Topic: 500 top on 550 bottom

[dave500]

gday,ive got a pretty freshly rebuilt 500,its got 16000 klms on it now,the transmission is a bit clunky as the 500s are,sometimes the gear lever will stick up,untill you release the power then itll flick back down to normal,mostly in 3rd and 4th,im thinking the selector drum is pulling the shifter link into the case and holding it ,i was thinking of shimming the drum on the neutral switch side to fix this,ive tried the best looking drum locators i have,,,that or i have two 550 motors that run ,my fresh top end should go on a 550 bottom end ok,i have the engine bracket with the clutch cable holder,the cable should be longer for the 550 im guessing,has anyone done this?my 500 top end is rebored 1st over with xl125 pistons and the head relieved to suit so im keen to keep it,ive also tried a couple of other gear sets complete with the drum and forks,and it s pretty similar,,the 550 is said to be an "update "to fix the sloppy shifting of the 500,i can see the total difference in the assembly internally,providing i have a good 550 bottom end, is this a worthwhile christmas break activity for me?

[Retro Rocket]

Gday Dave, stick this in the sohc/4 Bikes section mate. Anything related to sohc  honda 4's goes in there..

Cheers

Mick

[Retro Rocket]

oops...looks like it was being moved as i wrote that post....

Mick

[dave500]

thanks steve/retro,,still a bit green ,,i think ive found what to do now,cheers.

[dave500]

on that left pane where your names is?how do i insert my location /age etc?cheers

[Retro Rocket]

Click on your name in any post, then look on the left hand side you will see profile info. Under that you will see "modify Profile", the second heading in that list is "modify profile information" click on that and fill in the details....

Mick

[bryanj]

500 top will fit direct on 550 bottom and clutch cable is supposed to be the same, only the end bracket difference

[Retro Rocket]

Is there any advantage to doing this?

Mick

[dave500]

thanks bryanj,where abouts in england are you? i was born in catford ,london,came to australia in 65,,yeah retro the 550 has a totaly different fork arrangement,and is meant to be a slicker box,mine has its own idyosyncries(or what ever word im trying to write),and if i swap rides with some one i have to tell em to shift slower than you might like and use the clutch,mines a bit more funny with no clutch shifts,ive today dissembled a 550 (i bought those 4 in just bikes 2x 500 +2x550 a fortnight ago)ive seen diagrams of the 550 ,but pulling one down is better,the drum on the 550 rolls in a proper bearing on the clutch side,aswell as two forks are suspended on a separate shaft,not wrapped around the drum as in the 500,the linkage is shorter aswell ,and the detent lock looks more positive on the 550,ill end up just reboring a 550 i can see it now!!

[bryanj]

Me, originaly north of Manchester now in Gloucester.
500 overbore parts are cheaper than 550 overbore parts but you could bore the 500 block to take a set of your 550 pistons if the 550 bores are that rusty(has to be rust or sieze that kills 'em as they never seem to wear).

550 box is not that much better than a good 500 one just updated

[dave500]

thanks bryanj,i was led to believe the 550 was cured of the 500s sticky shifting etc,i understand its the same transmission but with an improved selection assembly,this 550 looks to be factory bore,(i havent cleaned the crowns yet)i dont know whats available in uk compared to here as far as oversize goes,,ive never been one to just re-ring and hone old engines that havent run for ages ,then again i do reuse bearings in their original positions,compression is sought after i guess!,new pistons must be fitted or im never happy,rebores are mandortory if i see any rust pitting in these old bores,ive had my 500 3 years (16000 klm)and was just looking at an improvement over the 500 transmission,so the 500 barrel does bore to the 550 ?i wasnt sure ,thanks for that,hey what car do you drive?

[bryanj]

Me I got a 91 pug 405 estate that I got for nothing 'cos it didnt go and a 2001 mitsubishi L200 2.5 TDI  pickup, or ute as i believe you call 'em that i've had from new.

Main reason for the box change on the500-550 was cheapness of selectors the 500 used most of the 450 twin box and the selectors were expensive to make, when in good order gear change is just as good as any other. Other main change was to do away with clutch pushrod so as to speed the engagement and remove a potential oil leak

[dave500]

oh ok bryanj,ill stick with what im running till it really peeves me,its not real bad i was looking for an improvment,in the mean time ill reassemble the 550 cases ready,its great to get good info here,,im new ,this is a great site!!ive driven the same car for 26 years!!its a holden,1973 hq series premier sedan,308 cubic inch v8 (5 litre) 4 barrel rochester carby,no pollution control(pre 1976),t-bar trimatic 3 speed auto,variable power steering,dual exhausts,this is how it was factory built!,,itll 1/4 mile in 14.6 seconds!it weighs 1480 kilos!ive never cared about fuel costs,,theres plenty of 70s 6 litre cars here aswell,my holden when built had the option of the chevy 350 aswell.

[bryanj]

If you need a manual i can do you the genuine Honda 500 one with all the 550 supplemants on a cd in pdf for cost of postage + a beer

[dave500]

thanks bryanj,i have the same manual i downloaded,as well as a detailed parts list ,have you got that?it makes it better at the parts counter if you give them a number ,their more interested in selling you a new bike than search for old parts!its handy for the lengths the bolts are supposed to be aswell .ive stripped a 550 down now,im going to get the cases blasted etc,and reassemble it as a potential donor,ill do the top end eventually,ill tidy up the head at least during the xmas break,maybe the carbies aswell,polish some bits,funny how one thing leads to another,plan A quickly becomes plan B!!!

[Retro Rocket]

Off Topic, hi Dave, one of our American members is staying at Logan and is looking for someone to ride with .....interested?

http://forums.sohc4.net/index.php?topic=13338.msg681872#new

Mick

[bryanj]

I got the full set of parts books including a No 1 in japanese, thats how i got the part number for the side panel transfer under the badge on K0 500 and all the seperate carb "O" rings