Author Topic: Project - Pre 75 XL250  (Read 31838 times)

0 Members and 1 Guest are viewing this topic.

Offline Slakewell

  • Legend
  • *****
  • Posts: 3577
  • Slakewell Motordrome
    • View Profile
Re: Project - Pre 75 XL250
« Reply #75 on: November 07, 2010, 03:05:34 pm »
Do the 77 250 fork internals fit the 72 250 forks? is that what you did or are you talking 350 stuff?

Yes you can if you want just undo the bottom nut and slide the chrome legs and internals inside the 72 bottom's 
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle

Offline MX?

  • Legend
  • *****
  • Posts: 609
    • View Profile
    • Classic Bike Forum
Re: Project - Pre 75 XL250
« Reply #76 on: November 07, 2010, 03:47:14 pm »
Greentree bike looks great!
In the middle of home reno's at present, so still clearing up the new shed so I can tackle the engine work without falling over junk. ::)
Missed our last 2 meetings for the same reason......
More time and more bike next year. ;D
That '77 fork sounds like an idea?

Offline LWC82PE

  • Superstar
  • ******
  • Posts: 6006
    • View Profile
    • PE motorcycles & SuzukiTS.com
Re: Project - Pre 75 XL250
« Reply #77 on: November 07, 2010, 04:32:00 pm »
Now that i think about it, i dont think i would do that fork mod. I dont think its in the spirit of pre 75 as the 77 forks were not out then.
Wanted - 1978 TS185 frame or frame&motor. Frame # TS1852-24007 up to TS1852-39022

Offline bazza

  • Legend
  • *****
  • Posts: 2353
    • View Profile
Re: Project - Pre 75 XL250
« Reply #78 on: November 07, 2010, 06:49:25 pm »
greentrees xl that i think
 Ed has now was a rocket. xr200 electronic ignition? I run Honda points only and have had no problem since 1991 whan i built the 305, first set of  replica points gave trouble.From memory XL350 swing arm is 1" longer and helps.
Once you go black  you will never go back - allblacks
Maico - B44 -1976 CR250- 66 Mustang YZF450,RM250
Embrace patina

Offline Slakewell

  • Legend
  • *****
  • Posts: 3577
  • Slakewell Motordrome
    • View Profile
Re: Project - Pre 75 XL250
« Reply #79 on: November 08, 2010, 08:02:30 pm »
Now that i think about it, i dont think i would do that fork mod. I dont think its in the spirit of pre 75 as the 77 forks were not out then.

You can if your anal enough pull both sets apart and just copy the 77 ones , Honda didnt make new ones just modified the old ones to give more travel.
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle

Offline LWC82PE

  • Superstar
  • ******
  • Posts: 6006
    • View Profile
    • PE motorcycles & SuzukiTS.com
Re: Project - Pre 75 XL250
« Reply #80 on: November 08, 2010, 08:43:07 pm »
so how did they increase the travel? Longer damping rods?
Wanted - 1978 TS185 frame or frame&motor. Frame # TS1852-24007 up to TS1852-39022

Offline MX?

  • Legend
  • *****
  • Posts: 609
    • View Profile
    • Classic Bike Forum
Re: Project - Pre 75 XL250
« Reply #81 on: January 06, 2011, 09:18:22 pm »
OK, no turning back now!
Going to fit the new 305 piston and roller cam gear.


Normally I'd be paying someone to do the bigger engine work..but how hard can 1 cylinder be?? Should have been learning this years ago.  :-[
Have a few dumb questions though:
How can you tell when a cam chain is stuffed? thought someone told me sideways movement once?

As far as I can tell these guides look fine as well?

As far as lubing the cam / cylinder etc. on assembly do I just use a little engine oil? or is there a better product?
What's the best gasket sealant to use?
Thinking of making up some kind of valve spring compressor, unless anyone can recommend an off the shelf one?
Any tips on degreeing the cam.....or anything else for that matter ::)


Offline matcho mick

  • Legend
  • *****
  • Posts: 2279
    • View Profile
    • Moto Tumbi
Re: Project - Pre 75 XL250
« Reply #82 on: January 06, 2011, 10:32:28 pm »
cam chains stuffed when you run out of adjustment  ;D,(replace for peace of mind  ;)),just assemble with the engine oil your'e going to use,either sprayon coppercoat (repco) head,n basegasket,all other alloy to alloy surfaces use 3 bond silver, sparingly,works for me, :P
work,the curse of the racing class!!
if a hammer dosn't fix it,you have a electrical problem!!

