Husaberg 660

I've been working on this project for some time now and am finally at the point where I feel it's time to start a thread to document the build.

My history with Husabergs dates back to...well...before there were Husabergs. I was a Husqvarna guy in the 80's. My first was an '83 CR 250. Then I had an '83 CR 500, but the standout Husky for me was the '87 TC510 that I bought used in 1988. I was hooked right away.

In 1996 my brother bought a 1995 Husaberg FE501. I was amazed at how much better that bike was than the old 510. The hook sank in even deeper.

I've accumulated a few other Husabergs over the years culminating in a 2008 FE550 I bought for the specific purpose of racing the 2011 Vegas to Reno desert race. The bike was so exceptional everywhere that we ended up getting 8th overall. Sadly, I was forced to sell that bike to fund the refurbishment of the bathroom in my old house.

Ever since then I've intended to build the ultimate Husaberg for myself. I wanted to start with something cheap because I was going to basically rebuild everything on the bike so, no sense breaking the bank right off the bat.

I found a 1996 FC600 that I ended up purchasing for $400. I've posted about this bike plenty in other threads but, to recap, it had fallen out of the previous owner's truck and tumbled down the highway so it was thoroughly beat.

Here's after spending a ton of time getting it at least worthy of a photo.



Added a Keihin FCR41MX from a 2008 KTM 450SXF.



Swapped to 2013 KTM closed chamber forks and front brake with an Excel A60 laced to a KTM hub.



Added an Eric's Machine aux tank I found on Ebay for a song and rigged up a pair of mounts for the stock fender flap.



Plumbed it to the stock tank via a quick disconnect and an inline valve.



Then I installed Taffy's graphics and seat cover and here's where she's at today.



In addition to the cosmetic damage it had when I saved her, the engine was locked up. Since I was in the process of building my http://husaberg.org/mechanical/16703-husaberg-ktm-hybrid-engine.html I decided that here was my recipient for the engine.

I have a second FC600 engine that I bought off of a guy in Boise who planned to install it in a go-kart but lost enthusiasm for the project (presumably when he discovered how difficult it would be to start with no electric boot). I always intended to do something crazy with this engine so...Here it comes!

Stock 1996 600cc piston on the right at 95mm. Stock 550 piston from Wossner (P/N 8551DA) at 100mm. Combine that with the stock 84mm stroke found in the 600's and you get 659.73cc.



Cylinder bored and sleeved by Thumper Racing. The sleeve is cast iron. Not sure why Travis went that route over aluminum but...whatever.



Cases bored to fit the sleeve.



You'll notice a bluish-grey coating most of the moving parts within this engine. That's the Microblue. Read about it here: Home Of MicroBlue Racing

Here's the rebuildable Carrillo measuring the stock 130mm center-to-center.



The rod pin showing a clearer example of the Microblue application in the center with the outers masked off where the crank webs get pressed on.



KTM 560 SMR head gasket for the 100mm bore.



Microblue supplies their own line of bearings that are already treated. I went with the ceramic balls with steel races wherever possible.



I also had Microblue treat the cam follower bearing races and needles as well as the rod bearing (seen in the previous photo).



I have a titanium piston pin for this engine but apparently no pictures of it. It was a pin that Travis had for a KTM RFS engine but apparently never got used. To make matters worse (or "better" in my opinion because it indicates that progress is being made) I shipped the whole thing back to Thumper Racing earlier this week for final assembly and there will be no further opportunities for photos of internal engine components.

I decided to leave the final machining and assembly work to the experts. I've built a few engines but the sheer number that they deal with on a daily basis makes them far more experienced and I want to give this engine the best chance at longevity possible.

But here's the best part. A phone conversation with Travis on Wednesday had me giddy in a work meeting I attended just after. My co-workers must think I'm a nut. Anyway, Thumper Racing will install the new rod, balance the rotating assembly, assemble the bottom end, Machine the valve pockets for 38mm inlets and 33mm exhausts, port the head to make use of those big valves, machine the combustion chamber for 13.5:1 compression (since I'm committed to using race gas exclusively in this engine), and then final assemble everything from the cases inwards as well as the top end.

Since I like a more responsive engine at the potential cost of occasional stalling, I asked Travis if he would concentrate on weight removal from the heavy end of the crank when balancing. The added benefit here being that a lighter crank is, presumably, easier on main bearings.

Future work will involve boring the carb but I'm going to hold off on that so I can afford to buy Christmas gifts. No sense getting THAT LOOK from the wife when there's nothing for our little one under the ol' X-mas tree.

Stay tuned for updates...

EDE,
I've been keeping a spreadsheet on all the costs of the project and the Superfinish/Microblue part of it was $220.

Unlike a coating such as DLC which makes a surface harder and more slippery so less damage is done when surface contact happens, Microblue attempts to avoid the surface contact from happening at all. It's "hydrophyllic" to oil ("oilphyllic"?). From what I understand, it tends to hold oil in the treated area. How it does this is completely beyond me. To be honest, I'm treating this as a big, expensive experiment because, if Microblue performs as advertised, then my engine should not see the typical early Husaberg failures (cam follower bearings and rod bearings in my experience) that have been so common. When I mentioned to Craig (the owner of Microblue) that this engine has no oil pump and is splash lubricated only, he was "very unconcerned".

Indicentally, I also had the rod bearings, main bearings, pistons, wristpins, and piston rings for my Cummins 5.9L turbo diesel treated with Microblue as well. It's at about a 10 percent increase in fuel efficiency so far. It's not completely broken in yet so I'm hoping to see further improvements. It's difficult to say if this improvement is due to the Microblue, however, because I am also running a different camshaft which is advertised to increase fuel economy as well. At least there have been no detrimental effects so far.

