1986 510 4stroke twin shock project phase #2

I have assumed the engine was in the center, those little through tubes stayed in the same virtual place and the kink of the tube moved the bottom portion of the front frame piece.

Most likely you have engines with the 12 mm swingarm pivot bolt where you have seen denting in the rear inserts from the hard steel piece the bearings ride on which kind of resembles a piston wristpin. If it was me and I didn't choose to make new rear engine inserts I would remove them and weld in the sleeve with some filler rod not of super soft variety and clean up the end in a lathe or some other way before re installing. A piece of copper in the hole will preserve it during this process.

Fran

I run a 86 500TC barrel, piston(90mm) and head on one of my 84TEs, while the whole bottom end is original. As said angle on inlet port flange is different and when I have time by next week I'll photograph and post my simple yet very effective solution which also improves performance, have patience plse. Also the cooling fins on the 86 are quite a bit bigger which here in Africa is an absolute bonus and the setup of choice.

When you swap Singleshock bottom ends into Twinshock frames:
Swingarm bolt on 83-84 twin is 12mm and on single is 14mm and way shorter than the 12mm bolt. Some of the earlier frames are even 10mm bolts which is an absolut no-no with 510 torque.
I machine swingarm bolts from axle steel (old fwd sideshafts) and for the bushes you go to a quad workshop and find yoursef a handfull of good used 20mm gudgeon pins, I think they came off a 400 Suzuki. To bore (almost ream) the gudgeon pins if need be, you put the bush in a lathe and mount a high quality 14mm concrete (yes) drillbit, which comes with tungsten tips and gets the job done for bushes and also the frame, together with Tapmatic. Obviously afterwards you machine the bush to correct length too.

Love that 84TE, handles way better than any of my singleshockers (including a real trick 86TX).
Its stupid fast yes.
In a drag it gives new 300 2Ts a solid hiding (oops), just runs with 450s, and topspeed its adios dudes. Very few mod bikes can actually hurl along at 100mph+ as these comfortably can with a 14/48 sprocket setup.

Good luck, its a worthy project, and if you can get the frame headstock to 28,5 deg, even sweeter for taking the inside and flatout sideways through turns.

Ps, just read the part where you obtained original TE frame, xcellent.
Just ensure the bearing sleeves go the full length through the engine casings, otherwise the righthand one will come loose, relocate towards the centre and you will experience suicidal headshake when decellerating, with damage to bolt and frame.

Very interesting! I am doing ruwfo's project in reverse.. building a 86 using a earlier top end with l/c bottom end, so have the reverse head problem, which i think is less of a headache as the manifold is shorter (no spacer) so look forward to mor info..
I rode a "special" -84 frame with tt 500 motor with cut down,"twin shocked" 86 alloy swingarm and I have to say on tight corners its absolutely out turns my 84 te. the frame was extended 40 mm lower to accomadate the engine and forks were probably a bit softer so extra weight + lower weight+ compressed forks = best turner. Both bikes had the forks about 20mm through the top of the triple clamp. It was nowwhere near as fast though..
So question- what is the head angle on the 84? I know my 81 maico is 28.5 and it out turns the te. I also rode a 84 500 auto and that out turns the te as well..but thats a different beast altogether..

AWESOME thread and build! But I'm a little confused, too. Husky DID make an air cooled 4 stroke dual shock "white bike"... so how come you're having to do so much frame fabrication? Is it because you're not using an original 4-stroke frame? I'm just curious, not criticizing.

I have several 81/82 and 83 two strokes. At first glance, the 83 frame looks like they used the same engine cradle and just tweaked the rear shock geometry for the ITC suspension design. Not so! They moved the engine forward almost an inch, and had to put that "kink" in the downtube and change the front motor mount plates and...

keep the info coming! I would really like to see a test on the 86...

Gents, my bike is filthy, my arm recently fractured, thus I'll describe setting 86 engine up into 83/4 frame.