Offline MX?

  • Legend
  • *****
  • Posts: 609
    • View Profile
    • Classic Bike Forum
Re: Project - Pre 75 XL250
« Reply #83 on: March 04, 2011, 07:10:49 pm »
Thanks Mick (belated  :))
OK 'nother problem,
Being the dummy I am....can someone have a look at this


Now can someone confirm:
  • I've made a mark for TDC
  • At TDC I set clearances to zero
  • The intake valve will open 0.04" from fully closed at a point 18deg before my TDC mark is reached
Am I correct so far?
If so, when the intake begins to close (or whatever) at 45deg after BDC. should this also be after it has closed 0.04"?? :-\

Offline matcho mick

  • Legend
  • *****
  • Posts: 2279
    • View Profile
    • Moto Tumbi
work,the curse of the racing class!!
if a hammer dosn't fix it,you have a electrical problem!!

Offline MX?

  • Legend
  • *****
  • Posts: 609
    • View Profile
    • Classic Bike Forum
Re: Project - Pre 75 XL250
« Reply #85 on: March 31, 2011, 06:19:28 pm »
Finally back on track but for other brain related problem....
Seems I can't read a degree wheel, even after reading that article  :-[

These pics are with the valve opening to 1.016mm (0.04") and the reading on the degree wheel which started with the engine TDC on the  TDC wheel mark and traveled counter clockwise to be almost back at that point again




Now this shot is after having continued to roll the engine over until the dial gauge hits the exact same point just before the valve is fully closed.

 

Sooooo.....what I want to know is what / how to take off those two readings on the wheel??? In the top one does it read 16deg, 344deg or neither
If I've got it right I'm meant to subtract the second reading from the first then /2 and +90 to come up with a lobe center of 103deg

Offline shelpi

  • Legend
  • *****
  • Posts: 2056
    • View Profile
Re: Project - Pre 75 XL250
« Reply #86 on: April 13, 2011, 12:26:50 pm »
THE BEST REAR SHOCKS, BEST VALUE, GAZI,  ;) IT WAS ONLY 6 MONTHS AGO AND HAD NEVER HEARD OF GAZI, BEING A SCEPTICAL OLD BUZARD ASKED LOTS OF QUESTIONS THEN WAS CONFRONTED WITH TAKE THE PLUNGE AND BOUGHT A PAIR OF GAZI VMX HYPER FOR ME RM125B WOW,CAN IT GET ANY BETTER THAN THIS? CHECK EM OUT SEE WHAT YOU THINK.
HAS ANYONE ELSE HAD THE PLEASURE OF GAZI? PLEASE LET ME KNOW ;D

Offline Freakshow

  • Superstar
  • ******
  • Posts: 7277
  • Adelaide, SA - looking for a "YZA" tank
    • View Profile
Re: Project - Pre 75 XL250
« Reply #87 on: April 13, 2011, 12:45:10 pm »
thats a bit random ?
74 Yamaha YZ's - 75 Yamaha YZ's
74 Yamaha  flattracker's
70  Jawa 2 valve speedway's

For sale -  PRE 75 Yamaha MX stuff, frame, motors and parts also some YAM DT1,2,A and Suzi TS bikes and stuff

Offline shelpi

  • Legend
  • *****
  • Posts: 2056
    • View Profile
Re: Project - Pre 75 XL250
« Reply #88 on: April 13, 2011, 12:50:05 pm »
SORRY IT WAS FROM THE FIRST QUESTION,  :-\ WHAT SHOULD I SPEND MY MONEY ON?

Offline Slakewell

  • Legend
  • *****
  • Posts: 3577
  • Slakewell Motordrome
    • View Profile
Re: Project - Pre 75 XL250
« Reply #89 on: April 13, 2011, 03:21:37 pm »
THE BEST REAR SHOCKS, BEST VALUE, GAZI,  ;) IT WAS ONLY 6 MONTHS AGO AND HAD NEVER HEARD OF GAZI, BEING A SCEPTICAL OLD BUZARD ASKED LOTS OF QUESTIONS THEN WAS CONFRONTED WITH TAKE THE PLUNGE AND BOUGHT A PAIR OF GAZI VMX HYPER FOR ME RM125B WOW,CAN IT GET ANY BETTER THAN THIS? CHECK EM OUT SEE WHAT YOU THINK.
HAS ANYONE ELSE HAD THE PLEASURE OF GAZI? PLEASE LET ME KNOW ;D

All my bikes have Gazzi I love them
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle