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Discussion Starter · #1 ·
MY PARENTS BOUGHT IT FOR MY SONS 6 AND 10 TOOK THE EXHAUST PIPE
RESTRICTER OF IS THERE ANY OTHER MODS I CAN DO NEED MORE LO END FOR LONG HILLS WE RUN TOP END IS FINE IT IS ONLY 1 WEEK OLD ANY
HELP THANKS
 
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Discussion Starter · #2 ·
The biggest problem I have with the Scrambler is their fully incorporated rpm limiter system. I am working on a cheap (near free) mod sheet on how to remove this useless system. Keep your eyes open for the info soon.

On the other mods, CHEAP means you can pull that funky air shorkel out of the air box or simply install a K&N RU-200 air filter;
Change the spark plug to a B8HS;
Pull the carb and open the main jet using number drills -- until the engine can take full throttle witout falling on its face (the K&N will allow a bigger jet size);

Moving to the "almost" cheap mods,
Pull the head and mill it so that you have a .040" clearance between the quench area of the head and piston;
Remove the reed block and bend out slightly on the reed that faces the front of the atv.

After you find that those mods were not quite enough,
go with one of my special deck height 70cc cylinders (bolts on no problems);
Add a pipe!!!!!!
Talk to me about some transmission mods to really make it move!!
 
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Discussion Starter · #3 ·
MY LITTLE GIRL RIDES A SCRAMBLER 90 CAN YOU,AND HOW DO YOU TAKE THE EXHAUST RESTRICTER OFF. ALSO I AM UNABLE TO FIND A REFRENCE TO THE BEFORE MENTIONED; K&N FILTER,TO REPLACE THE STOCK ELEMENT ON THE 90?
 
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Discussion Starter · #4 ·
The foregoing mods only apply to the 50cc model, especially the head mod as the 90cc head MUST be replaced completely.

The K&N filter "RU-200" can be ordered from any shop that sells K&N. Heck, you can order it from Kragen Autoparts. If you want to have it shipped with an outterwear, call Trinity Racing. 714-632-3434.
On the 90, remove the restrictor sleeve located above the carb slide, add the K&N and drill the main jet to .032" to start. Your next mods would include a pipe, head and cylinder height change.
 
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Discussion Starter · #5 ·
For parts for the 50 and 90cc Scramblers contact Billy Holt @WRH Racing 251-675-9906.
 
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Discussion Starter · #6 ·
bought my 7 year old a 50cc scrambler. she loves it. the promblem is; she has already out-grown it. I need to make it faster! I've already removed the snorkle and opened the box a bit. I've also punched-out the baffles inside the muffler and added more air to the tires(20lbs. to rear, 15lbs. to front). I still need to remove the restrictor plate on exhaust pipe(if there is one?) and add a K&N air filter(can,t find "RU-200", is that an old #?). also, what is the gap for spark plug you recommeded? I'm also looking into changing the front sprocket. any other advise?
 
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Discussion Starter · #7 ·
Trinity Racing http://www.trinity racing.com has the air filters. On the sprocket issue, just go and get the stock Scrambler 90cc front sprocket. When you add the air filter, you will find that you need to enlarge the main jet once again.
 
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Discussion Starter · #9 ·
Simple. (Caveat -- some people will tell you that drilling your jet is not accurate and that it will cause problems. I say BS. If the engine runs properly with the selected hole size, there are no problems. Besides, Mikuni does not supply jets for the VM17. HINT -- Holley main jets fit!!)

Take the carb off the engine. Remove the float bowl. Remove the main jet. Drill it using a 60-80 number drill set. Depending on the mods, I would start with a .032" drill, raise the needle one notch and see if the engine accepts full throttle. If it does not, go one size bigger until full throttle is achieved. Next check the spark plug to confirm jetting.
 
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Discussion Starter · #13 ·
i bumped the main jet on my sons Kasea 90 to a 33.5 and i have a few more things done to it nad im going to have to go bigger
i think 38
the stock on the Kasea was 28? im not sure its been a while
the stock carb is going and a 20 mm is going to take its place
 
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Discussion Starter · #14 ·
the stock main jet on a scrambler 50 is and 85. WRH has a good selection of mainjets in stock (251)675-9906.
 
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Discussion Starter · #15 ·
I don't mean to correct you, but I just pulled-out the main jet on the 50 Scrambler and it's a 75. I have a 77 1/2, 80 and 82 1/2 on order. Will try one of those when I get them. I'm looking for a thumb-saver. Is there such a thing?? Or , can I put a twist-throttle on this machine?
 
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Discussion Starter · #16 ·
The best way modify the thumb throttle would be to remove the oil injection and replace the stock cable. This will make the thumb throttle at least twice as easy because you will not have to be operating the carb and the oil pump with your thumb. If you would like a thumb extender you can get one at 1-800-858-4737 they have them on sale right now for $17.00.
P.S. Sorry about the main jet size. Billy is the one that handles most of the 50's.
 
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Discussion Starter · #17 ·
Hi! It seems that you`re the most knowledgable in the bunch, so here it goes. I bought my 7 yr old son a scrambler 90, what I`m wondering is what I can do to soften up the suspension without spending an ungodly amount of money. I`ve got the bike where it rips pretty good, with some of the mods all of you guys talk about. Any info would be helpfull, Thanks! Also I would like to hear about the tranny mods too! P.S. Any information from anyone else would be greatly appreciated and I hope I didn`t offend anyone by jumping in, or by how I phrased my question. Thanks again!
 
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Discussion Starter · #18 ·
You need to talk to Raptor720 he knows these bike like the baCK of his hand,as far replace it with a aftermarket shock that is adjustable it will cost you but its worth it
 
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Discussion Starter · #19 ·
Well, I'm done; at least for now. I would like to thank all of those who helped me, most notably: Raptor720. My daughters' Scrambler 50 is much faster and has more power now w/mods.
Here's what I've done so far:
front sproket from 90
went from #75 jet to a #82 1/2
raised needle in carb 2 notches
K&N filter w/sleeve
remove exhaust restrictor
new plug - BPR6HS
I would still like to put wider tires on it for more stability. Also,the ride is very stiff, maybe new shocks?
Anyway, thanks.
 
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Discussion Starter · #20 ·
Don't go to wide on the rear tires or the front end will push. I would use dura blue honda 250r rear wheel spacers to widen the stance. For tires and wheels I would use either 16x6.5x8 or 18x6.5x8 holeshots on 2-4 offset wheels depending on the terrain. A 68cc malossi top end and a pipe whould increase power beyond belief. To obtain a sorce for these and other parts call (251)675-9906.
 
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