86 the rubber manifold bolts straight to the head at an angle which is square to the engine stroke for the manifold flange and bolts, giving a very short inlet tract.
83/4 head had an allu spacer between same rubber manifold and head, the angle of this party is not square to the stroke but downward thus dropping the carb lower and much longer tract. This angle for manifold and bolts obviously is machined to the head.

I took one of those 83/4 allu spacers and machined the angle onto it. The topside just clears the cut and bottomside is taken off by 10mm. Then a 4mm flange is made to match footprint of rubber manifold. Perpindicular to flange weld tube of 40mm id and some 35mm in length, the external od close to that of carb as possible. I use a rubber manifold connector, pirated off a R80G/S BMW airhead, to flushmount carb to new manifold.
Lastly your bolts require an angled washer for seating onto new flange, which I hacksawed from copper tubing.
All the above obviously gasketted and airtight.
This setup moves the 40mm DeLlorto carb backwards towards airbox by a whole 20mm above 83/4 and like 2 inches over 85/6 which was a less than blueprinted setup. You need to make a plan to actuate choke which now falls outta fingers reach.
Lengthening inlet manifold and adding 2 megaphones makes it substantially faster and more responsive than 86. Best running motor ive had yet, and xcept for the above its stock 500TC.

The 500/510 became commercially available mid 83. It was pushed into production too quick and had basic gremlins and assembly quality control issues.
Clutch slipped yes but 1mm spring spacers sorted that. The 1st 83s had 36mm squirter Dellorto, no hassles with it at higher altitudes and it ran like a bat outta hell as is. I'll rebuild one of my 83TX's with this setup for historic sake and to prove a point. 40mm Dellortos, minus accellerator pumps, came in 84 already.
The ignitions were an issue to some extent yet that was changed together with crankpin taper for what was the best at the time.
The rael bitch was nobody understood the fact that the kickstarter mechanism was that of a 240cc 2T which was already overstressed in 500 config, nevermind a 4T with substantial valvespring pressures. Its a trick kicking these things to life, especially once hot and flooded, like i recently experienced at the bottom af a ravine during a race.
All the valveguides (bar one super low hour 86 TC) ive come across needed replacement after looootsaa running.
For all the criticism its incredible how poked rings, pistons, valves, valvestems, rods can be and once going these things still smokily run the beejezuz outta all else.

Far as i care, any other 4T motor of the time and up to 6yrs later was a complete and obsolete relic by comparison.
Husky showed clearly that a 4T could run with and away from the bigbore 2Ts and started the resurgence of 4T technology.

With megaphones they still sound better that any other 4T single. Music for pistonheads with go thats still way up there.

Great thread! I'm doing the same project, but my 83 wr frame has been modified. we cut the head stock's gusset to pull the forks in to 27 degrees of rake & 4.5"of trail, then welded in new gusset. Also welded thick washers on swing arm gusset so s/w axle has more bite. Lower frame rails have additional tubing added for strenghtening. My mentor also recommended adding brace across airbox to strenghten upper shock mounts, It will make changing air filter a problem though. We also have a fix for twin leading front shoe, made a new push rod out of aluminum with left & right threads for adjustments, seems the stocker is a push rod that flexes under load. Next project is a mod. to the Ohlin shock gas tube that replaces the internal piston with a KTM bladder. If anyone is interested we can make them available with instruction for a few $. 40mm forks will have Gold Valves.The ignition will be replaced with a modern unit mounted to stock backing plate. We did find a source for the cam chain which is the only hard to find part. The rest of the engine uses water cooled parts that are still available. I'm intersted in any MX 4 speed engines if anyone has one, mine has some bad gears. Long live megaphones!

Hello pvmx510tc
Do you have pics of the transformations ?
Thanks
Michel

What diameter did you make the aluminium push rod?- very interesting. The standard rod has M5 threads and is not particaularly robust, but I would have thought M5 aluminium no good either.
Some photos would be good as Michel said..
Cam chain should be easy to find from any bearing/ chain supplier by the metre (or foot)
My mate here bought a length of it + masterlinks, both using it

Real fun project. I've started having thoughts of a twin shock 4T as well. Great info..........