14 replies to this topic

[Motorrad]

Just picked up a new to me 05 Gas Gas TXT Pro 300... Few questions...
I just noticed it has a blown base gasket (cyl base) on the left side... Is this common? its a VERY low milage bike still has original tires on it with decent tread left.

what is involved in changing the base gasket? same as any other 2 stroke, or are there extra parts etc in there?
Does the CD that comes with the bike have torque specs (dont have it with me right now or id check) if not where to I obtain torque specs for the bike (cyl nuts etc)..

thanks guys
-Dave

[MIKEE]

If your just going to the base gasket then you will not need to undo the head bolts, just the four bolts around the base of the cylinder.
Then you can lift the barrel off and fit a new base gasket.


Yes the CD if of help ut i don't think it has all the torque setting on it..

[Motorrad]

Just gave "hard rock trials" a call in AZ. They say its the first one they ever heard of doing this... and is very insistant that I check the trueness of the gasket surface.....

He also asked me which gasket I have in the bike... It should be stock, but he said there are several various choices?

Can somone fill me in on the choices? what stock is etc....
I understand that they are different thicknesses and pretty much just reduce the compression resulting in different power feels.... I dont mind the power... stock or alittle more than stock wouldnt bother me, I come from a world of open class desert racing etc so handling power isnt the issue...
My only concearn is if stock or alittle thinner than stock will still run fine on California 91Octane pump fuel.. since Im not feeding it race fuel.. $4.50 plus a gal is enough for me right now...

[EdHolland]

Hello Dave,

I had the same question a while back and found this list posted bij Jon (JSE) this was for a 2004 TXT Pro 300. Maybe ask Jon first if the 2005 model uses the same torque specs.



Foot pounds /Newton Meters

Front Wheel Axle_______________ 30 to 37/ 40 to 50
Chassis to swingarm fastener_____ 44 to 52/ 60 to 70
Upper shock absorber fastener____ 30 to 37/ 40 to 50
Lower shock absorber fastener____ 30 to 37/ 40 to 50
Handlebars___________________ 13 to 18 /18 to 25
Hand levers___________________ 5 to 7 /7 to 10
Radiator fasteners______________ 13 to 18 /7 to 10
Front bridge wing_______________ 5 to 7 /7 to 10
Brake pedal___________________ 20 to 24 /27 to 32
Muffler fasteners_______________ 13 to 18 /18 to 25
Rear wheel axle________________ 30 to 37 /40 to 50
Rear brake caliper fastener_______ 20 to 24 /27 to 32
Front brake caliper fastener_______ 20 to 24 /27 to 32
Exhaust pipe elbow fastener______ 20 to 24 /27 to 32
Engine fasteners________________ 13 to 18 /18 to 25
Rear brake pump fastener________ 5 to 7 /7 to 10
Spark plug_____________________ 8 to 9 /11 to 12
Ignition fasteners_______________ 5 to 7/ 7 to 8
Clutch fasteners________________ 5 to 7 /7 to 8
Cylinder stud bolt fasteners_______ 18 to 20 /25 to 26
Reed fasteners_________________ 5 to 7/ 7 to 8
Clutch ground fastener___________ 2 to 3 /3 to 4
Crankcases fasteners____________ 5 to 6 /7 to 8
Water pump cap fastener_________ 5 to 6 /7 to 8
Clutch cap fasteners_____________ 5 to 6 /7 to 8
Flywheel fastener_______________ 30 to 32 /40 to 42
Water fastener_________________ 7 to 8 /10 to 12
Ignition cap___________________ 5 to 6 /7 to 8
Engine drain plug_______________ 9 to 10 /12 to 14
Kickstart pedal screw____________ 9 to 10 /12 to 14
Shift pedal screw_______________ 5 to 6 /7 to 8
Cylinder head screws____________ 8 to 10 /11 to 14
Cylinder nut___________________ 18 to 20 /25 to 27


Cheers,

Ed

[JSE]

EdHolland, on Jun 17 2008, 12:53 AM, said:

Hello Dave,

I had the same question a while back and found this list posted by Jon (JSE) this was for a 2004 TXT Pro 300. Maybe ask Jon first if the 2005 model uses the same torque specs.



