Topic: gt500 2 stroke

[mk0094@hotmail.com]

can anyone tell me if this was a good buy? i just picked it up from the bone yard. it has a custom baby blue metalic paint job on the fenders, and tank, the fram is a little rusty, but might clean up well. it is not running, but i have not looked at it yet. i was told that it was a wiring problem (which is alwasys fun to track down). the seat is re-covered.

it didnt have an airbox or batt. so i bought them today on ebay since the junyard did not have any. i was told that it is a pretty hard to find bike and may be worth a bit, but i am a little skeptical about it.
 
i thought it was too good to pass up, so i snagged it and i am hoping to flip it soon, since i need money for tuition more that a sweet 2-stroker. let me know what you think, ill get some pics tomarow. it ahs a clear ohio title and key and all. paid 450 for it, so it was not a bad deal i dont think.

[bill440cars]

           mk, the big thing on all the 2 strokes is the crankshaft seals. Two cylinder and three cylinder models can be a bit pricey, if the seals are bad. If they sit for a long period of time, they tend to dry out and get hard. I don't know any other way to check them myself, except to try to get it running and be prepared to shut it own because they tend to run away  and they also foul the plugs badly. If you can get it into shape, it can be a good runner though. Got any pictures? What year model is it? There were at least 2 variations of it and the first (called the COBRA) one is pretty collectible.

                                                             Later on, Bill

[crazypj]

The twins are not too difficult to fix, the crank comes apart pretty easy and is OK to true up again.
The triples are a lot more involved, I haven't done a 3 cyl for years. ( but I do have a set of NOS rods for GT750 if anyone needs them )
You could make a really wicked cafe racer, shop I used to work for had one in IOM TT and came 8th (production TT, LOOOOOONG time ago, about 1972)
PJ

[bill440cars]

The twins are not too difficult to fix, the crank comes apart pretty easy and is OK to true up again.
The triples are a lot more involved, I haven't done a 3 cyl for years. ( but I do have a set of NOS rods for GT750 if anyone needs them )
You could make a really wicked cafe racer, shop I used to work for had one in IOM TT and came 8th (production TT, LOOOOOONG time ago, about 1972)
PJ

           Careful there PJ, you're liable to start giving away your age there.    PJ, You ever done crankshaft seals on an RD350? If so, got any tips? 

                                                     Later on, Bill

[RRRToolSolutions]

I wish I had one. Those are great old bikes and make great restoration projects. Don't worry - there are more parts in the cyclinder head of a CB750 than in the entire engine of a 2 stroke. Here is a pic of my H2 triple I did about 2 years ago. Seriously, these things are so simple to rebuild and are a blast to ride. Enjoy it and let us see pics of the progress.

Regards,
Gordon

 

[mk0094@hotmail.com]

ok, it is a 76, it has compression, clean carbs (as of today). i am a little concerned because i do not have a spark, but the rest of the electrical is working fine, so it might be a grounded wire or something.

i have a small prob. the gas tank key does not work right. it seems that the locking mech. is jammed or something. also, the tripple tree lock does not work, leading me to believe that it is not the stock ig. (plus the key says it fits honda, so that is a bit of a give away). so now i just got to figure out how to open the gas tank, get spark and i am going to list ot on ebay.

the vin # starts w/ t500-xxxxxx so does taht make it a t500 or like the side covers say a gt 500?

also, i am not familiar with the oil injection. it has 2 out tubes from what looks like a pump, one goes lower, i assume to hit the crank case and moving parts out of the cyl. and one goes a bit higher, not a lot higher, but looks like it may hit the piston, but i am not sure, any help on that is appreciated. there are 2 tubes on each cyl. side.

other than that, that is where i am at today after 3 hrs of tinkering. thanks for the help guys and gals.

[bwaller]

Just a few years back guys were picking these up to go vintage roadracing, there is loads of power to be unleashed! They are a bulletproof old two stroke and plenty of sites out there with info on how to make them competitive.

It shouldn't be too tough for you to sell. Good luck.

[crazypj]

The twins are not too difficult to fix, the crank comes apart pretty easy and is OK to true up again.
The triples are a lot more involved, I haven't done a 3 cyl for years. ( but I do have a set of NOS rods for GT750 if anyone needs them )
You could make a really wicked cafe racer, shop I used to work for had one in IOM TT and came 8th (production TT, LOOOOOONG time ago, about 1972)
PJ

           Careful there PJ, you're liable to start giving away your age there.    PJ, You ever done crankshaft seals on an RD350? If so, got any tips? 

                                                     Later on, Bill

From what I remember they have a labyrinth seal on centre instead of rubber oil seals, which makes life a bit easier unless the bearings have failed.
It should be pretty easy to get parts as the crank is (I think) the same as a Banshee, check out Banshee sites.
If you check the XS650 Garage there is a guy doing a 277 re-phase on XS650, posting a bunch of pics
http://xs650temp.proboards29.com/index.cgi?board=EngineModified&action=display&thread=1167455228
I'll try and find the Alpha Bearings information  I downloaded a couple of years ago, was mirrored on an Australian site, the British original wasn't working last time I tried.
PJ

The TT thing was a few years before I worked there.

