RD350 project
- Thread starter Craigore
- Start date
dschief
750cc
Are you going to stay with the stock airbox? If so, jetting will be relatively straight forward. The DG's will require upping the mains 1 or 2 sizes.
I will say this, resist the temptation to use pod filters. 2 strokes work better with the airbox, or using the stock y-boot with a single large K&N or UNI filter. It has to do with the pressure waves caused by blow back through the carbs on the up stroke of each piston, it gives a psuedo super-charging effect for the opposite cylinder's intake stroke. If you do go with any aftermarket air filter arrangement, your jetting will require a HUGE bump. Your stock mains should be around a 110-120, the DG's will require a 125 to 130. An airfilter swap (with the DG's) will mean a jump up to around 180 to 210, and you will have to do some other work to, more than I can go into here.
Search those websites I posted earlier for Dave F carb mods. He is an old guy from Washington state, and he has done all the research for us over the last 40 years or so. His teachings will explain it all!
I will say this, resist the temptation to use pod filters. 2 strokes work better with the airbox, or using the stock y-boot with a single large K&N or UNI filter. It has to do with the pressure waves caused by blow back through the carbs on the up stroke of each piston, it gives a psuedo super-charging effect for the opposite cylinder's intake stroke. If you do go with any aftermarket air filter arrangement, your jetting will require a HUGE bump. Your stock mains should be around a 110-120, the DG's will require a 125 to 130. An airfilter swap (with the DG's) will mean a jump up to around 180 to 210, and you will have to do some other work to, more than I can go into here.
Search those websites I posted earlier for Dave F carb mods. He is an old guy from Washington state, and he has done all the research for us over the last 40 years or so. His teachings will explain it all!
dschief
750cc
http://www.aircooled-rd.com/default.asp?txtPage=davefriest.htm
Forgot he had this posted on the UK group
Forgot he had this posted on the UK group
I noticed that the main is a 140 with airbox in tact and stock mufflers. This seems to correspond with what the internet is telling me is correct. Does this seem right? I was thinking of fitting uni filters but would rather keep the airbox in tact based upon your advice... plus I don't have to spend as much loot to get where I want to be.
ps- I bought new Bonnie exhaust and am thinking of picking up one of those Innovate a/f units. What is the suggested ratio that I should be looking for? My friend with the R5 is running uni filters w/stock exhaust and blew a hole right through one of his pistons... my guess is that the previous owner ditched the airbox without swapping out the jets which caused it to run hella lean. I don't want to run into the same problem, I'd like to keep it stock with the exception of DG pipes and single K&N (or uni) filter in the airbox. Want a nice, reliable little ripper. I've even entertained the idea of riding it to the AMA vintage meet in mid Ohio this summer.
ps- I bought new Bonnie exhaust and am thinking of picking up one of those Innovate a/f units. What is the suggested ratio that I should be looking for? My friend with the R5 is running uni filters w/stock exhaust and blew a hole right through one of his pistons... my guess is that the previous owner ditched the airbox without swapping out the jets which caused it to run hella lean. I don't want to run into the same problem, I'd like to keep it stock with the exception of DG pipes and single K&N (or uni) filter in the airbox. Want a nice, reliable little ripper. I've even entertained the idea of riding it to the AMA vintage meet in mid Ohio this summer.
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dschief
750cc
The Dave F mods are to basically make the later RD carbs behave like earlier R5 carbs. My RD250 is totally stock so I have no reason to tweak it. My RD350 is a work in progress, and it will be getting the carb mods done, and my R5 is ready to roll as is.
I would suggest going for the mods, if for no other reason than you will be able to keep the main jet size down. The guys I have ridden with that have done the Dave Freist mods have some seriously fast machines.
I would suggest going for the mods, if for no other reason than you will be able to keep the main jet size down. The guys I have ridden with that have done the Dave Freist mods have some seriously fast machines.
have been making progress on the bike. removed the fenders, stripped down the tank and headlight ears to bare metal, and "rattle canned" the side covers, which came out great! cleaned the carbs, removed the heads to check ring, piston and cylinder clearance.
for performance mods, got the DG pipes (THANKS TO DSCHIEF!), y boot w/k&n, dale F carb mods, banshee type manifolds w/crossover tube, and a shit ton of jets come time for tuning.
made a gauge bracket out of aluminum stock and hand tools. was going to go the route of buying a mini speedo but I'm trying to keep the cost down
I measured out the inner gauge diameter, drilled and cut it out, then used a file to smooth the edges. it took a bunch of attempts and beer to get the gauge to fit into the hole (that's what she said). I had to keep going at it with the file
but alas, after many cheap beers, it fits!
