Topped out at 30mph what to do now

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Knuckledragger

New Member
Sep 18, 2014
27
0
0
Milford Connecticut
I have a bike and it has a 6HP race motor from Jakes Custom Motorbikes all polished and ported with a notched and skirted piston, Diamond High Compression head, Mikuni VM18 carb, 40 tooth rear sprocket, Rocket Raceing CDI and a expansion chamber exhaust. My first rude was 10 minutes and not much power. 2nd ride it had more power and pulled hard and good throttle response. I am on the third tank and it tops out at 30 mph. I use ready mixed 40:1 stuff from Lowes that is equal to 92 octane and ethanol free. I feel that I should be at least hitting 35++ mph. I see stock motors doing over 30mph with a 44 tooth sprocket. I just bought a Suzuki RM80 expansion chamber and a KTM 85 silencer. Any comments or tips will be appreciated.
 

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Knuckledragger

New Member
Sep 18, 2014
27
0
0
Milford Connecticut
I just feel that with all the porting and notched and trimed piston with a Mikuni VM18 and a performance CDI with a high Compression Diamond head that I should be hitting speeds in the high 30mph if not mid 40 mph. I just ordered a 36 tooth rear sprocket and a Suzuki RM80 expansion chamber and a KTM 85 silencer. I don't know what else I can do to make it a speed demon **** ride. Maybe a Arrow reed box and jug combo. I just don't want to spend $220 on a new jug and reed box. That means a new and longer throttle cable and fuel line too.
 
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woogie_man

New Member
Aug 9, 2013
223
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0
Fargo, ND
Let it break in more. Mine right now with no mods is topping out at 30 mph. The only thing different is the exhaust, as stock one fell apart, and a 36 tooth sprocket.

Let it break in more, as the ranks is not broken in yet...get more miles on her and let her warm up.
 

Knuckledragger

New Member
Sep 18, 2014
27
0
0
Milford Connecticut
I weigh 180 and it pulls hard in the mid and it gets to top speed quick. The low end is a little weak but when you port and trim the skirt and ramp the piston for high rpm you loose low power as I am told (seems to be true ) I would say from 10-30 mph it pulls hard and gets there quick. The reason I say 30 mph is that I went by one of those speed trap trailers the cops leave on the side of the road and your speed is shown in BIG light numbers. I drove by it and it hit 30mph topped out. I would think that the police radr is pretty accurate. Thanks to all who commented.
 

Knuckledragger

New Member
Sep 18, 2014
27
0
0
Milford Connecticut
I paid way to much and I don't have ANYTHING good to say about Jakes bikes , build quality or warranty and attitude!! I could have built 2 of these myself BETTER for the money he charged me. Dont get me started on that! I don't want to piss anyone off but if anyone wants to hear about the problems the bike has just ask. And NO I would not recommend Him to anyone. I am thinking about replacing the clutch cover with his logo on it and tell people I built it. I though it would be cool to have a semi- famous actor with a great actor for a father (Gary Buesy ) build a bike for me. LOL !
 

Rudz

New Member
Jun 24, 2014
454
1
0
Tyler TX
The rocket racing cdi is the same one that's sold on eBay, I have one, it blows the stock cdi out of the water.

Let your engine break in, mine hits 30, all I did was open the manifold and exhaust ports. I haven't touched the jug, slant head with ngkbh6.


Get about 200 miles on it and then tune your carburetor.

That high compression head and carb should yield at least 40mph at your weight
 

Rudz

New Member
Jun 24, 2014
454
1
0
Tyler TX
Jeez guys, I'm starting to see a pattern here. Can't judge for myself as I have noticed dog in the fight, but, just know what I've read here's and elsewhere.
 

Knuckledragger

New Member
Sep 18, 2014
27
0
0
Milford Connecticut
Well I just put a RM80 expansion chamber on my bike and holy SH-t this thing pulls hard and hits 40 no problem now. Probably low to mid forties now. Take a look at my page and my photo album of the pictures of the bike with the RM80 expansion chamber. I have a KTM 85SX silencer I might put on but its heavy and I have to figure out how to mount it.
 

skitchfish

Member
Oct 27, 2010
222
0
16
Michigan
Well I just put a RM80 expansion chamber on my bike and holy SH-t this thing pulls hard and hits 40 no problem now. Probably low to mid forties now. Take a look at my page and my photo album of the pictures of the bike with the RM80 expansion chamber. I have a KTM 85SX silencer I might put on but its heavy and I have to figure out how to mount it.
I CALL IF WE WERE PLAYING HOLDEM! Show me a pic of your machine!
 

skitchfish

Member
Oct 27, 2010
222
0
16
Michigan
Excuse me, looked at your album, now way less skeptical, sorry please except my apology. I still think your holding your handlebars by the stem in a aero tuck position! LOL! Is that a 38 or 41 tooth and where is your gps? That's a very different head and I'm still checking out the jug.
 

Davezilla

New Member
Mar 15, 2014
2,705
10
0
San Antonio Texas
Nice job with the expansion chamber... they do wake up these engines very well... I'm using a modded KTM50 expansion chamber on mine with really nice results, before that I was using an old pocketbike chamber grafted to the stock pipe which worked great too until it cracked at the bracket and the metal was too thin to re weld, but the KTM does perform a bit better... Pretty much any 50 to 125cc dirtbike pipe will do good once modded to fit.
 

nelsonk1969

New Member
Sep 29, 2014
63
0
0
Lake Worth Florida 33467
I have a bike and it has a 6HP race motor from Jakes Custom Motorbikes all polished and ported with a notched and skirted piston, Diamond High Compression head, Mikuni VM18 carb, 40 tooth rear sprocket, Rocket Raceing CDI and a expansion chamber exhaust. My first rude was 10 minutes and not much power. 2nd ride it had more power and pulled hard and good throttle response. I am on the third tank and it tops out at 30 mph. I use ready mixed 40:1 stuff from Lowes that is equal to 92 octane and ethanol free. I feel that I should be at least hitting 35++ mph. I see stock motors doing over 30mph with a 44 tooth sprocket. I just bought a Suzuki RM80 expansion chamber and a KTM 85 silencer. Any comments or tips will be appreciated.
If you have gone through the break in procedure properly and all the basics have checked out including the scheduled maintenance you might check out this company as they may have some coatings for your motor that may help where you need it. before you discount it I recommend reading everything this company has to say about two stoke motors even if you decide going a different route the information they have may give you ideas that you may have overlooked.
 
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