get better braking force but it takes a fair bit of travel before I get much resistance. New brake fluid, new stainless lines, no air in the system. I suppose that is just how it is with this hydraulic match-up. I can't really get as much bite as I want for two finger braking though. It is fine for four finger but my preference is two finger for holding on and using the throttle. Besides doing index finger curls is there anything I can do with the 87 forks to improve bite? It doesn't seem like there are any good alternative caliper options but I have been looking at semi-sintered and sintered brake pads. Do these improve bite or is it just a wear thing? I am worried about them eating up the rotors, not sure if anyone has experience there.

I have this odd issue when coming to a stop with the clutch in or in neutral where the bike just randomly dies. It idles fine, but if you grab the brakes fast when not in gear(enough to make the front dip) the bike just dies. It is really bad when cold (first 20 minutes of running) but still happens occasionally when warm. I don't know what the culprit is. I wonder if it is carb bowl height but I have triple checked the floats and they are all in spec. Maybe oil drag? I am running 15w-40. The carburation isn't quite perfect I think. I have this really bad flatspot in the midrange low 4k to high 5k rpm. I have messed with the carb needles a bunch and haven't found much luck in resolving it. The mixture screws don't seem to do much as well when turned all the way in or all the way out. I am currently running 40 pilot 115 main fourth clip on the needle with stock exhaust and k&n intakes. Is this just a characteristic of the motor? I would think something so torquey wouldn't have much problem in the midrange. Low end pulls pretty well and the top end is crazy.

I also have an oil leak that I cannot find. I have stripped everything around the motor to try and find it, it doesn't seem like it is coming from a gasket or sealing surface. It mostly leaks out of the left-hand sprocket cover side but it comes from higher up. The alternator and starter were wet, replaced the orings on both of them and there is still oil coming from up there.



The head and cylinder are all dry so not sure what else there is to leak up there. There is a small hairline crack near the rear motor mount but that feels dry and shouldn't be able to leak anyway, is it a safety issue I should tig weld though?

There is also a leak on the back side of the motor that also seems to come from nowhere. It drips down in front of the rear tire which is a problem. All I can see on the back of the motor there is a bolt.

Cheers, stay safe yall.

[ribbert]

I got my '87 rescue FJ running and driving pretty decent and have been putting miles on due to quarantine and the summer weather......I still have a few issues I haven't been able to work out though.

Glad you've got it on the road. You have brought your problems to the right place, there will be an avalanche of advice on all your queries, so Ill kick it off with my 2 cents worth.

The FJR master cylinder has an adjustable lever, do you have it adjusted so the take up point is the max distance from the bars? (if that's your preference)

Admittedly, your calipers will remain a limiting factor to some extent but don't underestimate the difference good pads make. The difference can be your brakes feeling like blocks of wood or scaring you with how grippy they are.









IMO, talk of pads eating up rotors is 99.9% urban myth that somehow survives on various forums and FB pages and, like so much other misinformation on the net, is passed on by someone who knew someone who's ........it's never first hand. The forum has a ton of experience with pads, rotor, caliper and m/c combinations.

As for the bike dying under brakes, you say it is irregular and that fuel levels are spec. If you determine beyond doubt that it's not fuel related (more info like how long and from what speed under brakes are you talking) bikes have something that is peculiar to them (as opposed to cars), wiring that can be affected by suspension travel, steering (turning the bars) electrical stuttering on acceleration (yes, I've had that) wind and vibration. Trouble shooting these problems over the net gets murky.

Similarly, chasing oil leaks when you've already eliminated the common and the obvious is difficult over the net, but plenty will chip in and someone will nail it. My suggestion was going to be check the crankcase breather (is it connected to the filter box) but perhaps the amount of oil you describe is too much for that.

If there's one subject here on the forum that has an abundance of experts, and *one guy who wrote the book, it's carbies, they will have the symptoms you describe sorted in a jiffy.

Good luck getting your problems sorted, you've come to the right place.

Noel


* Haha, before too many folk line up to take a bow, that would be David Raforth

[FJ Flyer]

For the brakes, you're kind of stuck with the stock calipers.  Best mod I did was changing the fork sliders to a pair from an '89 and putting R1 calipers and master on with a 17" front wheel.

