Help with a JTR 160, please

Chesterspal

New member
I picked up this 1996 JTR 160 over the weekend to learn to ride trials on and I'm very excited to get going with it. The bike is still in great shape given its age.

Nothing about it is found on the GasGas site. They do not even list a manual section for year 1996. It's as if this bike never existed : (

The closest year manual I found was for the 2002 TXT but I have no idea if I can go by this for what I need to know, so asking here in the hopes someone has some knowledge of this older bike.

1) Which gear/clutch oil is correct? This 2002 book says 10w30 but someone online posted 5w30 non-synthetic. Honda makes both in their 4-stroke line that is safe for clutch plates so I will use that, once I know which.

Also, there are two black plastic caps under the engine poking through the bash plate. I assume one of these is the oil drain and that I need to remove that bash plate to get to them??

2) What is the gas to oil mixture?

3) Is the coolant a 50/50 mix or do I use it straight and how do I know the fill level?

4) There is this small digital device on the center fairing. The two black wires have been cut. Can anyone tell me what this is for and where those wires connect to?

Appreciate any help you can provide. Really in the dark on this one. BTW: If anyone knows of a third party service book that might cover this year please let me know of it.

Thanks,
George
 
I picked up this 1996 JTR 160 over the weekend to learn to ride trials on and I'm very excited to get going with it. The bike is still in great shape given its age.

Nothing about it is found on the GasGas site. They do not even list a manual section for year 1996. It's as if this bike never existed : (

The closest year manual I found was for the 2002 TXT but I have no idea if I can go by this for what I need to know, so asking here in the hopes someone has some knowledge of this older bike.

1) Which gear/clutch oil is correct? This 2002 book says 10w30 but someone online posted 5w30 non-synthetic. Honda makes both in their 4-stroke line that is safe for clutch plates so I will use that, once I know which.

Also, there are two black plastic caps under the engine poking through the bash plate. I assume one of these is the oil drain and that I need to remove that bash plate to get to them??

2) What is the gas to oil mixture?

3) Is the coolant a 50/50 mix or do I use it straight and how do I know the fill level?

4) There is this small digital device on the center fairing. The two black wires have been cut. Can anyone tell me what this is for and where those wires connect to?

Appreciate any help you can provide. Really in the dark on this one. BTW: If anyone knows of a third party service book that might cover this year please let me know of it.

Thanks,
George

1- regular car motor oil 5w30 non-synthetic 650cc. I dont know what these plugs are but the oil drain is on the right side towards the back. You dont need to take the bash plate off it mite be difficult to get back on.
2- 80:1
3- yes 50/50 if you cant get to the radiator cap (not real familiar with that year model, I have a 01 txt 280) you will need to take the tank off and fill it in the radiator just to cover the fins.
4- pic. would help dont know what this is.

you can shoot me a PM if you need any info not a lot of trials guys here

where are you located?

Here is Jim Snell's you tube videos. He was the US importer.
https://www.youtube.com/results?search_query=jim+snell+gas+gas+videos
 
Appreciate the help on this. Many thanks :)

I was looking in the wrong side, perhaps. Is this the oil drain?

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Question: you're saying I do not need to use special clutch oil in this bike as I do with my 4-strokes?

As for the coolant, I have that port exposed but I have no knowledge of how much coolant should be in there. Right now, I see nothing but cannot see in that far.

image.jpg


So I replaced the battery and this digital device now lights up. It appears to be a time and distance meter. I assume those clipped leads were once connected to a magnetic sensor on the front wheel to measure rotation. Make sense?

image.jpg


BTW: I'm in Connecticut.
 
Appreciate the help on this. Many thanks :)

I was looking in the wrong side, perhaps. Is this the oil drain? i dont think that is the oil drain it should be just under the kick lever inside the frame rail

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Question: you're saying I do not need to use special clutch oil in this bike as I do with my 4-strokes?no special oil

As for the coolant, I have that port exposed but I have no knowledge of how much coolant should be in there. Right now, I see nothing but cannot see in that far. fill it to the top just above the fin you can see. if you over fill it it will just puck it out when it gets hot

image.jpg


So I replaced the battery and this digital device now lights up. It appears to be a time and distance meter. I assume those clipped leads were once connected to a magnetic sensor on the front wheel to measure rotation. Make sense? yes

image.jpg


BTW: I'm in Connecticut.

could i see a pic of the hole bike?

https://www.youtube.com/watch?v=SKPCCsKOgr4
 
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Just go to the bike shop and buy some 2 stroke gear oil. Some bikes are sensitive to clutch drag but should be fine. I had a TXT200 '00 and that evolved from the earlier bike. I say evolved but the engine didn't get bigger than 163 I think.

You can run less oil in a trials bike but if you trail ride on it you'd want to run more. Find a decent oil locally and run at thier prescribed level at the lean end. I used to rum 60:1.

You don't need a trip meter, (thats an aftermarket, never seen a std one still working) but do check if your fan is connected.
 
That was the oil drain port in the picture.

I removed the cover to the water pump and drained out the old coolant. No color to it. Looked like plain water. Flushed it a few times with clean water then added fresh 50/50 to just below the overflow tube inside the filler port.

As to the fan. It was running yesterday but idling in my shop it today, was off. The top of the engine was not that hot so I assume that's the reason... but am I correct in my thinking, here.

Question: there are two adjustments on the side of the carb. I assume one is mixture but is the other on the right with the spring the idle adjust for the throttle? Turning it to the left (out) causes the engine to slow but with much roughness.

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Yes that is correct the one with the spring is your Idol. The other is a fuel screw it works opposite of a air screw. Jim snail has an excellent video on how to adjust that dellorto carburetor
 
You asked to see my bike. Here it is. Still working on it so the air box is not on and the fairings are just sitting there.

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I searched since June for an under 200cc trials bike. Never saw a one in a 300mile radius CraigsList search until this one came up on Sunday morning. Posted the night before.

That carb setup video you mentioned is on YouTube, I assume?

So 80:1 or 60:1 mix... Is there a consensus here or it makes little difference for trials?
 
First off that's one sweet bike. Trials bikes are hard to find of any size you'll find that parts are expensive for them. If that rear fender is bolted on you need to unbolt it and replace the bolts with zip ties that way when you flip it and you will it just breaks off if it's bolted the fender will break the one for my 01 cost a$150.

The first link that I sent you to the YouTube videos for Jim Snell has all of his gas gas videos I think it's seven or eight videos down it will say carb setup

90% of trials riders mix 80:1 or 100:1 like F5 said if you plan on riding it on trails you might want to go 60:1 I don't. If you do ride that on trails they do tend to get hammered it is not a dirt bike.
 
You asked to see my bike. Here it is. Still working on it so the air box is not on and the fairings are just sitting there.

image.jpg

Where do you live? Rascal's Cycles used to be the gasgas trails dealer in Massachusetts. I think he is still has a repair shop in the Brimfiled MA area....
 
There is a large brass bolt in the radiator with wires to it. When it gets hot the cct completes and your fan should start.

That looks very similar to my 00 but few frame changes.

In road racing people run lots of oil, like 20:1 of synthetic which is way more than the bottles usually recomend, but better protection and more power from better sealing.

You can't hurt it putting lots of oil in. You own a 20yr old Spanish bike and all the bearings are old. I'll let you decide how much you want to push the envelope of good lubrication.

The big thing is getting the jetting right. On my 200, using NZ gas at close to sea level and 60:1 for Trials use - so many differences, it was pretty stumbly. I found 1 size smaller pilot and 1 smaller main worked wonders. Maybe the previous owner/s has already changed, but surprisingly few do.

I found my Honda dealer stocked dellorto jets as they owned montessa but that was years ago.
The mixture screw is really for how it reacts from closed to just open. In is richer, out leans it but if you are to 3 screws out go size smaller pilot jet.

Oh yeah mine was difficult to operate the choke lever as it was close to frame. Had to poke it fully on, and drilled and fitted a cable tie to make it easy to pull to close.

Always run carb out of gas. Mine would stick the float jet so would start and run for a min then die and need a tap to get it running again. Ahh, dellortos.
 
First off that's one sweet bike. Trials bikes are hard to find of any size you'll find that parts are expensive for them.

Thanks for the kind words. Plenty of similar trials bikes in my area. All the 250cc and higher bikes you could want in Beta, GasGas but nothing lower, until last Sunday, as I said. Also, the vintage twin shocks. Tons of them in great looking shape around here. I own a mint 1986 Honda TLR200 200cc trials bike but it has been a bear to learn on. I find the 4-strokes harder because if the engine braking causing the bike to chug in low gear. You easily lose your balance. It throws me off.

Was suggested I buy a "newer" modern trials bike, less than 200cc, to learn to ride in. So, that was how I came to own this one.

If that rear fender is bolted on you need to unbolt it and replace the bolts with zip ties that way when you flip it and you will it just breaks off if it's bolted the fender will break the one for my 01 cost a$150.

Thanks for the suggestion. I will do so. I'm sure I'll be falling off often enough :)

90% of trials riders mix 80:1 or 100:1 like F5 said if you plan on riding it on trails you might want to go 60:1 I don't. If you do ride that on trails they do tend to get hammered it is not a dirt bike.

This one also has that choke lever way up under the frame with a cable tie attached. Where I live (and can practice a bit in the yard) is around 100' above sea level but where I can legally ride is more like 500 feet higher.

Well, I also own a Honda XR-80R dirt bike so will not be wasting this GasGas for that kind of rough riding. Still a bit confused about this oil mixing. Only owned one two stroke and it was a small scooter.

What is the advantage of altering the ratio? Is it that you have better engine/bearing protection with a lower ratio but the trade off is more smoke out the exhaust, more fouling of the spark plug... what exactly?

Also, are you running E10 gas? I have a simple method to remove the ethanol to obtain pure gas. I do it for my 1965 Triumph. Adding 1 quart of distilled water to a gallon of premium 91-93 octane gas, shaking the crap out if it, then, letting it sit for 12 hours. You can then drain off the ethanol and water leaving just gas. The octane drops 2.5 points so the reason for using premium gas going in. This lets you leave the gas in there all the time with no issues of eating the rubber, the seals, etc. will not gum up over time.

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This is Shell 90.5 octane puregas I made three years ago. Look at the clarity and golden color. This is the way gas used to look. It smells sweet. No harsh alcohol odor to it. This gas will last forever this way.
 
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Where do you live? Rascal's Cycles used to be the gasgas trails dealer in Massachusetts. I think he is still has a repair shop in the Brimfiled MA area....

I'm in Connecticut. Yes, the bike originated from Rascalls back in 1996 according to the paper work I have.
 
There is a large brass bolt in the radiator with wires to it. When it gets hot the cct completes and your fan should start.

On this bike it appears the thermal switch is inline with the return hose from the cylinder head. See picture.

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In road racing people run lots of oil, like 20:1 of synthetic which is way more than the bottles usually recomend, but better protection and more power from better sealing...You can't hurt it putting lots of oil in.

This is something I need to find out. Do not want to damage anything.

Can someone tell me what these adjustments are used for. I assume they affect the front shocks but I do not feel any real difference compressing them at one extreme setting to the other.

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I'd like to add handgrip guards to this bike. Have them on my dirt bike and they have saved me more times than I can count. However, those guards will not work on this bike as the shift/brake mechanisms are in the way.

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Can someone take a picture of what they use on their bike so I can see just how they fit up?
 
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Yes that is your thermostat housing. You can test your fan by unplugging it jumping the two terminals on the wires and starting the bike the fan should run.

Those are your compression and rebound settings. One fork is compression one fork is rebound. Unless you're a high-level Rider you'll feel no difference I was told to just set mine in the middle.

Back to your oil premix you can mix more oil and it does lubricate better and seal the Rings better but there's a point to where you're just throwing money out the window. If it makes you feel more secure makes it 50 to 1 it won't hurt it it would create a mess with this excess oil not being burnt. I have been running mine at 80 to 1 with Amsoil Sabre at 80 to1 for two years with no problems and I do ride mine in the woods at my clubs property

Are you talking about Bark Busters if so I would suggest not putting them on. On a trials bike the likelihood of you breaking your wrist would be real good
 
That's right it was an inline arrangement, it's been a while. We have gas without ethanol available.
If the jetting is close most of the fuel mixture will be burnt. If it is rich combustion won't be complete, extra mixture will be expelled. That mixture contains fuel and oil.

Additionally trials bikes spend a lot of time, I'm going to use the term slightly erroneously 'Off-pipe', so more mixture is wasted than an engine run at speeds closer to optimum, and thus more being short circuited out without being burnt.
Don't lose sleep over it, people get worked up over oil discussions.
 
My friend Chris is spot on - Amsoil Sabre at 80:1 or even 100:1 is an excellent oil and would be my first choice. If you decide to go with a more oil rich mixture like 50:1 or 60:1 Amsoil Dominator or Interceptor might be a better since they have a lower flashpoint. More oil makes an engine run cooler - not a bad thing in and of itself but the engine needs to get hot enough to burn off the excess oil and the temp at which that happens is called flashpoint.
 
So is 'burning off' the oil the most important thing? I have other requirements but ya know.
 
When I drained the gear oil out, it looked a but suspicious. It appeared to be Royal Purple, which is fully synthetic and not to be used in these bikes. So, I compared it to some 5w30 RP I use in my cars.

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As you can see, the RP from my container (on the left) is identical to what came out of this bike.

Honda makes a 5w30 conventional oil without friction modifiers for wet clutches and I plan to pick some up, today.

The fill port on this older bike is on the side above the sight glass. I read where I need to lay the bike in its side to pour in the 650cc (ml) of oil.

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The sight glass is odd in that it is indicating the proper amount of oil is there even though I drained out exactly 650cc. Not sure if this is just a window or if it fills with oil from the bottom and maybe it got turned up and is staying filled?

Anyone ever have these out and know how they work?

The prior owner gave me a small container of Belray two stroke oil. Nothing on there states a mixture. Will look for that Amsoil Sabre when I'm out today.

What do you folks run for tire pressure?
 
The glass is likely dirty. You might get a bit of brake cleaner with long spout for a short directed squirt and drain/evaporate to clean it.

Try 4psi in the back and 5 in the front and experiments from there. Low pressure gauge will give you a better reading than one expected to be accurate at normal pressures.
 
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