NQ-50 Faster?

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

Moderator: Moderator

Post Reply
User avatar
Bear45-70
CBR1000RR
CBR1000RR
Posts: 9682
Joined: Mon Jul 23, 1973 10:24 am
Location: Union, WA.

NQ-50 Faster?

Post by Bear45-70 »

What can I do with my 1985 NQ-50 Spree to make it faster or at least more powerful? We have real hills where I live and it just very challenged getting up them. I checked and both air inlets into the air box are open and the exhaust has no restrictor in the header flange. I'm stumped and need help.

Bear45/70
junkyspree
BMX
BMX
Posts: 39
Joined: Sun Aug 03, 2008 8:36 pm

Post by junkyspree »

Can't do too much, so I've learned. Everybody has got the same old answers. Remove your intake manifold and grind down the inner lip where the carb bolts up, with a dremel. That will help your take off a little. Drill 1-2 of your exhaust baffles (going to need a long bit to stick into end of exhaust pipe.) You could find someone with experience to port your cylinder and mill the head. You could bore your cylinder to an oversize and replace OS piston and rings. But with all that trouble and expense, you're not going to have a powerhouse. The NQ50 or Spree lacks a variable transmission, that's where the major restriction is at. So you're going entirely off the RPM's.

The little things stated above along with a few others will help, but don't have too high expectations. Here I'll go ahead and try to hit all the pointers to save people's time:

Make sure your airfilter and box is clean and secure (do not modify) and clean your carb and petcock very thoroughly. De-carbonize your exhaust pipe with oven cleaner or LYE (VERY DANGEROUS) or simply toss it into a fire overnight. Check your fuel lines, replace if ness. Check belt, replace if ness. Check clutch pad thickness if you have the right tools. If you're going into the motor, check your topend for any seizures or scoring and pop in some new piston rings and/or piston for appropriate bore. Hone/rebore/deglaze cylinder if ness. Oh yeah, and replace spark plug and gap to .26-.28 I believe. :D
User avatar
Bear45-70
CBR1000RR
CBR1000RR
Posts: 9682
Joined: Mon Jul 23, 1973 10:24 am
Location: Union, WA.

Post by Bear45-70 »

Well, the only thing you mentioned that isn't done is drilling the exhaust baffles. I would probably cut the exhaust open and redo it completely rather than just drill the baffles. I do have a service manual and was a professional 2 stroke (outboards) mechanic. Besides being a Nation Championship outboard boat racer doing all his own mechanical work. So the basics are not an issue. It's the preformance secrets I need. But other than a minor port job and a head cut, I will not be going farther than that. How much should I have the head cut? I don't mind using premium fuel.
Ziraya
Spree
Spree
Posts: 145
Joined: Thu Jul 31, 2008 11:49 pm
Location: Metro Detroit, Michigan

Post by Ziraya »

sorry to divert, but does nobody make a replacement transmission for the moped models that got * with the constant one? just seems silly that nobody would make the most effective mod you could have
junkyspree
BMX
BMX
Posts: 39
Joined: Sun Aug 03, 2008 8:36 pm

Post by junkyspree »

Actually, that was one of the first things I mentioned...but you got it! Shave off .020 on the head and use new headgaskets (check clearance)
Also if you're going to redo the exhaust, you're going to need to have the right backpressure which I'm sure you know. I've heard that a hole through the first 2 baffles is just about right where you don't have to worry about carb tuning.
Last edited by junkyspree on Sat Aug 16, 2008 7:27 pm, edited 1 time in total.
Kenny_McCormic
CBR1000RR
CBR1000RR
Posts: 4957
Joined: Sun Apr 16, 2006 11:51 am
Location: Southern Michigan

Post by Kenny_McCormic »

shave the head .020
drill 2 baffles out of the muffler
put a thin washer between the pulley halves on the drive pulley.
I am not a mechanic, nor do I play one on TV. Actually my advice is probably worth slightly less than what you pay to view it.
keithw
Elite
Elite
Posts: 392
Joined: Sun Apr 27, 2008 11:40 am
Location: North Las Vegas, Nevada

Post by keithw »

If you're up to it, build a tuned pipe for the exhaust. There is a good calculator in the advanced tech section. I had to add about an inch to the center section but other than that it worked fine. Be prepared to play with jets. I'm up to and 85 from a stock of 65. If you stay on top of the jetting you can deresrtict the air box, open up the intake manifold, raise the exhaust port a ring width, open up the passage between the exhaust port and the flange, build a tuned pipe, and fiddle with the final drive ratio. The Spree motor will turn 11k - 12k rpm, up from a stock 8k. As has been mentioned the biggest problem is the fixed transmission.

Let up know what you try and welcome to the "hot rod spree club". The motto is "they said it couldn't be done, so I did".

keithw
Honda Pal (Speed-o-scooter) JDM Spree with varator trans.
Honda Spree, 1985.
Another Honda Pal

Let's give it a try, how hard could it be?
Post Reply