Various '87 Issues

[Motofun]

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.

Question for you Randy...What does "HH or V in the rear" have to do with trail braking?
Trail braking is a front brake technique where you ease off the brake lever as you enter into a turn.  It keeps the front tire planted for better traction. 
Here's a hint, when learning how to use trail braking a "softer" compound can help as it is less grabby.  Of course it also has less bite so it will likely take more stopping distance all other things being equal.

[racerrad8]

Question for you Randy...What does "HH or V in the rear" have to do with trail braking?

Having the more aggressive brake pad in the rear, for me at least, limits my modulation while trail braking. The rear tire is more prone to lose traction with the road surface and the back steps out much easier. I don't have any experience with the V compound, but those that use it find it a nice balance between the HH and organic pads. It offers better stopping power over the organic, but doesn't make the rear brake like an on/off switch like the HH.

I will be trying a set on the rear the next time I replace the brakes.

I really like the HH for the front because the FJ is heavy and the brakes have a nice bite which I can then modulate back as I continue to the apex. They allow me to slow down more if I get into a corner too deep whereas, like you mentioned the organics just can't stop as well and cannot offer the additional stopping power if needed.

The addition of the monoblock calipers and their stagger piston designs also help on trail braking riding technique.

Randy - RPM

[RPM - Robert]

Sorry, Moto I should have typed, "They like the more aggressive rear bite whilst trail braking.", not "more aggressive trail braking." I was trying to multi task and the language in my mind didn't translate to the interweb as it came through my fingers.

Some people use the rear brake on entry & mid corner and some don't hardly use the rear brake at all (same goes for normal or panic braking). That is a different debate, and everyone has their preference. I'm not a riding coach and I don't presume to be one so i'm not getting into that debate.

[Motofun]

Got it.  At the very pointy end of the stick many racers use the rear brake to help settle the suspension though when at maximum braking it's of little use in my opinion.  Now heavy weight bikes like cruisers it can be a different story.  For myself I only use the rear brake if I exit the track onto the grass, then it's the only brake you want to use (unless you're going to hit the wall, then it's throw out every anchor you have).

[ajacstern]

Haha if I was going for the most economic option I would have cut my losses before I began, I guess I am just a glutton for bad decisions and expensive projects . After covering the crack in baby powder and going for a ride it seems that the leak is coming from the crack. Not that the crack has expanded further than the webbing but it is actually leaking out of the supposed to be filled webbing. I assume it is cracked all the way through and is leaking on the front and back side. (The picture of the backside of the engine is from before I ran the engine so the powder still appears white, the oil is leaking right into that area)



But as far as this crack being caused by a bent frame I am not convinced yet. I removed the upper rear mount rod near the crack and it was easy to slide in and out, didn't seem out of alignment at all. I would think if the frame is bent that the rod wouldn't slide easily, unless the other engine mounts are holding the frame straight. Is it possible to remove all the engine mounts and support the engine from beneath without removing the engine + exhaust and carbs? Basically leave it place but just supported by a jack on the bottom. If the frame really isn't bent then I will sand down the paint and epoxy over the crack until a vaccine or such and I can get a job again to hire a welder.

Personally I use the rear a lot, probably because of dirt bike experience. The FJ one is pretty touchy though, easy to slide. I might even stick with the organic in the rear it doesn't need anymore bite. Will have to see how touchy the front gets with HH pads and try to match the rear in terms of sensitivity. As long as the rear wheel is still on the ground you can gain more stopping power by using the rear brake imo. It is tricky to use because you reduce pressure on the rear as the front compresses while increasing pressure on the front so it takes some getting used to but I find I can brake about 20% later using the rear on the street. Have yet to go to a street track though so take my advice with a large pile of salt.

As far as the carbies go I have tried moving the needle around in half steps and have yet to be able to figure out this midrange bog. I tried using different needle settings on each of the cylinders until the sparkplug all looked right but that did not work very well so I am going to try and keep all the needles at the same position now. I have gone from 3-4.5 with all of them the same and it still bogs pretty hard and hesitates/stumbles right at 4k. I can't really notice any difference in changing the needle height so not sure which way to go. I assume if it was a gas flow issue then that would affect the top end not the midrange.

