I am rebuilding an engine & am at the gearbox stage, its a 150 special/pacemaker setup.
My issue is that the 3rd gear won't go into place, when I do a dry fit outside the engine casing it all fits in correctly, when it goes into the casing the 4th gear drops into place nicely & 3rd won't.
2nd & 1st go in without any issue. - Its just the 3rd gear I have issues with.
It may have the correct amount of teeth but is it the right diameter?
Also if I have my facts right 3rd on a pacemaker box differs between the early and late boxes.
May be the wrong cog!!
AL
An LI150 Special (Pacemaker) 3rd gear should have 39 teeth and measure 97.2 mm across.
Width wise, an early one measures 33mm and a later, stronger one, measures 33.8mm (this is measured "across 5 teeth")
It may be that the 3rd gear cog you have, although having 39 teeth, is from a GP200/ GP125/ LI125 Special (they all use the same box), or SX150/ GP150.
Due to this 3rd gear issue & the difficulty in finding one here in Australia I finally decided to take my SX150 gearbox & fit it into the Li150 engine I am rebuilding & buy an Li150 gearbox from Jet200 in the US for the SX - Are you confused yet?
I am rebuilding an SX150 engine as well, so they will both get the following set ups, assume these will work OK!
Li 150 Engine - 4.9 Drive ratio, guy buying it is on the large side so this should work well for him.
- SX150 gearbox
- 16 Tooth Front Sprocket
- 46 Tooth Rear Sprocket
- Chain to match
FYI, the Li150 gearbox was missing & had been replaced with what looked like a Pacemaker box until I discovered that the 3rd gear was the wrong size! Most of the engine parts for this Li150 was from a project that someone else had started & the guy had replaced some of the parts with SPAQ crap from Vietnam, so i am donating some of the parts that I am replacing in my SX150 engine to the Li150's, that way it stay as Italian as I can, only thing SPAQ left is the kickstart.
SX 150 Engine - 5.65 drive ratio, this is for me & I am looking for cruise around town & do the odd freeway trip.
- Li150 gearbox, this is an Indian gearbox sadly, but brand new, I am going to have the gears & tree tempered before I install it in the engine.
- 15 Tooth Front Sprocket
- 46 Tooth Rear Sprocket (AF 5 Plate Clutch)
- Chain to match
So cutting out the waffle....you've decided to swap gearboxes in your 2 engines (for reasons still unclear to me) and you've got a fat lad with an SX150 box on 4.9 and you wanting to do motorway (freeway sounds gay) journeys on 5.65 with a close ratio Li box?
I'd say the fat kid that loves cake is gonna need the close ratio box more than you, and his final drive should be approx 5.2-5.4 depending on top end, pipe and carb. You keep the shitty SX box for yourself (assuming you are lighter than fat boy) and gear it to about 5.2 (again depending on top end, carnb & pipe) otherwise you will be revving its nuts of on the gayway.
