May 19, 2013
Suzuki GP125 engine strip down
Here are some more internal photos of the GP engine as I pull it down. I ended up drilling most of the phillips head bolts which hold the casings together as they were corroded down the thread. What a stupid idea it is to use a phillips head, honestly.
This last photo is of the tiny GP gearbox assembly. I wanted to show it to give you an idea on how a motorcycle gearbox works (although similar to a car) in translating the up and down movement of the gear changer to a change in gear. When you push up or down on the changer, a mechanism spins the grooved barrel in the top of the photos. In those grooves are the gear selectors which move left and right depending on the groove. The selectors move the gears on the input and output shafts which engage with each other to drive different combinations of gears and therefore ratios.
March 23, 2013
My dad and I went down to Te Puke – pronounced tee pokee not puke ie vomit – for the fifth round in the north island F4 series the other weekend. To say it was a great event is an understatement! I spent Friday night after work and Saturday morning building a new/quieter exhaust so I didn’t get black flagged. We arrived at Te Puke around mid day and jumped straight into practice then qualifying. I set a horrible qualifying time due to never having seen the track before, loosing out on the first practice session and a tune that wasn’t playing fun with the new exhaust set up.
Super solid weekend, cheers again to everyone who helped out, organised and drank beers with us.
Reagan put in a ridiculous 42.955s lap, brian broke two bikes after qualifying third and pushed the FXR over the line, I got smoked by B grade half due to a ill tuned bike (other half cos I suck), Warrick fended his son Josh off until he conceded (that would have been an amusing drive home), I believe Mel got her knee down, Will stepped up the pace in B grade, the track was bone dry and fun as hell…
… aaannnddd my old man took some photos of us. Cheers dad. A successful first away meeting for myself and I can’t wait for the next one.
March 1, 2013
Last weekend it was round 5 of the AMCC F4 series at Mt Wellington. I palmed off my camera to my dad like usual but this time with the 300L lens on the end, oh yeah.
It was such an awesome day and improved on my times quite a bit! I felt comfortable on the bike and I ran a new pb of 31.407 seconds anticlockwise. The last meeting my PB was in the mid 32 second block and I’m stoked it only took 4 race weekends to get into the 31 second block. Avalon Biddle was racing on Sunday who races a Suzuki GSR600 professionally and used to race a Honda RS125.
I also tried my best to learn some riding skill from Avalon, Gavin, Nigel and David who lead from the front. Unfortunately the GP125 engined RS125 which Avalon was riding was leaking gearbox oil into the crank case of the 2 stroke and fouling plugs but I’m kind of grateful for it because it let me try and follow when she overtook me haha.
The below photo is a pass around the outside of Warrick in the sweeper just after passing me in the infield, that’s some corner speed right there!
Congrats to Nigel for a new track record of 29.436s anticlockwise, a real sight to see!
I had some good battles with Warrick, Karl and Neil (mini motard)! Great riding guys
Huge respect for Karl (following me in the above photo) who put in a 30.9 second lap on a 13hp FXR with standard wheels and 5 year old worn out skinny slicks. I have some serious learning to do with corner speed clearly! It also goes to show how little you have to put into your bike to be competitive at Mt Wellington if you have the right skill.
Thanks Kamil, Cully, Tim etc who ran the event and to the flag marshals as always. Cheers dad for shooting the photos
January 29, 2013
Tim on a borrowed RS125 frame with GP125 engine
I spent my Saturday and Sunday at Mt Wellington for a practice round and a non points race day. Having not raced since November, I was eager to get as much track time as I could handle which consequently ended in my body now being wrecked!
It was a really good weekend of bikes with clear skies and a breeze to keep us slightly cooled. I let a few of my mates have a go on my FXR which should hopefully kick them into gear and mean they’ll soon be out there. During the Saturday practice I made the most of my opportunities to follow Brian and others where I could in the hopes their riding ability may rub off on myself. Brian gave me a few pointers on braking which helped hugely and lead to setting a new PB of 32.61s anticlockwise. On Sunday I improved on this with a 32.20s anticlockwise and I’m eager to keep the ball rolling into the 31s bracket! Thanks guys, I appreciate the hell out of any guidance I can get.
5 lap sprint anticlockwise with no grid order (first on the grid gets pole) then straight after returning to the pits, back out for a 5 lap clockwise sprint
10 lap race around ‘the ring’ (midfield coned off) anticlockwise then straight after, clockwise 10 laps. Again no grid placing.
Borrowed bike race – anyone can enter as long as it’s not your bike – 10 laps clockwise then 10 laps anticlockwise around the ring.
I swapped bikes with Rick’s son Will who rides a CBR150 with cams, exhaust, carb, which was really fun! It had much better throttle response and seemed as fast as my FXR (which has more work done to it) although I need to work on the jetting of my bike still. The CBR150 hasn’t been on the dyno before but I’d love to over lap the curves between bikes for a comparison.
Thanks to all that helped out and organised the day, great fun!
