Don't worry Drew; your not hijacking the thread (you are not calling us all c#nts yet)..
Take a port rubbing and do some measurements (port heights and sizes); we can all put a couple of cents in designing a pipe.
Then you can match it up to the closest miniMX, racing scooter (or comp chainsaw) pipe....
why 10000 RPM? they were built for rev'ing and if you really want to get anything out of it lift the limit a little more.
a question for you - what's the con-rod spec's (length, little/big end sizes etc)?
10,000 is probably a good idea as Drew will be too tight to rebuild the crank to handle more revs.
Husi I also found my 3.5" spoked wet only fits at the very back of the NF4 sw. Have to be lucky with gearing & chain length.
Don't you look at my accountant.
He's the only one I've got.
This must be the pre 91 swingarm (has the supports welded in right down at the junction rather than half way up the swingarm). 91 to 94 swingarms are 170mm wide and take the 3.5" rim. Was 93/94 they first offered the 3.5" rim, it drops straight. I believe some of the latter rims have a wider hub, this is why the NX4 sprocket bearing collar thingy doesnt work in the NF4, you end up with 5mm or so gap. Seems to be only part 3 (collar) from the parts manual that would need to be changed?
I call everyone cunt. The way some people call everyone bro, or mate. It's just my way.
Port rubbing is an unfamiliar term for me, but I guess from the context I stick a piece of cardboard down a cylinder and rub it to get an outline? That'll tell me how far from the top everything is? Given the stroke being set, it's possible to determine timing?
Someone posted in my build thread about rod sizes, all I remember is 12mm gudgeon, which means KTM65 slugs are a go as replacements.
Dave, you're more than welcome to come pick up one of the spare cranks and have it built to rev like fuck. I just don't have the money.
Hmm, I thought I had an '89 & two '91 swing arms pass through my mitts, I ended up using what I though were the 91s, they are different to the 89. The bikes came with 91 forks 90s are thinner/damper rod & pre adjusters. Weird.
I have found the 89 sprocket collar doesn't work on 91 wheels, its ~5mm too short
Don't you look at my accountant.
He's the only one I've got.
The 89 sa has a sheet metal web where the sa meets the brace, 90 thru 94 have a bit of square section joining the sa to the brace a bit further up.
Correct about the forks. The 94 rear wheel is 3.5 wide ie it has the NX4 rim with the NF4 hub and spoke pattern and has '93' cast into one of the spokes.
I'm gonna sell the good motor out of my RGV, to fund a half decent build. Got a clever (very fuckin clever actually) machinist who is willing to help with things, and very good mate who has lots of motorcycle bits lying around, and I do alright swinging spanners.
All hinging on one small thing. Me enjoying riding round small tracks, on small bikes. I know I fuckin hated riding an RGV at a full sized track.
yeah I sold an old bike to fund a few things, but all it did was clear existing debt & make me think I was rich for a fleeting time.
That Sketchy guy seems to like the RGV as a bucket chassis so I think you'll cope.
- that's not to say you won't whine like an old Valiant diff which leaked its oil out in the late 80s.
Don't you look at my accountant.
He's the only one I've got.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks