Newly rebuilt motor not running at its full potential.
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Newly rebuilt motor not running at its full potential.
I just finished rebuilding my 87 Spree motor and it starts up and runs with no problem, and when I take it out around the block it only goes about 25mph flat and down hill and 15mph uphill. When its full throttle it seems like it chokes up and doesn't feel right. I kept the same piston and re-honed the head. I've read about a break in procedure that I am supposed to do before riding this thing, what is that procedure for a stock 87 Spree motor? I've also read that I need to add more oil than the oil pump will give on a new motor, how much? I am not very experienced with small motors so any advice is greatly appreciated.
Last edited by ashlanky on Mon Jun 14, 2010 2:05 am, edited 1 time in total.
Re: Newly rebuilt motor not running at its full potential.
did you get new rings? did you check the compression with a gauge?
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87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Re: Newly rebuilt motor not running at its full potential.
Yep new rings, my old compression tester says 20 psi, however if it was that low I don't think it would run at all so it could be that my tester is bad.
Re: Newly rebuilt motor not running at its full potential.
Did you hone the cylinder? It would not even start with only 20 PSI of compression.
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'83 Aero 80 X 3
'84 Aero 80 X 3
'85 Aero 80
'84 Aero 125 X 2
'84 Aero 125
'84 Aero 125 X 2
'85 Aero 50
'85 Spree

'83 Aero 80 X 3
'84 Aero 80 X 3
'85 Aero 80
'84 Aero 125 X 2
'84 Aero 125
'84 Aero 125 X 2
'85 Aero 50
'85 Spree
Re: Newly rebuilt motor not running at its full potential.
Yes everything was honed.
Re: Newly rebuilt motor not running at its full potential.
I'm thinking my poor performance is because I haven't followed any kind of break-in procedure. What would be proper procedure to follow to break this motor in? It has the original piston and head, just re-honed, and new rings. The engine is stock with no bbk or aftermarket parts. Would I need to add any extra oil aside from what the injector is giving?
Re: Newly rebuilt motor not running at its full potential.
climbing hills with a fresh bore and rings with no heat cycles(at lease 3-4) and low speed throttling up and down while riding about 2-3 tank fulls is a no no. do a compression check to see where your at if its under 114psi you got a problem. 114psi is the service limit for stock setup.
Nothing like getting stroked!
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Re: Newly rebuilt motor not running at its full potential.
So I go through a few heat cycles, and then only ride on flat land no higher than 1/2 throttle varying speed for around 2 tanks? After the heat cycles when I take it on trips trips of 1/2 throttle, do I need to keep those trips short or does it not matter if I take it around a flat neighborhood for an hour or so?
Re: Newly rebuilt motor not running at its full potential.
Also the area where I live is nothing but rollings hills, which makes breaking the engine in quite difficult, any suggestions with that?