Foot pounds /Newton Meters

Front Wheel Axle_______________ 30 to 37/ 40 to 50
Chassis to swingarm fastener_____ 44 to 52/ 60 to 70
Upper shock absorber fastener____ 30 to 37/ 40 to 50
Lower shock absorber fastener____ 30 to 37/ 40 to 50
Handlebars___________________ 13 to 18 /18 to 25
Hand levers___________________ 5 to 7 /7 to 10
Radiator fasteners______________ 13 to 18 /7 to 10
Front bridge wing_______________ 5 to 7 /7 to 10
Brake pedal___________________ 20 to 24 /27 to 32
Muffler fasteners_______________ 13 to 18 /18 to 25
Rear wheel axle________________ 30 to 37 /40 to 50
Rear brake caliper fastener_______ 20 to 24 /27 to 32
Front brake caliper fastener_______ 20 to 24 /27 to 32
Exhaust pipe elbow fastener______ 20 to 24 /27 to 32
Engine fasteners________________ 13 to 18 /18 to 25
Rear brake pump fastener________ 5 to 7 /7 to 10
Spark plug_____________________ 8 to 9 /11 to 12
Ignition fasteners_______________ 5 to 7/ 7 to 8
Clutch fasteners________________ 5 to 7 /7 to 8
Cylinder stud bolt fasteners_______ 18 to 20 /25 to 26
Reed fasteners_________________ 5 to 7/ 7 to 8
Clutch ground fastener___________ 2 to 3 /3 to 4
Crankcases fasteners____________ 5 to 6 /7 to 8
Water pump cap fastener_________ 5 to 6 /7 to 8
Clutch cap fasteners_____________ 5 to 6 /7 to 8
Flywheel fastener_______________ 30 to 32 /40 to 42
Water fastener_________________ 7 to 8 /10 to 12
Ignition cap___________________ 5 to 6 /7 to 8
Engine drain plug_______________ 9 to 10 /12 to 14
Kickstart pedal screw____________ 9 to 10 /12 to 14
Shift pedal screw_______________ 5 to 6 /7 to 8
Cylinder head screws____________ 8 to 10 /11 to 14
Cylinder nut___________________ 18 to 20 /25 to 27


Cheers,

Ed

Hi again, Ed!
I'm posting this from my hotel room in sunny Silicon Valley in Northern California where gas is over a buck a gallon higher than where I live (and still cheaper than a lot of places overseas). Those spec.'s should work for the 05' also as far as I can figure. The reason Dave was asked what gasket he had was that the thickness of the base gasket "set' is what determines the squish clearance when hand assembled at the factory.

Dave, measure the thickness of the old base gasket set (it usually is more than one) and then add, say, .1mm for compression and order the number of gaskets that add up to that measurement. I think they come in .3, .8, and 1.0mm sizes so you will "mix and match" them to get close (over the measurement is better than under) and that should work

Cheers.
Jon

Edited by JSE, 17 June 2008 - 07:29 AM.

[JanDyb]

JSE, on Jun 17 2008, 09:29 AM, said:

Hi again, Ed!
I'm posting this from my hotel room in sunny Silicon Valley in Northern California where gas is over a buck a gallon higher than where I live (and still cheaper than a lot of places overseas). Those spec.'s should work for the 05' also as far as I can figure. The reason Dave was asked what gasket he had was that the thickness of the base gasket "set' is what determines the squish clearance when hand assembled at the factory.

Dave, measure the thickness of the old base gasket set (it usually is more than one) and then add, say, .1mm for compression and order the number of gaskets that add up to that measurement. I think they come in .3, .8, and 1.0mm sizes so you will "mix and match" them to get close (over the measurement is better than under) and that should work

Cheers.
Jon

Hehe.. The price of Gas can be discussed alot I think :-) See the americans complain. Dont know how to compare but I was in UK yesterday and payed £1.20 pr liter. Where I live i Norway it is close to 14 kroner = about £1,40 pr liter. Last year I visited Turkey. There it was about £1,50/liter. And that is a "low cost" contry with very low vages!!

To the question wich is in the same way as this topic: Yesterday I got a replacement cylinder from www.trialendurodirect.com . I guess this replacement cylinder does not have the same measures as the original. How can I determine what thickness of gaskets to use?

-Jan

[JSE]

JanDyb, on Jun 17 2008, 02:57 AM, said:

Hehe.. The price of Gas can be discussed alot I think :-) See the americans complain. Dont know how to compare but I was in UK yesterday and payed £1.20 pr liter. Where I live i Norway it is close to 14 kroner = about £1,40 pr liter. Last year I visited Turkey. There it was about £1,50/liter. And that is a "low cost" contry with very low vages!!

To the question wich is in the same way as this topic: Yesterday I got a replacement cylinder from www.trialendurodirect.com . I guess this replacement cylinder does not have the same measures as the original. How can I determine what thickness of gaskets to use?

-Jan

Hi Jan,
Yea, we like to complain about just about everything, I think it's one of our "National Sports". I'll be back in Germany in October so it will be interesting to see how the fuel prices have changed from when I was there the year before last. My guess is that the Yanks who complain the most are probably the least traveled?

The new cylinder may have a different "deck height" than your old one so what I'd do is start with maybe a 1.0mm gasket, put the cylinder on, torque two opposite base stud nuts down, put the head on with three or four capscrews and torque that down and then use two pieces of soft solder put inside the sparkplug hole (curved to contact the front and back of the cylinder wall), turn the engine over with a socket on the flywheel bolt (don't use kickstart lever) remove the solder and measure the thickness of the squished ends to get an accurate measurement of the "squish clearance". Some mechanics like to use clay but I've found that clay is good for finding combustion chamber profiles but not very accurate for squish clearance measurement as the plasticity can throw off the results, especially if the piston crown is dirty or a releasing agent was not used.

You'll want to have the squish clearance in the neighborhood of 1.0mm (.039") so then you'll know what thickness of gaskets to add or subtract to get the correct clearance.

Jon

[EdHolland]

Quote

I'll be back in Germany in October

Like Jan said you will pay 1.40 euro a liter in most countries overhere in Europe. October in Germany ...... Octoberfest Jon ?

[JanDyb]

JSE, on Jun 17 2008, 05:46 PM, said:

Hi Jan,
Yea, we like to complain about just about everything, I think it's one of our "National Sports". I'll be back in Germany in October so it will be interesting to see how the fuel prices have changed from when I was there the year before last. My guess is that the Yanks who complain the most are probably the least traveled?

The new cylinder may have a different "deck height" than your old one so what I'd do is start with maybe a 1.0mm gasket, put the cylinder on, torque two opposite base stud nuts down, put the head on with three or four capscrews and torque that down and then use two pieces of soft solder put inside the sparkplug hole (curved to contact the front and back of the cylinder wall), turn the engine over with a socket on the flywheel bolt (don't use kickstart lever) remove the solder and measure the thickness of the squished ends to get an accurate measurement of the "squish clearance". Some mechanics like to use clay but I've found that clay is good for finding combustion chamber profiles but not very accurate for squish clearance measurement as the plasticity can throw off the results, especially if the piston crown is dirty or a releasing agent was not used.

You'll want to have the squish clearance in the neighborhood of 1.0mm (.039") so then you'll know what thickness of gaskets to add or subtract to get the correct clearance.

Jon

Thank you

I didn`t have the needed equipment so I tried out with the thickest gasket in the gasket package. It seems to work OK. At least no strange sounds.. :-)

The next question is what now? Does it require a break in period? In that case how?

What I have done is to mix 2% oil in the fuel (normally use 1,5%).

Thanks

Sorry if it seems that I have "taken over" this topic, but I feel that this probably also have interest for the original poster.

-Jan

[Motorrad]

Fine with me I dont see it as "taking over".. just adding to....

Anyone know what the easyest way to get all the coolent out of the motor is? the WP is the lowest point, do you remove the entire pump (3 allen screws) or the center tork's screw (brass colored)....

I tryed removing the 3 allens but the pump doesnt seem to want to pull out of the case for some reason..

thanks for the help guys. my manuals are on the way to the house...

JanDyb, on Jun 17 2008, 12:56 PM, said:

Thank you

I didn`t have the needed equipment so I tried out with the thickest gasket in the gasket package. It seems to work OK. At least no strange sounds.. :-)

The next question is what now? Does it require a break in period? In that case how?

What I have done is to mix 2% oil in the fuel (normally use 1,5%).

Thanks

Sorry if it seems that I have "taken over" this topic, but I feel that this probably also have interest for the original poster.

-Jan

Edited by Motorrad, 17 June 2008 - 08:55 PM.

