1972 DS7 The Row Boat

Re: 1972 DS7 The Long Road- monoshock conversion done

Thanks Brad. I posted the transmission spreadsheet that we talked about in the 1 800 cafe help.
I still got a cup of rust leftover from that pic if you need it.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

clem said:
I may try to find someone to split the deal with when I buy it.
My phone better be one of the first ones to ring ;) :p
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Clem, bike is looking great! Wish I had gone with EX250 wheels now instead of EX650, I might still swith the rear for the 250 wheel.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Looking great Clem! Good to talk with you yesterday as well. Keep it up, and like I said on the phone; if you need anything for the bike, just shoot me a call.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Redbird said:
My phone better be one of the first ones to ring ;) :p
Chris, Ive got a buddy that digs bikes but never pulled the trigger on one yet. If he doesn't bite, I'm calling you man!
johnu said:
Clem, bike is looking great! Wish I had gone with EX250 wheels now instead of EX650, I might still swith the rear for the 250 wheel.
Thanks John, I'm still tripping on your bike. It's bad dude. I really think that there are engineers in Austria at the KTM factory turning out those trick orange parts for you as we speak.
VonYinzer said:
Looking great Clem! Good to talk with you yesterday as well. Keep it up, and like I said on the phone; if you need anything for the bike, just shoot me a call.
Same here Mike. I think that I remember shaking your hand now last year when I was dropping off the jerky at the tent. I booked a room today for Barber so I'll be there for sure this year but not sure what I'll be riding. I'll be looking for DTT name tags or dudes with moonshine hangovers! Haha

Alright. I got the cases buttoned up. I used the old rusty bolts for a real hipster retro look...not really, Im going to replace them slowly one at a time and put lock washers on the as per MD from PA so that the engine does bust open when it's screaming down the road. I straightend out a couple of bent fins and painted the cylinders but didnt take pics of that yet.



 
Re: 1972 DS7 The Long Road- monoshock conversion done

Well I received confirmation yesterday that the JL pipes won't fit my bike with the mono shock linkage. Bummer but at least now I won't get flogged by Von over them. I'm kind of interested in rolling my own but really don't know where to start with dimensions. Any one chime in here please. I'll be surfing the net doing research.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Dg number are very nice for a stock/mild port bike
 
Re: 1972 DS7 The Long Road- monoshock conversion done

You got those numbers?
 
Re: 1972 DS7 The Long Road- monoshock conversion done

clem said:
Well I received confirmation yesterday that the JL pipes won't fit my bike with the mono shock linkage. Bummer but at least now I won't get flogged by Von over them. I'm kind of interested in rolling my own but really don't know where to start with dimensions. Any one chime in here please. I'll be surfing the net doing research.

What do ya want for those pipes? ;)
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Mike, I actually talked to Jim at fast from the past before I ordered them. But wait ! You clowned me about them but now you want a set?
 
Re: 1972 DS7 The Long Road- rolling my own

I started doing some reading(Gary Jennings book) and am seriously considering making my own chambers. Looking forward, I think that it may be best to set the pipes up for a stock RD350 since that is the cylinders that will go on once the funds become available. Problem is that I don't have the exhaust port timing nor the piston to exhaust flange measurement on the 350 and don't know if it is the same as the DS7 or not. It would be great if one of the fine fellows here could point me in the right direction with this. I know that I probably won't end up with a perfectly tuned pipe but I am looking at this as a chance to learn about the principles behind the two stroke. Back when I was racing motocross we would just jet, gear and buy off the shelf pipes from pro circuit or FMF. I had a guy in the Baton Rouge area that would do porting but we never made a pipe to the modified porting specs. This will probably be a slow process but I'm cool with that. I made the mistake of trying to put a timeline on the build but see now that it was a bit foolish to do so.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Go bug redbird about the extra dg that the cathlic church distroyed ill bet there good enuff to measure
 
Re: 1972 DS7 The Long Road- monoshock conversion done

In addition to Gordon Jenning's book, Graham Bell's 'Performance Tuning in Theory and Practice' is well worth a read, especially regarding chambers. If you can't find a copy I can send you a pdf version.

All the porting etc. can be as good as wasted if the pipes aren't suitable.

Crazy
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Brad I was thinking about hitting him up to get some measurements to compare to what I came up with.
Stroker, I did find a download of Bell's book along with a free software ...2Tb I believe. I did most of the calculations based off of Bell's ranges of angles for the diffusor and baffle. The math seems to be the same between the two but it appears there is either personal or proven criteria that separate Jennings and Bell. My wife keeps telling me to just go buy a set of pipes but I think that this may be a good learning experience for me.
I put the engine in and got the clutch installed. Now I need to finish blasting the side covers so that I can polish the raised edges before they get powder coated. The wrist pin bearings that were sent with the crank were too wide for the 250 pistons so a new pair are on the way. I added mounting brackets to the seat and got a new oil tank that will fit under the seat (stolen from JohnU) so that will be a little more fab work. It's getting there.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

The bike is looking great Clem!

Are you aiming for peak power with your chambers or going more for mid-range spread?

Crazy
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Low to mid hit. As long as I can break 70mph I'm happy! Lol! I went with the upper end of Bell's multiplier for the header legnth. Like around 8. Thanks for the good words.
 
Re: 1972 DS7 The Long Road- monoshock conversion done

I'm with you on that - I much prefer a bike with strong acceleration than one that only has high top speed.

Crazy
 
Re: 1972 DS7 The Long Road- monoshock conversion done

Yeah, the 70 mph was a joke referring to my cb160. Everytime I pull out on the highway I almost feel like I need to push.Haha.
 
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