Two Stroke Racelab

Temps are pretty high here in Greece and some missing parts are keeping me back... though I've managed to spent a couple hours on the nf4 project.I hope pics might be of some help to any people out there enjoying similar projects! Here are the NF4 transmission ratios:  First number for main shaft, second number for countershaft.  1st Gear  17/31 2nd Gear 22/33 3rd Gear 24/31  4th Gear 26/30  5th Gear 27/29  6th Gear 24/24  Well, there is always time for beer. Water pump ready. These parts were totally missing.  Some good plates in.  Electrics test fine while on the bench. I hope this counts under load as well. Only time will tell. Cylinder is newly replated though need some chamfering prior installation. The engine came with a  HRC piston that sadly is out of spec but I will keep it for the first start up. I will have to order a new piston soon. 

It's been a while since I've last rebuilt a single cylinder engine and I've forgotten how dead simple and fun it is. The nf4 engine that I have, doesn't seem to be in a very bad shape, so everything should be quick and easy.  I think I should replace the carburetor and intake manifold with the proper nf4 parts. So far so good though primary gear bolt and washer are missing; some clutch parts are missing as well. No big deal... Have I ever mentioned that I hate Yamabond? What a mess...       Anyway, all newer pics will now be in reverse order I reckon...  Crankcase is now clean and ready to be reassembled.

Mostly working at night, humming along, with a glass of wine. Trying the best I can to slow up and enjoy the process, as the rolling chassis of the NF4 project is coming to an end.  Not a lot of much interest, mostly bolting parts together, installing R-clips and safety wire. Still some pics look interesting nonetheless.  Some new fairing mounts were made out of 16mm aluminum tube, mostly to use them as an alibi that I did something more other than just bolting parts. I couldn't justify this post otherwise. LOL  The handmade rearsets were made by Pete from Banks Racing. Check out his work and products at  www.banksracing125.com

Time passes by as a two stroke bike  and this blog is now two years old.  Many thanks to all the two stroke junkies around the world that keep visiting this blog. More than 30.000 visitors and 107.000 page views until now and keep going...  Please, keep in mind that I'm always open to new ideas, comments and opinions on blog structure, suggestions on new articles etc. Your participation is more than welcome and whatever you have to put on the table, I'm all ears.  Keep the two strokes alive.  Nick 

Well, here is the first episode of the Honda Rs125 Nf4 project. Enjoy!  All parts were disassembled and thoroughly cleaned so I reckon it's about time to start the resurrection of this little bike.  This is a '89 model though previous owners have installed quite a few later nf4 parts and this counts for me as well when availability is short. After all it is a racer...! The chassis is a '89 NF4 RF model and swingarm is from a later '90 bike.   These are the forks the bike came with. They have a rebound adjuster so I think they might be out of a '92 and later model and this should count for the front gold master caliper as well.  Usual suspects... stubborn brake piston on the rear caliper, all parts were completely dismantled and now in perfect working order. I still have some issues with the front caliper though.  I hate the red paint theme on the caliper but I hate painting more, so I'll stick with it as it is for now... gladly I won't b...

It's about time to start working on my Honda Rs125 nf4 bike.  This is a bike that I bought about a year back, in not that great shape and with quite a few missing parts. I had made a list with the parts that are missing and/ or malfunctioning, that is now getting short. So, it's time to start dismantling the bike, put some new bearings in and inspect for any possible issues etc.  Some missing parts are already temporarily fitted in there like a new set of rearsets, a newer swingarm, a water pump and cover and some miscellaneous bits.  This is how it all begins...  Here we go again... stay tuned!

Here is a rather simple construction that can get you out of trouble if your battery is flat while you are at the pits. You need a battery case box that can hold ten AA sized batteries and a suitable connector for your wiring loom. Batteries should be rechargeable but in case of emergency any type can be used.  The output will be about 14-16V DC depending on the batteries being used and will have a capacity of more than 2Ah at 12V DC.  Dimensions of the battery pack are 58x78x30mm and total weight including the cells is 280gr.  Great for :  * backup battery for total loss ignition systems * run devices on the pits, like ignition strobe timing light etc. * easier accessible and cheaper alternative for the stock Yamaha TZ250 battery pack

High density foam sheets like closed cell foam, neoprene, heat and soundproofing foams etc can serve a few uses on a motorcycle.  The clock panel on the Honda Rs125 Nf4 project was in bad shape and had a questionable paint job; hence off it goes to the bin. A new panel was fabricated out of some closed cell foam sheet, by using some scissors and a cardboard template.  Same goes for the damaged oem seat pad... Keep in mind that closed cell foam can be used as silentblock for some applications as well e.g fuel tank mounting.

Finally finished the fabrication of the expansion chamber for the Yamaha Z125 dragster bike. I think my skills got a little bit rusty and I've made quite a few mistakes during the construction but I consider the result acceptable nonetheless.