Topics

mate is having tremendous problems with the wiring on his air cooled rd250. with a new 5 wire reg/rec on it he can work out where those wires go, but what now feeds the green wire that goes to the points? a wiring diagram would be most useful before he drives me mad. many thanks for any help 
cheers, gil.

my old mate phoned me the other day telling me he'd gone to kick his invader - or x5 as you call them - up and on the second kick the engine just locked. told him the usual, take crank plugs out and drain the cranks. take the spark plugs out and should be able to kick it over. no, still locked solid. so, engine out and over here for a stripdown. there was a deep score in the right liner, right where the piston circlip sits, so i thought the circlip had come out and jammed it all up. nothing so simple. after much sweating and cursing getting the barrels and pistons off, the photo shows what i found. a trip over to see uncle ron at fahron is in order. luckily he only lives about 10 miles from me 
cheers, gil.

problem with the invader:

just a quick question. i've got a 250lc top end on my gt250 engine - i wanted a watercooled gt250  will the rd350lc reed block fit into the 250 inlet manifold? the bolt hole distances are the same and my 250 reed block seems to have plenty of wiggle room, both up and down and side to side. just like to know before i order the 350 reed block. what i don't want is to start machining the inlet manifold. all answers gratefully accepted. many thanks.
cheers, gil.

it's marked as MIKUNI KOGYO IM-4. after googling it i found one at an aussie breakers yard, but it just says suzuki or kawasaki, but it doesn't say which model. this came with a load of suzuki t250 bits i bought, but it definitely isn't off a t250. also checked t20 and t200, but they are nothing like 
cheers, gil.

oil pump:

just wondered what paint anybody would recommend for my rd250lc barrels and heads? powdercoated or ceracote or would normal enamel spray be good enough? many thanks 
cheers, gil.

anybody had any jtt piston kits? can't find any info on them, but at the price they are i reckon they are chinese, and if they are i'll give them a miss 
cheers, gil.

just asking, but is there any difference between the sleeve nuts o.d. on the 250 lc and the air cooled model? the air cooled set i have at the mo are near as dammit 12mm o.d. and fitted in the lc head don't seem to be that loose to me, so i'm guessing the proper lc sleeve nuts are the same o.d. as the air cooled ones. just trying to tick boxes off. many thanks for any replies 
cheers, gil.
p.s. the holes in the barrels are far bigger for some reason.

i'm in  the middle of a project to put a rd250lc top end on a gt250 bottom end. obviously i can't use the yamaha water pump etc, and so i need a decent 12v water pump to fit somewhere neatly and discreetly  : there must be others on here that have built specials and had to make do with aftermarket stuff, so what's the best 12v pump to use? ron at fahron recommended a bosch pump, at about £40 - [$55], but i'm blowed if i can find anything to suit. the only ones i can find are either tiny pipework i.e. less than 10mm, or submersible, which are both out of the question. any help gratefully accepted and appreciated 
cheers, gil.

i tried a search, but i ended up with just one page of rd and rdlc info, so not what i was looking for. i'm sure i've seen it on here - or maybe the old site? - but somebody transplanted a rd250 top end onto a suzuki gt250 bottom end. i'd love to be able to find it and see how he went on with it 
cheers, gil.
p.s. i'm thinking of transplanting a rd250lc top end, so i've got a reed valve and water cooled gt250 to go with my reed valved gt250 

i know this is a common problem, but has anybody ever actually completely cured it? i've tried new needles, viton tipped, super unleaded fuel, but they still stick now and again. tap the floatbowl of the carb and watch bubbles go up the fuel pipe towards the tap. the way i thought of fixing it was epoxy a tiny round magnet - the sort i use in my magnetic screwdriver - under the tang of the floats. even though the tang is brass, the magnet is strong enough to pull the spring pin down, so the float needle lifts off its seat. it works without epoxy on it [yet] and even works with the carb upside down. any other solutions out there? 
cheers, gil.

round magnet fitted under tang - an old one:

being as most of you are yamaha officianados, can anybody tell me if banshee reeds are the same size as normal rd350lc reeds, please 
cheers, gil.
p.s. i've got normal rd350lc reeds in my suzuki gt reed valve engine. only cheapo ones, but they worked long enough to get the engine running fairly right.