[RPM - Robert]

It could be hollow on the 1100/1200. I only had a 1250 case to take a photo of. No 1200s open at the moment.

You can Put a jack and a piece of wood under the engine to support it while removing the engine bolts. Will make it a whole lot easier with two people. One to balance and one to install/remove the bolts.

Even if the frame is not bent when it was wrecked, the jarring from the accident could have stressed it enough to crack it.

This is not a common occurrence in the bikes.

[red]

Ajacstern,

As you remove bolts, you can replace them with thin bolts (or 3/16"~3mm steel rod).  Once all of the bolts are out, it will be obvious if the  frame is bent, when you start re-installing those bolts.  Even if that process works well, however, you will still have a cracked engine mounting lug, and an oil leak.

I know of no repair process for a cracked engine case, that will survive one hard ride.  The problem with welding aluminum is that the metal around the repair is weakened by the welding job, so even when the weld holds, the metal around the welding may fail.  Wish I had better news there, but feel free to pursue your work.  Personally, I might go looking for a replacement engine, at a minimum, if not a new bike.  The RPM guys may be able to help with finding the spare engine, or a maybe a buyer for what you have, to reduce your losses for another engine.

Best wishes.

[fj1289]

If the case is bad - but the frame checks out OK — I'd look for a set of cases and simply rebuild it as you swap the parts into the "new" cases.  Decide if you want to stay stock or add some performance.  Do some of the "preventative" things while you are in there like getting the trans undercut.  Then enjoy the results for decades to come...

[FJ_Hooligan]

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?

<snip>

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.

Way back before I made the "upgrade" to monoblocks, I was running a set of Ferodo HH sintered pads in the stock 2-piston calipers of my '85.  That setup was really good, the brakes were amazing.  So much so that I was somewhat disappointed with the monoblocks, even running HH pads.  I felt the new braking performance was not as aggressive as what I had replaced.

I measured the caliper pistons and you do in fact lose some piston area with the monoblocks.  they make up for it with more swept pad area acting further from the center (so more level arm for the braking force).  The 4 pistons also distribute the braking force over the pad more uniformly.

At one point, I bought the wrong pads.  For some reason I bought a set of EBC "green" pads, I think they were organic, but they were cheap.  Used them for about 2 weeks.  Every time I got back home from a ride, the whole front of the bike was covered with black brake dust.  And I don't ride hard enough to abuse the brakes.  Still have those pads in a drawer somewhere.

[ajacstern]

Okay, after some wrestling I got the motor "out". It is dropped down but still in the frame because I can't get the bike high enough to move it out. I should still have enough working space though. Was able to get a good look at the crack. It isn't too big but definitely leaking. Unsure what I should do to prevent it spreading before putting metal epoxy over it. Because of the angle I can't grind it with a dremel. . Cheers!

[ajacstern]

Ended up grinding a light channel in the crack with a Dremel tool and filling it in with JB weld, will report on results.

[ribbert]

Ended up grinding a light channel in the crack with a Dremel tool and filling it in with JB weld, will report on results.

Risky business offering an opinion on this, but here's my 2 cents worth anyway. The success of JB weld or similar depends on whether you're simply filling the crack or trying to hold it together. The former will work if stress is no longer present, that is, if it was the result of a one off event such as an accident, plenty of engines getting around with glued up holes and cracks. However, if the stress is still there, it will continue to spread, the glue won't hold it together. There is a technique called "stop drilling" which the aviation guys will be familiar with but I've only ever used it or seen it used with success on sheet metal stress cracks.

When you separated the engine from the frame, was there any obvious "relief" as you withdrew the bolts and did you need to knock any of them out?

I don't see why this can't be successfully welded but it's one of those jobs that needs a proper welder. I'm a reasonable welder which means I'm good enough for most jobs and good enough to know my limitations and recognise when I need a great welder! If you want to see just what can be welded on engines, check out Alan Millyard and his amazing engines on YouTube. If you are mechanically inclined, how he makes these machines will have your head spinning.