[crazypj]

 

the vin # starts w/ t500-xxxxxx so does taht make it a t500 or like the side covers say a gt 500?
Probably fine, just changed Gas tank and fitted disc brakes from what I remember.

also, i am not familiar with the oil injection. it has 2 out tubes from what looks like a pump, one goes lower, i assume to hit the crank case and moving parts out of the cyl. and one goes a bit higher, not a lot higher, but looks like it may hit the piston, but i am not sure, any help on that is appreciated. there are 2 tubes on each cyl. side.
Crank case/cylinder (oil) injection or CCI one line will lube main bearings other goes to intakes
PJ

other than that, that is where i am at today after 3 hrs of tinkering. thanks for the help guys and gals.

[bill440cars]

The twins are not too difficult to fix, the crank comes apart pretty easy and is OK to true up again.
The triples are a lot more involved, I haven't done a 3 cyl for years. ( but I do have a set of NOS rods for GT750 if anyone needs them )
You could make a really wicked cafe racer, shop I used to work for had one in IOM TT and came 8th (production TT, LOOOOOONG time ago, about 1972)
PJ

           Careful there PJ, you're liable to start giving away your age there.    PJ, You ever done crankshaft seals on an RD350? If so, got any tips? 

                                                     Later on, Bill

From what I remember they have a labyrinth seal on centre instead of rubber oil seals, which makes life a bit easier unless the bearings have failed.
It should be pretty easy to get parts as the crank is (I think) the same as a Banshee, check out Banshee sites.
If you check the XS650 Garage there is a guy doing a 277 re-phase on XS650, posting a bunch of pics
http://xs650temp.proboards29.com/index.cgi?board=EngineModified&action=display&thread=1167455228
I'll try and find the Alpha Bearings information  I downloaded a couple of years ago, was mirrored on an Australian site, the British original wasn't working last time I tried.
PJ

The TT thing was a few years before I worked there.

        Hey thanks for the assist there PJ. Nice save on the TT thing.   Later on, Bill

[malcolmgb]

a mate of mine has had a GT500 from new in 1978, I have a PDF of the parts manual if it is help to you.
He has had very few problems with it, never had the bottom end apart, he has replaced 1 cylinder head because of cracking and I think he had to replace or repair something on the magneto or cdi unit.
It was a choice between the GT500 or CB400f when he bought it. 

[mk0094@hotmail.com]

malcombgt,

if you got a copy of the manual, i would love to check it out, the email is
mk0094@hotmail.com
if you get a chance. also, anyone in ohio that is looking for a gt 500 let me know, maybee we can work something out before it hits ebay.

mike

[Dave L]

Hi
The 500 twin was a very good bike with a lot of grunt off the line , and was one of the most durable two strokes
of its time and had some very good test reports in motocyclist magazine many years ago ive still got these mags fom 1973

Here in the uk there are still a few good ones about ,but one of the hardest parts to get is the kick start pawl it seems these
can crack , so do not give it a hard time ,get all the other things sorted first prior to trying to start it up. there has been lots if rebuild articals in clasic motorcycle mechanics magazine  last year.

Once you have got it on the road you will find its a very nice bike indeed .

regards Dave L
UK

[crazypj]

Usually the kickstart breaks because its allowed to slap back to the upright position and then jabbing at kickstart as if its a 125 MX bike ( people afraid of kickback)
The cylinder heads crack from the spark plug hole to one of the cylinder head bolts due to plugs being overtorqued, I'm pretty certain there is a Suzuki bulletin about it (from 1970 ish )
I'm pretty sure the GT500 was at least £200.00 cheaper than 400f
PJ

[malcolmgb]

malcombgt,

if you got a copy of the manual, i would love to check it out, the email is
mk0094@hotmail.com
if you get a chance. also, anyone in ohio that is looking for a gt 500 let me know, maybee we can work something out before it hits ebay.

mike

I have e-mailed it to you, It's a large file, any problems let me know.

[malcolmgb]

Usually the kickstart breaks because its allowed to slap back to the upright position and then jabbing at kickstart as if its a 125 MX bike ( people afraid of kickback)
The cylinder heads crack from the spark plug hole to one of the cylinder head bolts due to plugs being overtorqued, I'm pretty certain there is a Suzuki bulletin about it (from 1970 ish )
I'm pretty sure the GT500 was at least £200.00 cheaper than 400f
PJ

hi pj

spoke to my mate, he says it always seems to be the L/H cylinder heads which crack. He remembers his GT500 was about £700, do you remember how much the 400/4 was.

[mk0094@hotmail.com]

thnaks for all the help this far. here is where i am at. the carbs are clean, so is the petcok. the carbs fill w/ gas. i had spark, but now it is intermitent, and will spark a little now and then when kicked in the off position of the kill switch. so i have a wire that is rubbing somewhere,

plan of action:
jump the cdi to the coil directly and check spark. if it works, then the problem is in the kill switch or ig. switch.

if no spark, then it is in the wires from the alternator to the cdi.

im going to mess with it tomarow. like i said, anyone in ohio that wants a gt 500 titan, let me know, we might work something out before i put it on ebay this weekend.

mike