[JanDyb]

Motorrad, on Jun 17 2008, 10:54 PM, said:

Fine with me I dont see it as "taking over".. just adding to....

Anyone know what the easyest way to get all the coolent out of the motor is? the WP is the lowest point, do you remove the entire pump (3 allen screws) or the center tork's screw (brass colored)....

I tryed removing the 3 allens but the pump doesnt seem to want to pull out of the case for some reason..

thanks for the help guys. my manuals are on the way to the house...

The centre torx screw is the one to use if you want to drain the system. Watch out so you don`t loose the washers. There is one nylon washer to seal the WP house and there is a brass washer between the brass screw and the pump impeller inside the housing. If it dont follow the screw and you dont see it inside you have to loosen the housing and try to "lure" (?) it out some way. That is if it is still there of course.. :-)

If You need to take out the WP housing, remove the three allen bolts and wiggle and pull until it loosens. It is only held by a O-ring seal. When remounting be sure that the pin on the WP axle is aligned with the slots in the crank axle.

-Jan

[JanDyb]

JanDyb, on Jun 17 2008, 11:07 PM, said:

The centre torx screw is the one to use if you want to drain the system. Watch out so you don`t loose the washers. There is one nylon washer to seal the WP house and there is a brass washer between the brass screw and the pump impeller inside the housing. If it dont follow the screw and you dont see it inside you have to loosen the housing and try to "lure" (?) it out some way. That is if it is still there of course.. :-)

If You need to take out the WP housing, remove the three allen bolts and wiggle and pull until it loosens. It is only held by a O-ring seal. When remounting be sure that the pin on the WP axle is aligned with the slots in the crank axle.

-Jan

Or if the reason for draining is to remove the cylinder, don`t bother the water pump. Just loosen the water hoses and it will drain all right... :-) you will need to remove the hoses anyway.

-Jan

[Motorrad]

Okay... now.. is there a trick to getting the radiator out not involving removing the motor? I was just going to lift the CYL and put on the new gasket, but the area near the exaust hits the bottom of the radiator before the studs are even cleared.... I have fiddled with the radiator but the cross brace in the frame seems to get in the way as well as the exaust section of the cyl....

[JSE]

Motorrad, on Jun 17 2008, 07:29 PM, said:

Okay... now.. is there a trick to getting the radiator out not involving removing the motor? I was just going to lift the CYL and put on the new gasket, but the area near the exaust hits the bottom of the radiator before the studs are even cleared.... I have fiddled with the radiator but the cross brace in the frame seems to get in the way as well as the exaust section of the cyl....

I'm trying to remember but I think taking out the mounting screws allows enough movement of the radiator, when the hoses are taken off. If there is still a problem, take out the front and bottom engine mount bolts and the engine will pivot up by the swingarm mount.

Jan,
Probably the best way to break in a new cylinder is to ride easy sections. The on/off throttle applications will help keep the motor cool. There will be a little blow-by past the rings until they mate with the cylinder wall but if you avoid overheating the engine you'll be in good shape. 1.5 or 2% will work. I run a 70:1 ratio in my engines (50:1 in my air cooled TY) and had never had any lubrication problems with a full-synthetic premix oil.

Jon

Edited by JSE, 18 June 2008 - 12:44 AM.

[JanDyb]

JSE, on Jun 18 2008, 02:43 AM, said:

I'm trying to remember but I think taking out the mounting screws allows enough movement of the radiator, when the hoses are taken off. If there is still a problem, take out the front and bottom engine mount bolts and the engine will pivot up by the swingarm mount.

Jan,
Probably the best way to break in a new cylinder is to ride easy sections. The on/off throttle applications will help keep the motor cool. There will be a little blow-by past the rings until they mate with the cylinder wall but if you avoid overheating the engine you'll be in good shape. 1.5 or 2% will work. I run a 70:1 ratio in my engines (50:1 in my air cooled TY) and had never had any lubrication problems with a full-synthetic premix oil.

Jon

Thanks again Jon. I looked up the manual and it says only "We recommend an 8 hour break in period" just assuming that everyone knows how that is done.

I guess I should be able to answer the radiator question as I have just done it. Not to mention getting it in again last night.. :-)

I removed all the radiator hoses, the exhaust "bend", the "fan module" and of couse the plug. It was still very narrow but I did manage to get it out (and in).

-Jan