Tim on his own Aprilia RS50
Cully’s FZR250 frame with GP125 engine
Will on the CBR150
and again hustling with John in the midfield
Andrew slipping out of first position during an anticlockwise ring race
More to come
January 25, 2013
I made some clip on bars this week after work for the GP125. I’ve very stoked to have them at a more suitable height! Now I just have to cut off the front and rear foot pegs and make some new ones to correct the seating position.
The bars are currently at quite a shallow angle due to the bulk of the factory tank. I’m not about to chop and weld it but man I wish I could! I’m toying with the idea of making one from scratch in the search for less mass and better fit. I suppose I’ll see how I get on.
The above are two reference images including the bars. Note the frame shape, I’m hoping to change that…
January 23, 2013
I just realised I never got around to posting any photos from the Sunday racing in November! That… was a very good weekend.
The Saturday was the North Island series round which I managed pole position in B grade but wasn’t able to convert it into a win up against Dean Miller on a 70cc water cooled 2 stroke Derbi (who’s also a very smooth rider!). I got 3rd, 2nd and 7th (if I recall correctly) when I stalled on the grid, I was definitely too eager to get ahead of Dean.
The Sunday was a 40 lap race for anyone who didn’t have a partner or didn’t desire to compete in the 2 hour endurance race. Since I didn’t have a partner and I knew how large the field was (stuffed full of incredibly fast riders) I decided to give the 40 lap race a go. My riding fitness isn’t quite what it should be and my arms were stuffed after riding hard for approximately a half hour. The race wasn’t what it should have been with many quick riders who usually race in the grade going for the 2 hour. I took out first place however, and at the same time, my first motorcycle win, stoked.
So now I’ve moved out of the frying pan and into the fire as they say as I put myself into A grade. There is a meeting this weekend at Mt Wellington and with my bike running better than it did I’m eager to get my knee down on the floor where it belongs.
Dean Miller and myself onto the grid straight
January 21, 2013
So here it goes… the GP125 is in pieces, the engine is out, the unnecessary road gear is in the bin, clip ons are 3/4 done and I’m studying 2 stroke tuning like a fat kid on a sugar high.
Some reference photos of the engine because I’m yet to see any decent quality ones online:
October 8, 2012
Note: old man in green is my old man. The guy sitting on the bike with a broken arm and doing the honours is Kelly (racing related injury) who I bought the bike from and who built up the engine.
I got the bike on the dyno on Saturday and ran her up to tune the new carb and exhaust in. The last time it was on the dyno it had a hideously loud but well functioning megaphone exhaust which has been swaped off for something a bit quieter to keep the peace. Whilst it was making almost as much power as it was with the megaphone (19.6 vs 20.4hp), the curve was on the piss. A few changes in pilot and main jets and resetting of the fuel floats filled in a large hole in the curve.
Unfortunately I didn’t have a new plug with me because it seemed that the current one was a bit poked. A tighten up of the gap found a bit more in the curve but we left a little disappointed in the result. Although it went off the dyno a huge amount better than it did when it rolled on, the illusive megaphone curve taunted me whilst trying to get to bed that night. I’ll get a new plug and consider having a go at moving the needle around but I’m really dreaming of how to quieten down the megaphone to an acceptable race level.
I painted the seat frame on Sunday which improved it’s looks drastically but with summer holidays coming closer and my wallet tightening further I don’t think I’ll paint it until next year… maybe. Racing is on this weekend and hopefully the rain stays away because I am beyond addicted and I need a hit of racing.
September 15, 2012
Finally! Man that took far too long… that is for me to own a race motorbike. So my dad and I picked her up today for a very good price considering the work that has been done (spec list below). Honestly I think Suzuki FXR150s are pretty damn ugly but even when they’re almost stock they are very good value for money. There are limitations however and this bike has already had a few of them scratched off.
At this time it’s pooring with rain outside and the monthly bucket race meeting is this weekend. I missed the practice today because we had to pick this up but I did get a chance to give it a punch down the deserted country road and was very pleased. These make approximately 16hp from the factory and this one has been dyno’d at 20hp with a healthy torque curve which is the main thing given the nature of the tracks we race at.
I took a few things off the bike tonight and swapped the sprocket for a larger one for tomorrow but I also started to plan a new colour scheme. I’m a bit bummed I don’t have fairing space to play with – because they’d just get obliterated – but I did a quick photoshop for myself and I’m psyched to make this thing my own. I bought a back protector today so now I just need some proper boots and gloves and I’m set with gear.
Spec/modification list and other stuff I picked up:
After market high lift cams and heavy valve springs (3 meetings on these)
64mm piston (6 meetings on this) and copper head gasket
28mm Keihin flat slide carb
Custom stepped header and muffler (plus a very good but loud mega phone exhaust included)
12 tooth front sprocket, new 47 tooth rear sprocket and new chain. 48 and 49 tooth sprockets included
GSX250R wheel conversion with Dunlop slicks
Standard wheels with wet weather tires
Raised footrest hangers
Clip on bars
KX125 quick action throttle
And a bunch of useful spares
The person I bought it off had this to say about it: “The bike was used for the north island series with several wins and top 3 placings, finishing second overall. There is plenty more scope for development but is still up there with the best”. I’m stoked,let’s get out there.