For the leaks, check the valve cover grommets.  They get brittle and can leak a lot.  Bit of a stretch to get down that low.  Might try cleaning everything up and using baby powder to identify the source.

Good luck.

chris

[red]

Ajacstern,

Unless you have a pump, bleeding brakes (especially the front) will be an anti-gravity proposition.  They now make a banjo bolt with a brake bleeder in it.  These things cost US$15~20 from the right folks, but the wrong sellers may charge you FAR more for them.  Use one at each front master cylinder, brake and clutch.

For the oil leaks, get the area as clean as possible, then spray there with aerosol body powder.  The oil will stain the white powder on the metal before the oil goes everywhere, to show you the source of the leak(s).

Keep es posted.
.

[RPM - Robert]

If that is indeed a crack it will definitely leak from there, depending how far down it goes. Monkey Mark's bike had a crack in a similar location if I recall correctly and I have seen a few in the race cars that crack there and leak oil out.

That crack will only get worse as well as it is at the motor mount and there is some chassis flex which will just exacerbate the crack.

[ajacstern]

I do have the FJR lever on the farthest setting but it takes a lot of squeeze to be able to do anything. Hmm that is interesting if sintered pads do not produce significantly more rotor wear I might go for those then, have you tested them with the stock fj rotors? These rotors feel incredibly soft to me and they are surprisingly expensive to replace. I was looking at the semi-sintered EBC pads (FA88V), they are for cruisers and heavy streetbikes but no mention of friction coefficient. It'd be nice if manufacturers would publish dyno runs of their pads for comparison lol. An electrical problem is a good proposition, I haven't checked the ignition system anymore thoroughly than putting the sparkplug against the head and looking for blue spark.

I have looked into the upgraded forks mod and it is definitely something I am interested in. Haven't found any 88+ fork lowers for sale and the complete forks fetch a pretty penny on eBay. Would be cheaper to just buy modern USD forks and modify the triple tree to accept it I think. The stock fork springs I have are awfully weak even on max preload, I can bottom out the front by looking at it too hard so I have to add in spring replacement with a new set of forks aswell. I have heard some people argue the 16" front wheel gives easier turning but I am not sure how that works as the 17" uses a thinner tire for the same overall diameter. I did the valve grommets + cover a bit ago during a valve job and it is all dry up there fortunately/unfortunately.

I have a syringe I use for vacuum bleeding that works pretty well. I saw those speed bleeders and they did look nice but I don't mess with brakes often enough to justify changing out all the bleeder valves on my bikes IMO (Well the fj is the only one with hydraulic brakes but still). I can reverse/pressure bleed with it too but I find vaccuum bleeding works the best. I checked with the front wheel off the ground and it does start engaging at a decent point on the lever travel but it is so light I can still walk the bike with the brakes pulled to that point. I tried the talcum powder but went I stripped the bike down to check again everything was oiled up so I couldn't tell where it was coming from. Might try it again and just run the bike on the stand without air filters on it so I can see the problem area.

Hmm if the crack is deep enough then that definitely sounds a likely culprit. I am surprised it is hollow in there it looks like just a thin structural piece, I assumed it was filled in. I suppose I should probably drop the motor and buy a tig welder and learn how to use it / find someone who does $$$ OR I could clean it and put on $5 of JB weld and pretend to forget about it. Obviously welding is the best practice but I am not sure if it matters enough that jb weld wouldn't work. It's worked on clutch covers before for sure. Save some money for the forks, brakes, paint, 500HP nitro+supercharger build, etc.   

Thanks for all the advice!

[RPM - Robert]

That particular spot is not hollow it is a support web but the crack usually does not stop there.

You need to figure out why it is broken. Mark's frame was bent, this is also true of the race cars that have problems breaking motor mounts. The additional load from the frame being bent puts stress in directions the mounts were not meant to and cracks things.

You can add some heat directly to the crack and watch it open up. Direct torch heat, we use a small propane torch when chasing cracks.

[RPM - Robert]

Kind of difficult to see in these photos but to the right side of where you circled is hollow. The photos here are the underside directly below the motor mount bolt. You can kind of gauge how much deeper it is compared to the starter hole opening.

