| Support us |
Just click the links below and your donations will make a difference here. |
 |
|
|
bob__
|
1# |
Rank:none
Score:0
Posts:396
Registered:
03/28/2004
Time spent:
0 hours
|
(Date Posted:02/17/2005 9:15 PM)
since you've mentioned the higher gears I'm making a possible erroneous assumption that you are not talking about MX use
wind and weight might be your limitations---odd thing to say, I suppose--I 've done a similar transplant--78 XL100 engine in a dinky cafe racer--
tossed out the barrel and two piece head and then put a big bore kit into an SL125 barrel--only work to the head was a valve grind--(the SL barrel will fit in that case with no case machining)-----------had a big time flattening out at 60 or 65 mph--straight pipe was chucked and I built my own header and put on a no name used two stroke silencer and then..............drum roll-----------------a carb from an ATC 185!!!!!!!! the last two items put me at 70 plus mph and I'm around 200 lbs.---friend of mine, maybe 150 lbs took it to 80 plus a tad and that ain't bad for that little bike--
somewhere in the mix I also put a small half fairing on and I figure the only limitations now are from my weight and the remaining wind resistance---the rear sprocket is about 6 teeth smaller and the front is maybe 2 larger---fun bike down hill or in a flat canyon--gets beat up a little going up to the top but you'll play hell staying up with it on the way down---
the whole theory here was that you can only go so fast on a flat, tightly curved road and once you get to that speed it doesn't help to have 1000cc more than I do---
I don't think the XL175 head is similar enough to use---------the above transplant requires using the SL125 cam chain---
--------------------------------------------------------------
ratbikes and bull terriers
http://www.community-2.webtv.net/oldrice/BritifyinganoldHonda/
|
|
generatorshovel
|
2# |
Rank:none
Score:0
Posts:89
Registered:
02/17/2005
Time spent:
0 hours
|
(Date Posted:02/18/2005 11:27 AM)
Thanks for you input Bob , I'm trying the stock carb next , then a later "split" 125 head Bigger valves?)
The bike is intended for salt lake speed trials , but I need to sort the top end out in 3 weeks,,or I have 13 months to get ready for 2006
Cheers  Tiny
--------------------------------------------------------------
It CAN be done
|
|
generatorshovel
|
3# |
Rank:none
Score:0
Posts:89
Registered:
02/17/2005
Time spent:
0 hours
|
(Date Posted:08/19/2005 12:46 PM)
Well, it works,,I ended up fitting an old 185 honda 2 piece head, with 25mm ex and 30mm inlet valves, but,,the 22cc combustion chamber volume was not going to work,,so I filled and reshaped it into a "D" shape, with a chamfer @ edges, with .0030" clearance between the piston crown edge ,and using yet another Tighe engineering cam regrind (399 grind) ,stainless steel valves (from 'ol Ivan) serco springs, the valves also miss the valve reliefs by .030".
As yet,,the weather has been against a full noise top gear try out (too windy) , but the power starts to change the exhaust note from 3,000 rpm , and Iv'e been somewhere near 8.000 rpm in 1st , 2nd , and 3rd gear,,with no noticable drop in the power , so it looks like Iv'e solved the problem.
UPDATE :- a new day dawns,,no wind,,7800 rpm in top with 15/30 gearing @ 75 mph
8400 rpm in top with 16/35 gearing @ 75 mph ------ time to lean it out 
2 weeks and countless gearing ,carb and jetting changes later ,the 75 MPH brick wall still remains ,,but,, plan "B" involves alcohol , and no,,not for me 
Cheers Tiny
--------------------------------------------------------------
It CAN be done
|
|
generatorshovel
|
4# |
Rank:none
Score:0
Posts:89
Registered:
02/17/2005
Time spent:
0 hours
|
(Date Posted:10/20/2005 2:21 PM)
Damn this alcohol is good stuff
Although the stock 28mm flatslide hated it,,Jeg's in the 'states had the answer,,an "alcohol ready" flatslide for 2/3rds the price of a stock carb here in OZ.
Unfortunately , the little honda idled @ 3,000 rpm (man,,those briggs and stratton jpowered junior dragsters must have grabby clutches !) But after a pilot jet change,,and a stock slide,,ack ack ack,,VAROOOOOMBAAAAAAH!, ackidy ack ackidy ack ack.ack,,bewdiefullll 
Road test No ???? , I installed my 150 LB son on the seat,,gave him a few pointers with the semi auto gearchange , save the honda "biscuit " gears mate,,and lemme know what Mr Honda's speedo tells you 
80 + a bees dick dad !,,WOW,,how many revs??,,dunno,,didn't look,,ha ha ha,,who cares,,it survived
All that remains,,is to get an official "flying mile" time card next march,,
mmm? I have a plan for 2007 ,,ha ha ha ,,ever seen a "laydown" 173cc XR 200 powered CT110 ?
--------------------------------------------------------------
It CAN be done
|
| Support us |
Just click the links below and your donations will make a difference here. |
|
|
|
Steve NZ
|
5# |
Rank:none
Score:0
Posts:6
Registered:
03/31/2004
Time spent:
0 hours
|
(Date Posted:11/26/2005 2:20 AM)
Reply to : generatorshovel
Hi, just spotted your post.
A few years back I built a similar motor (mostly early XL125 based) for local "bucket" racing. I ended up using the XR200 head and cam with a 34mm Mikuni.
I never measured the top speed (mainly raced on kart tracks), but the 34 made a vast improvement over the 28mm I had previously used.
--------------------------------------------------------------
Steve in clean green NZ
'74 XL350, '78 XL350, '04 CRF450, '95 CR250 and some non-Honda bikes too.
|
| Support us |
Just click the links below and your donations will make a difference here. |
|
|
|
|
