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Hows The 4/stroke 125's Going?


marky g
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Thanks for the reply on the exhaust mod Mike, I'll try it this week.

Latest hints and tips for everyone from yesterday's trial.

1 - The Sumpguard extensions I fitted worked excellent - Gives much more confidence riding up rocky streams (between rocks) - a few scuff marks on them, so they obviously work ! - Interesting to note that the 'Long Ride' version in the photo has extensions fitted.

2 - Keep an eye on the Plug Cap. I had to retire after a lap and a half yesterday, the bike just wouldn't run. On tickover it would stop, then take a while to start, then run for a while, then stop. This went on for a long time.

It was pi**ing down, so decided to pack in, as the last thing I wanted to be doing was push the bike 2 miles through the mud back to the car ! - Anyway, traced the problem to the plug cap. The outer sheath had pulled back from the plug cap, and the HT lead was shorting onto the fins on the barrell - hence intermittant starting, and missing when running and revved.

Solution is silicon and copious use on black insulating tape !

Jesus, I should be a Scorpa development rider - but I'm crap (but maybe thats what they need ! - Must go, just about to e-mail Scorpa France with my CV !)

John.

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And before the bike got dirty (SY250 longride kit maybe???)

I wouldn't know; I'm still waiting on my Long-Ride kit to arrive! You'd think it was on a slow boat from China instead of France; ordered it in late summer last year and got the bike in November. Still waiting for the seat/tank which was ordered the same time as the bike... :)

I have heard it should be here soon; maybe this week I'll get lucky? :D

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I had a go on Bob Ginder's new comp model 4 stroke last week at B&J. Bob already had the 143cc kit on his and some exhaust mods done. My only four stroke experience has been with my own bone stock '74 TL125. What a difference!! I was really impressed with how easy it was to lift the front end around. No hesitation at all. I also noticed how smooth the power came on, nothing like my '98 TXT270. The bike pulled steady in second gear and the smooth power delivery really makes the bike hook up. The components and build quality are A+ and the rear fender looks much better in person than photos. I think for my level of riding, it has to be the perfect bike. Never noticed the cable clutch, it worked great and I didn't use it that much. I was also impressed with how light and narrow the bike felt. Bob said he weighed the motor out of the bike and it weighed 53 lbs. For any doubters out there, first place in the Expert class at this weekends trials in Hattisburg, MS was won by Dustin on a four stroke Scorpa. Best of all, it just sounds cool!!!!!!!!

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Well, I guess it's time to share what we have found out about the 125 Scorpa. Don's been after me for quite awhile, but I wanted to have spent enough time with it to be confident with our findings.

First of all, we have found ours to be a great bike and, with a couple of changes, we were able to achieve excellent results, even in the Expert class.

So now that we have gotten over the look of the plank of a rear fender (I've not found it to affect the bike's performance and it makes it easier to find in a crowd), the first thing I felt that needed attention was the clutch. Way too grabby. So we disassembled the bike, spread the clutch out, and started its inspection. Determining that oil flow was less than needed, we did some machining to the steel plates to increase the flow. We also added one of our lever assemblies we use on our vintage bikes to improve leverage. Instant Success!! The fiber plates swelled with heat, however, changing the engagement point; the fiber plate composition was changed to a less temperature-sensitive composition. We then added a new cable made from our more flexible inner wire and nylon-lined casing. This cable flows better around the bends it has to make.

It's so much better that most who have tested see no need to play with hydraulics. We are offering the complete set-up as a kit (see our site at )http://www.bjracing.com/sy125f.htm

There also seems to be quite of bit of interest in the big bore kits, so here is a short rendition of what's happening there:

The TTR kits are motocross kits and have too much compression for our needs in trials. We have developed a 143cc kit with the proper ratios. It adds a considerable amount of torque and allows the use of 2nd gear on climbs; I still use 1st most of the time.

The 143cc kit requires only cylinder modification; there seems to be a lot of talk about a 160cc kit which we are also working on, as well as a bigger kit. But you should know that anything over the 143cc kit will require splitting the engine and boring the cases to accept the larger sleeve. The 143cc is ready now; I will keep you posted on the larger kits as we get further along with their development.

We also have a new core for the silencer. Keep an eye on our web site for other set-up and improvements; I will post some of them here.

Bob

B&J Racing's SY125Fbob%20on%20scorpa2.jpg

Edited by BGinder
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Glad to se you finally made it over here, Bob! It's nice to hear all about the SY125 development straigh from the one doing it. I guess we'll see you guys at the Nationals on Saturday; don't know which section I'll be checking but I'll be there along with the SY! I'm looking forward to the chance to check out what you've done with the 125 after the day's activities...

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:PThe Scorpa 125 had a very good showing in Tenn.last weekend.Dustin Ginder rode in the ES class and had a win on sunday.It did not have any problems getting up and over the biggest of obstacles in the sections.Very strong running little bike.JR :wacko::huh:

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  • 2 weeks later...

I think that scorpa have made a big mistake with the back mudguard on the 125 4t. In mine and many others i have spoken too opinions they would rush out and buy one if they had stuck to the original idea of basing it on the original sy250. I have yet to ride the one thats in our club so my opinion may change!

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Hi all,

Just a quick update on my beast - have installed a full stainless system on my 125 - custom made by the guy who did the first work on the Britten's (or so Im told). Top quality work (see attached pic). The muffler is a bit bigger (sits lower) but so far is no more vunerable than the standard one. Weight is roughly the same - so the maker says.

Performance: First of all - it sounds unreal - better than the agricultural noise the standard one makes. Overall power maybe slightly higher but is now more responsive with much improved top end. Steep hillclimbs are now less daunting but still will not pull second on anything steeper than a disabled wheelchair ramp (also due to 110kg rider).

Overall: Money well spent in my opinion - makes my one-off bike (for Australia) even more unique. Although, the muffler is quite dear so maybe a B&J baffle kit mated to this header would also be good.

Unrelated (to exhausts) - has anyone got maore info about the scorpa tech release about the weak bashplate. How would I get a Narita or Crosswaite strength basher?

Cheers,

ben r

PS easy pull lever mentioned in earlier post is a godsend - put the cable in the middle spot for easy pull and it still has good response. The easiest spot is light as a feather but clutch response is heavily affected IMO.

post-10-1082540111.jpg

Edited by Ben_r
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mine's ready too ;-) Just waiting for the some decals to arrive to finish it off.

The tank holds a tad more than the std one, the front pipe proved too pricey to get in stainless so I had it chromed......and the I've had some 'proper' bash plate extentions added on B)

I took MR's advice and cut out the 4 steel rods that were in the silencer and it sounds much better for it!, I also cut down the rear guard and trimmed the sides of it up a bit to try and make the rear end look a bit better.

As soon as the comp guard is available I'll get one of those........running it in using Castrol GTX before going over to fully synth oil..I'll get some better pics when it stops p***ing down here in 'sunny' shropshire

post-10-1082578931.jpg

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