Basically from the top of the web and behind it is hollow all the way down. The thin webbing is not hollow.

[ajacstern]

Ah-ha, I see thank you. I couldn't visually see the crack going further but I will recheck. Little worried about using a torch with oil and being so close to the carbs, might have to drop the motor for that. The PO said they laid it down into some grass at around 120 so I wouldn't be super surprised if there was frame damage. I have visually checked the whole frame and found no cracks or abnormal bends; I am not really sure how else to check a frame. None of the shops in my area have a frame alignment machine. The rear tire is offset from the subframe/fender but I am hoping that is just subframe damage. The bike tracks reasonably straight, it goes a bit to the right with no hands on it but I think that is just because I haven't aligned the rear tire properly after greasing the swingarm, it wasn't doing this previously. I hope the crack just formed from jarring impact force and not a permanently bent frame, but if it did would grinding it open with a dremel and filling in with jb weld work as a repair? It sounds like it is not supposed to be stressed in this direction anyway.

[RPM - Robert]

I don't think the JB weld will work. I know we ground out and welded Monkey Mark's bike and it was leaking by the time he got back home.

http://www.fjowners.com/index.php?topic=12995.0

See reply 13

First step is first you need to confirm if that is the leak or not.

[red]

ajacstern,

As for any frame damage, chances are that the engine is holding the frame straighter than it really is, now.  In other words, if you took out all of the engine mounting bolts, I would expect that the frame is bent or warped enough that some of the engine mounting bolts would be difficult or impossible to install again.  If the frame/chassis is now bent, and the engine mounts are cracking because of that, then it is likely that the bike is beyond reasonable economic repair. Another (maybe newer?) FJ may be cheaper than repairing what you have now.  If you can find the exact same year FJ to buy, and you have the storage space, you will have a *complete* set of spare parts for the next bike.

Hate to think that, but it may become a case of cutting your losses.  Now I'm no expert, but I think you need an expert "hands-on" evaluation of the problems.
.

[ribbert]

I do have the FJR lever on the farthest setting but it takes a lot of squeeze to be able to do anything. Hmm that is interesting if sintered pads do not produce significantly more rotor wear I might go for those then, have you tested them with the stock fj rotors? These rotors feel incredibly soft to me and they are surprisingly expensive to replace. I was looking at the semi-sintered EBC pads (FA88V), they are for cruisers and heavy streetbikes but no mention of friction coefficient. It'd be nice if manufacturers would publish dyno runs of their pads for comparison lol.

Hmmm, perhaps if the piston in the single caliper has a slightly larger area than total of the two pistons in the twin caliper the master was designed for, it has to move a whisker more fluid? I'm sure it's been done but I can't recall anyone having the combination you have. Usually the FJR m/c is fitted to the later twin piston FJ or blue spot calipers from other models.

The EBC HH pads are the most popular choice here and many other places, so much so, RPM sell them. They are still I believe, the grippiest pads on the market. I would imagine there are literally 100's of bikes on the forum running them on OEM rotors, as I did for years, they do not eat rotors! The rotors by the way are not that expensive to replace. There is a favoured after market brand that is very popular here and elsewhere for a fraction of the cost of genuine replacements. Once again, these are in widespread use and have had everything imaginable thrown at them in terms of use and abuse over 100's of 1000's of miles and many riders.

There are charts on the net showing the very performance characteristics you describe for brake pads, and more. EBC for example has just such a chart to enable you to make the best choice. However, why waste you own money, learn from the experience of others. If you buy the wrong pads, it's going to be a long time before your replace them again, if ever.

[FJ Flyer]

Good point on the fork springs.  I had also upgraded those, as well.  The advantage with the 17" front wheel is that it opens up a large number of radial tire options.  Once you go radial, you'll never go back to bias. 

[Millietant]

As long as you have a radial on the rear too.

[RPM - Robert]

88HH is the most aggressive
88V is in between a HH and regular organic
88 is standard organic.

All the EBC pads are as above

We like the feel of the HH up front and standards in the rear. We do have a couple customers that run the HH up front and either an HH or V in the rear because they like to do a bit more aggressive trail braking.

It is all about finding what you like and are more comfortable with. That being said HH will last longer as they are a metallic material and have a bit more aggressive initial bite.