As it currently is, the stock gauge cup and stock rubber grommet, though it doesn't look super pretty. I've been looking around the house for other things to use. I have a few thermos lids and some stainless steel water bottles that I might have to sacrifice to the gods of speed if they measure out correctly.
here it is all mounted up
need to get some u-channel gasket to put around the inner ring for vibration dampening and so that it fits in there snug like a glove
2 strokes rule!
for performance mods, got the DG pipes (THANKS TO DSCHIEF!), y boot w/k&n, dale F carb mods, banshee type manifolds w/crossover tube, and a shit ton of jets come time for tuning.
made a gauge bracket out of aluminum stock and hand tools. was going to go the route of buying a mini speedo but I'm trying to keep the cost down
I measured out the inner gauge diameter, drilled and cut it out, then used a file to smooth the edges. it took a bunch of attempts and beer to get the gauge to fit into the hole (that's what she said). I had to keep going at it with the file
but alas, after many cheap beers, it fits!
As it currently is, the stock gauge cup and stock rubber grommet, though it doesn't look super pretty. I've been looking around the house for other things to use. I have a few thermos lids and some stainless steel water bottles that I might have to sacrifice to the gods of speed if they measure out correctly.
here it is all mounted up
need to get some u-channel gasket to put around the inner ring for vibration dampening and so that it fits in there snug like a glove
2 strokes rule!
I'm looking for a cheap rd350 seat/pan. I stripped the fenders off my project and it looks silly with a seat with so much comfort!
planning on ripping one apart to the pan, reupholstering and running it low!
coming along...
tig welded a headlight guard to the ring, looks sweetttt
Found that my oil pump was no good so I am ditching it for now, along with the oil tank and sidecovers. Re-wired the bike completely and added a solid state regulator/rectifier unit (the RD has a separate regulator and rectifier normally like an early xs650). Bought some new high-output coils. Things are coming together pretty well. Probably going to split the cases over the cold winter and replace the seals just for the hell of it... never know what is in the bottom end of a 30-something-year-old bike.
ps- seat cowl is the ass end of an rd350 tank. going to tig it to a seat pan. will be keeping that the same as the tank- RAW! no problems with rust yet whatsoever.
DSCHIEF! You don't happen to have a spare electronic ignition laying around, do you :-D?
tig welded a headlight guard to the ring, looks sweetttt
Found that my oil pump was no good so I am ditching it for now, along with the oil tank and sidecovers. Re-wired the bike completely and added a solid state regulator/rectifier unit (the RD has a separate regulator and rectifier normally like an early xs650). Bought some new high-output coils. Things are coming together pretty well. Probably going to split the cases over the cold winter and replace the seals just for the hell of it... never know what is in the bottom end of a 30-something-year-old bike.
ps- seat cowl is the ass end of an rd350 tank. going to tig it to a seat pan. will be keeping that the same as the tank- RAW! no problems with rust yet whatsoever.
DSCHIEF! You don't happen to have a spare electronic ignition laying around, do you :-D?
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dschief
750cc
Man, that's looking great! I have a friend that does the same thing with the gas tank/seat cowl.
I used to have a brand new Nutronics and a used spare, but I sold them about 2 years ago. Once you get the points set, they are a hell of a lot easier to maintain due to the questionable reliability of the old Nutronics, which is not even made anymore.
There is a guy in NJ that makes an electronic ignition system for your RD that, by all accounts, is an excellent system. I'll try to find his contact info for you.
I used to have a brand new Nutronics and a used spare, but I sold them about 2 years ago. Once you get the points set, they are a hell of a lot easier to maintain due to the questionable reliability of the old Nutronics, which is not even made anymore.
There is a guy in NJ that makes an electronic ignition system for your RD that, by all accounts, is an excellent system. I'll try to find his contact info for you.
dschief
750cc
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making progress. just bought: coils, condensers, points, a hydraulic brake light switch, new battery, and some exhaust gaskets
oh, fitted a seat from a puch magnum as well and chopped the frame to fit. put some renthal bars with a cross-bar and some diy bmx peg frame sliders on since this photo was taken
oh, fitted a seat from a puch magnum as well and chopped the frame to fit. put some renthal bars with a cross-bar and some diy bmx peg frame sliders on since this photo was taken