i bought a pair of wiseco gt250 pistons ages ago, but unfortunately they came without rings. standard size [54mm], but the ring lands are exceedingly thin. i tried a 23 thou feeler gauge and that just fits. about 0.58mm in metric. after spending a long time looking through the wiseco catalogue i can't find the rings anywhere. fleabay has the piston kits for 174 ps pistons, but not the rings on their own. any ideas on who could supply me 2 sets please?  :cheesy:
cheers, gil.

i've been trying to explain to a ts125 owner that k&n type filters are no good and he should use a pod/foam type filter instead. can somebody please explain [in layman's terms] the theory behind this? then i can copy and paste it to him. when it comes to setting carbs up i'm not the greatest  ;D
cheers, gil.

ok, i got the reed valve gt250 engine running fine. anyway, to the point where it will start first kick every time. now what, thinks me? i saw this monoshock swingarm off a yam yzf125r and liked the looks of it. first fit i'm very pleased with, but there's a lot of fabbing between now and the finished product. why do i keep doing this to myself?  ;D
cheers, gil.

first fit:

as some of you know, i converted a ramair gt250 to reed valve. after an awful long time trying to get it running again on both pots, i found the pick-up on my electronic ignition had a piece of plastic missing off the face, which put the timing all over the place. anyway, now sorted. so i saw a pair of micron power exhausts for a nice price and bought them. engine sounds lovely with them fitted, but i'm only blipping the throttle to about 4000 revs. when i was doing all the messing about i put the carbs back to standard, and i'm obviously going to have to change them, once the main jets come in they're going to be a tad small. any ideas on the jetting? atm i'm on 28mm mikunis, #30 pilot jets and 112.5 main jets. needle is on the middle notch. any advice would be greatly appreciated  ;D
cheers, gil.
p.s. looking at the plugs after a 5 minute warm up they look fine.

my mate wanted his dt125 dated. he's had it years, bought it for £10 from an old train works and never bothered to check up the registration  to register it. now he's refurbing it and wants to know what year it is, so he can order the decals for it. i looked on here: https://www.motorcyclespareparts.eu/en/yamaha-parts/yamaha-model-prefix-motorcycles-1970-1994 annd guess what? it's not on there. i reckon it's 74 or 75, but if anybody knows for sure please let me know. frame number is 1G0 - 311*** engine number begins *100* - 311***. i'm at a loss  ;D
cheers, gil.

in my infinite wisdom [or stupidity] i came across a good condition tyz250 engine, all complete except the carb. having mikuni vm carbs coming out my ears  ;D i wondered if anybody knew the standard jets for this engine? or at least somewhere to start?  i've got a vm26 of unknown origin with airscrew one side and tickover the other, which i presumed was off a single? also got vm28's off a gt250a which also fits the rubber carb adaptor. any recommendations which one to use? i'm changing the standard front sprocket for a 14 tooth and it definitely won't be used as a trials engine any more, it's going in a suitable road chassis when i can find one and an adapted rg250 spanny. many thanks.  8)
cheers, gil.

after MUCH googling etc, i cannot find an instance of a modern inline 4 cylinder 2 stroke engine - well not for a bike anyway. apart from mr millyard's welded together crankcases to make his multi's, i'm stumped. i'd love to build a 500cc engine using the gt250's as my base. the crank would be fairly easy, but the crankcases are such a weird shape, getting 2 of them side by side looks virtually impossible. converting an inline 4 cylinder 4 stroke to 2 stroke looks just as difficult. any thoughts/ideas would be welcome. apart from don't do it :D
cheers, gil.

another idea i mooted in my over imaginitive brain was to build a proper [as in ramair] gt250 with electric start. i've still got a spare starter dynamo off my 1965 t10 and that was where the idea came from. surely nobody has done this before? fed up with thinking up projects, only to find somebody has already done it. biggest problem with this will be the end of the crank will need altering and trying to find somewhere to hang that big heavy stator. oh yes, then there's the engine/magneto cover 
cheers, gil.

ok, i'm converting a ramair gt250 to reed valve. after measuring the set-up on an rd250, the way i've made my set-up makes it about 25mm longer than the rd. is this unacceptable? will it sort of work? don't want to go ahead with the welding of the reed cage til i get an idea if it will work or not. any ideas, please reply  ;D
cheers, gil.