gt250 reed valve engine

Retro, Wild, Cafe, etc. The stuff only your imagination can come up with.

Moderators: Suzsmokeyallan, oldjapanesebikes, H2RICK

Post Reply
dollydog
Yeah Man, the Interstate
Posts: 532
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

gt250 reed valve engine

Post by dollydog »

finally [nearly] finished the reed valve conversion for a normal t/gt250. can't try it yet, even though it's now in a frame and all piped up with fuel and oil. haven't got a throttle cable, so i've got to wait for that, and the supplier sent me the wrong battery, so i'm waiting on that as well. barrels milled out to an oval, and i built the rest myself, all the plates and everything. a 'mate' welded them for me, then relieved me of £70 :cry: rd350 reeds in atm. will try them first and have a mess about with the carbs until it's something like, then eventually [hopefully] road test it. this is the engine sat on its perch before i slotted it into a gt250a frame. boost bottle not fitted there due to breaking it. i made my own out of 28mm and 16mm copper pipe, soldered together. unfortunately i was a bit heavy handed and snapped one of the 'legs' off when i was fitting it :D
cheers, dd.
p.s. yes, that is an hydraulic clutch 8)

gt250 reed valve engine:
Image

oops, fogot to post the other side:
Image
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
User avatar
jabcb
Moto GP
Posts: 3750
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: gt250 reed valve engine

Post by jabcb »

Interesting upgrades. Looking forward to see how they work out.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 project & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
dollydog
Yeah Man, the Interstate
Posts: 532
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: gt250 reed valve engine

Post by dollydog »

finally ran properly for the first time this morning :up: i had to build 2 slopes for the inside of the box section [at the bottom], which i made out of square section aluminium and involved a lot of filing. where they sit was originally filling up with fuel, so these are acting as a kind of stuffer, as well as directing the fuel up to the intake manifold. should really have done it in the first place, but i got over excited. no exhaust on atm, due to a complete lack of room to fit them, but hopefully i can take one of the other bikes out of the shed and make myself some room. engine just sitting in a frame, wired up and temporary fuel tank on. but it runs, so that's the hard bit done :D
cheers, dd.

slope number 2:
Image

very smoky, untidy shed after she ran this morning:
Image
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
dollydog
Yeah Man, the Interstate
Posts: 532
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: gt250 reed valve engine

Post by dollydog »

after several weeks of bad luck, including locking the engine up and it stopping dead, from about 3000 revs to 0 in a millisecond, i'm finally up and running again. this time properly.
[a], the tab on the tab washer on the crank nut broke off and the cranknut undid itself until it reached the clutch basket, then it stopped dead.
, sorted that out and unfortunately i could never get it to run quite right after that. whether it twisted the crank slightly, i haven't checked yet.
[c], rebuilt another bottom end. different crank, new seals. it would only run on the right pot. it would not run on the left. changed the reeds over left to right, no difference. rebuilt another left carb, no difference. tried new b6, b7, b8 plugs, ditto.
[d], rebuilt another bottom end, different crank, this time with 16mm gudge pin little ends [more on that later], changed all the reed valve gaskets, and smeared them with 3 bond. stripped the carbs again and rebuilt them. new piston rings, no difference.
[e], by now getting mightily miffed, so treated myself to a pair of microns and fitted them. no difference. then i happened to notice a piece of insulation missing off the electronic ignition pick-up. the ignition timing must have been all over the place. bought a new pick-up and fitted that, timed it up to the standard marks on the rotor, and away she went - both cylinders.
[f], with the rotor on, the missing piece couldn't be seen [well apart from the fact it wasn't there], and believe you me, there's a hundred other things i've missed out of this post with other things i tried. otherwise it would have been about 6 pages long.
[g], with standard gt250 carb settings, standard jets, etc, which i will change in due course, flick the choke on, kick her over, switch ignition on, kick her over again and away she goes, every time. now she's starting and running ok like my gt250's do, i'm buying a set of rd250 piston kits for her. the windowed ones - which is why i went to 16mm gudge pins. then i can start setting the carbs up properly :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
dollydog
Yeah Man, the Interstate
Posts: 532
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: gt250 reed valve engine

Post by dollydog »

sorry no updates for a while, but really busy tbh. anyway, this is how my monoshock reed valve ramair gt250 sits as of today. several bits off for powdercoating and fuel tank/sidepanels getting ready for paint. if i get chance later i'll post some inbetween photo's of all the work i've done on her :D
cheers, dd.

reedy gt250:
Image
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
User avatar
Alan H
Moto GP
Posts: 2561
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 2 x GT550s GT750B, GS750B
Location: The Republic of South Yorkshire

Re: gt250 reed valve engine

Post by Alan H »

Saw it in the 'flesh' yesterday and it just shows what sort of thing can be achieved in a shed - as with your other projects, of course.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
dollydog
Yeah Man, the Interstate
Posts: 532
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: gt250 reed valve engine

Post by dollydog »

thanks alan, one tries one's best :o you really don't want to know what garry double r has just offered me for a project, you really don't. anyway, here's a few more piccies of the reed valve build :D
cheers, dd.

reedy1:
Image

reedy2:
Image

reedy3:
Image

reedy4:
Image

reedy5:
Image

reedy6:
Image
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
User avatar
Alan H
Moto GP
Posts: 2561
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 2 x GT550s GT750B, GS750B
Location: The Republic of South Yorkshire

Re: gt250 reed valve engine

Post by Alan H »

Seen it. Gawd knows where you'll put it or what Deb will say.....
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Post Reply