As far as specifics of the coating, I wouldn't expect Craig to give you all of the details but maybe it's worth a call at least. He's a nice guy and very knowledgeable.

Update alert!
I received a call from Travis about a week ago (and chose not to update this thread until just now out of sheer laziness). He has been extremely busy and, to make matters worse, his chief machinist has given notice that he's moving on. His workload makes a lot of sense as, even on little ol' Husaberg.org, I see a lot of guys sending business off to Thumper Racing. That's not to say that there's no progress. I originally asked him to balance the crank by means of weight removal only and it sounds as though he's accomplished that...and then some. Travis mentioned that he was able to remove 12 oz (340 grams) from the crank and that should be a noticeable improvement to the responsiveness of the engine.

I was thrilled to hear this news.

Next on the list of to-do's for this engine are assemble the cases, machine the head for larger valves, massage the combustion chamber for 13.5:1 compression ratio, port the intake and exhaust runners, and probably plenty of things that I've left out.

As mentioned before, I've decided to hold off on machining out the carb venturi for financial reasons. Looking to early spring for this to happen.

So there's the update on the Husaberg 660 project.

Yeah, if it seems like things are going slow, this is why. They're absolutely swamped.

Another update:
Piston - Apparently I did a poor job of measuring parts when I took the engine apart. Once assembled on the rod, the piston I selected was 2mm below the deck according to Travis. We've switched to using a KTM 560 SMR piston from Wossner. Having it sent out for Microblue.

Custom rod - Upon fitup, Travis discovered that the rod was contacting the cases. He had to do some trenching.

Carb - I got a Christmas bonus at work so I've decided to pull the trigger on boring the carb out.

Cam sprocket - We decided to switch to the steel cam sprocket that Bushie supplied the part number for in my hybrid engine thread.

Progress - As it stands right now, the bottom end is together, the head work is complete, the carb work is complete and all Travis is waiting for is the cam sprocket to arrive and the piston to come back from Microblue.

Jetting - Travis's website mentions that the carb overbore comes with custom jetting so I'm hoping this'll get me in the ballpark. I do feel that it's necessary to mention, as an indication of how cool Travis and the folks at Thumper Racing are, that he offered to weld up a sensor bung on my exhaust and provide a wideband to help get it dialed in so long as I decide to do the break-in near his shop. And, since his shop is near some of the best motorcycling in Nevada, I think that I'll take him up on it.

Pictures to come once I get the engine back.

I just received an email from Travis saying that the engine's done. We're going to talk on Monday to square up the finances. That gives me the weekend to find a buyer for my spare kidney as I expect this to be expensive.

I can't even imagine what a Husaberg 700 must be like.
Sitting at home recovering from a cold and keeping an eye on my vomiting 6-year-old. It's killing me that I can't work on the bike. At least the old engine is out.

Working on replacing the swingarm bearings before getting the 660 in place.

A few pics (with the old and dirty not quite out yet...but I assure you that it is now).

By the way, can anyone give me some advice on the procedure to adjust a manual cam chain tensioner? Travis installed one (presumably from an RFS engine) and I imagine it'll need some fussing in the not so distant future.

Well...the engine is in now. There's been a bunch of drama with a wet stator conversion that Thumper Racing urged me to do and both exhaust header bolt holes ended up getting stripped out when I went to torque everything up.

I did some of the heat cycles recommed by TR in the few hours that I had available last week and I can report great results. With the weight reduction from balancing the crank, the engine has definitely gotten more responsive. It didn't really lose any part throttle bottom end or mid range despite the larger valves and head porting. I can't talk to the top end and full throttle yet as I'm trying to adhere myself to the TR break-in recommendations that advise working your way up to 100% pace (full throttle riding) slowly in 10 minute sessions with 30 minute cool-downs in between. I was hoping to get there while riding at the Hangtown motocross track on Sunday but she up and quit!!!!

I was coming into a choppy right-hander with lots of braking bumps and the engine suddenly lost power. It didn't lock up and exhibited plenty of compression when trying to restart it so I'm doubtful anything went wrong inside the engine. My guess is fuel or ignition. Going to tear her apart tomorrow and check my stator connections as the spade connectors I used on the wire ends left a lot to be desired. Hoping that one of them has come loose. The other thing I'm going to check is the needle in the carb. I've had the needle clip come off in a Keihin FCR before which resulted in the needle dropping down into the needle jet. She would give me a "thump" every now and then while kicking so, whatever the cause is, it's potentially intermittent.

Wish me luck.

I looked into it a bit more today and everything seems to be in order. I pulled the spark plug and the jetting appears to be a smidgen on the rich side of spot on if the plug color is to be believed. What I'm really happy about is that I don't see any aluminum stuck to the plug. That's a relief!

The needle clip is still in position so no problem there.

It's at this point that I ran out of time and had to go to work where I'll probably spend all evening distracted by thoughts of what else could have gone wrong.

The sad part is that I have too many projects and won't be able to get back to this one until Sunday.

I promise, when this is all sorted out, I'll post a video of it running. In the meantime, Here's a video from last summer. Same bike but with the old paintshaker FC600 engine that I just removed.

https://photos.smugmug.com/photos/i-rvQBd5f/0/258ff802/1280/i-rvQBd5f-1280.mp4

Hmm...what have we here?! The woodruff key for the flywheel isn't supposed to be 2-piece!



That would explain why I was getting spark only once in a while.