For the welder, this is not a big job, getting it to him, well, that's another matter, these engines are heavy bastards.

If this was my bike, this is the path I would take and I would be guided by the welders opinion. If you've sought or paid for his expertise, it's no time to second guess him, if he says it's stuffed, start looking around for another engine, not another welder.

If the worst comes to the worst, a dog of an FJ isn't worth much and the engines are bullet proof for 100's of 1000's of kms, hunt around for a pranged or neglected one. Most FJ's seem to be low mileage despite their age, high mileage bikes being the exception.

Some years back I fitted a motor I had acquired for what I thought would be for just a few weeks while I fixed a failed base gasket ( I had a trip to arranged) on the bike's original engine. It had 145k on it when I put it in and it's condition was largely unknown to me. It ran so well that to this day, I haven't got around to re installing my original, low mileage, Wiseco big bore engine. That entire bike cost $500 (with the engine removed in preparation for the output shaft seal to be replaced !!!!) The owner was of the opinion the cases needed to be split and thought he would save some money by removing the engine himself and delivering it to his mechanic. I don't keep records but I reckon that must a at least 100k ago and it still runs like a dream at 265k

A bit of trivia for the old timers here. When I went to buy that bike, the seller was bad mouthing a fellow forum member who had already committed to buy it on ebay weeks earlier and but never followed through. The seller was not happy as he had hung on to it for some time, waiting until such time as it became obvious the sale wasn't going to happen, the "buyer" was Irishluck!
The motor was, and still is, remarkable and it was a complete rideable bike (once an engine was installed) I reckon I must be the only guy here who can look back on him with such fondness. I wouldn't have even known about the sale if not for him raising it on the forum as I wasn't looking for a bike or an engine at that point. As fate would have it, it was on a couple of kms from my house.

For those that don't know or remember Irishluck, he was in the US somewhere and the bike was in Southern Australia! He was a "colourful" former member, a quote from whom Klavdy still uses in his signature.

Noel

[krusty]

You beat me to it with the "stop drilling" practise. I've seen this done by windscreen repairers to stop a crack from 'growing'. Resin is then injected. It's not always successful but could sometimes save on an expensive windscreen replacement.
Perhaps a good TIG welder may be the way to go. My son once holed a piston in his CBR250RR which was successfully TIGged with the head removed (as the cylinders are integral with the cases).

[RPM - Robert]

I few posts with the same or very similar crack...

http://www.fjowners.com/index.php?topic=12794.0
http://www.fjowners.com/index.php?topic=1562.msg16082#msg16082

I am pretty confident Mark's broke before he got home and I don't recall the success of SkyFive

[ajacstern]

I agree Ribbert, I do not expect JB weld to hold at all if it is placed under stress. Once I broke the engine mounts free from rust they all slid in and out easily and I saw no weird frame tweaks. I am hopeful that the engine is not normally stressed that way and it is just the 100ish mph crash of the previous owner that caused the crack. If it doesn't hold I am only out $2 of JB weld and a few hours of quaran-time.  Or at least I hope that is all that is all I am out... I was trying to reinstall the engine but because the oil pan is at a weird angle I couldn't get the engine mounts to lineup. Tried to shim jack-engine surface and the engine slipped off. Oops. I grabbed it and tried to slow it down so it didn't hit to hard but it did hit. Hopefully the oil pan isn't ruined. I also now have the issue of getting the engine back into the frame, I can't lift it like dirtbike engines and have no engine hoist. Anyone have any methods they like to use for installing? I don't think pulling off the suspension would work because of the angle. Might try to clean the oil and invite someone over and see if we can lift it.

If this doesn't work I like the idea of a tig welder because I have a had good luck with welding for really extreme loads before but RPM-Robert points out that hasn't worked well in the past. Replacing the cases would be a bit more certain to have no problems and would "give" me an opportunity to do the bottom end, undercut the trans, replace the shift forks, etc. Bore it 1600cc while I am at it .