68chevyc10355

I have been browsing over some other forums in addition to this one. There seems to be a common theme that nearly all owners of fourwheelers compare fourwheelers to a banshees in the way of horsepower, torque, and drag racing. Multiple times I have seen “imagine what ours would run like if it had 2 cylinders.” To me this seems like they are overlooking many variables because they make it seem like they are going to double their horsepower, or see a huge gain. Another common theme when comparing to a banshee, the four strokes always bring up that fact that they have so much more torque, which is very true. So, its seems to me that if a twin cylinder motor with a certain amount of cc’s is compared to another motor of the same cc’s, that is only a single cylinder, that there wouldn’t be much to gain in the way of drag racing over a short distance. Or another way of thinking about it would be like comparing a 350 shee to a 350r, but I am sticking with the four strokes because that’s what the subject gets brought up about. 1st: I would think that the twin cylinder would have less in the way of low rpm torque, which so happens to be the number one thing that the big bore four stroke brag about over the shee. 2nd: I would think that the motor would be able to achieve a higher rpm due to the shorter stroke, and could possible achieve a higher hp number. But once again this would be moving in the direction of a street bike motor, which is moving in the opposite direction of the low end torque that gets bragged about by them. 3rd: Wouldn’t traction be a little harder to get with the twin because instead of a power stroke every 720 deg of crank rotation, there would be a power stroke every 360 deg of rotation for a four stroke. Also, to leave out of the hole as hard as they do now they would have to be higher into the rpms. So the “power pulses” would be closer together and wouldn’t give the tires as good of a chance to re-grip, because once a tire starts spinning its hard for it to get good traction again. I was hoping that some of the drag racing gurus and guys who know a lot about motors would be able to enlighten me on this subject, and whether or not my thinking is in the right direction. It seems to me that these guys in other forums are basically just trying to make a four stroke version of the shee, but it would be simpilar to just get one because of how much time has been put into these motors.

Look at your downshaft as you pull in on the clutch handle. If this done not move, then your pushrod probably slipped passed your downshaft. Depending on how badly the pushrod is mushroomed you may have to split the cases in order to get it out properly.

Mine sucked in a little bit of dirt and ended up ruining the top end. Which caused the ring to spin on the piston about a week after the dirt got in the carbs. Do a compression test first, but i would still be very tempted to pull the jugs off and inspect everything because you dont know what your starting compression was to relate to. Its is very basic and doesnt take that much time to drain the antifreeze, remove your carbs, head, and the two jugs. I guess it comes down to is 2-4 hours (depending how fast your are) worth $300 for a new top end?

If you were running and out of the blue it wouldnt run right i would check the flywheel. The nut can back out and the flywheel will back out off of crankshaft. This will cause it to get poor spark if any and not run correctly. Very simple to check and eliminate.

Any updates?

When you put it in gear can you hear or feel the tranny go into gear? Have you tried using all of the gears besides just first? Was the tranny apart recently? If it wasnt then you may be able to eliminate shift forks. Also, just below the left carb (as you are sitting down on the seat) you should be able to see the downshaft move as u pull in the clutch handle. When you let out of the handle you should be able to move the downshaft a little bit because there should be free play. Keep us updated.

If it ran fine before the dust and now it runs if you put some gas down the plug holes and it runs the only things i can think of are your jets in your carbs are plugged, a reed is messed up or the crossover tube that goes between the two carbs is missing. The reason it could be running a touch off of what it was before is because the carb is not regulating the fuel to air ratio, thus not running at optimum. A while back i tore my engine apart and forgot to put the crossover tube between the carbs. It is a 3" fuel line that connects between carbs and is inline with the choke. Without this tube fuel will not get into the engine and it will not run correctly. I am not sure why it overheated so badly except maybe it was running lean enough that it overheated. So, check for the crossover tube and clean the carbs. Do you know of anyone who owns a compression tester that you could get access to? you could check with some mechanics and see if you could borrow it for the ten minutes it would take to check your compression. Even if your motor runs fine you may want to check it to see what kind of shape your top end is in.

Just becaust there is fuel coming from the tank doesnt mean that it is getting to the engine. First put mixed fuel down the plug holes and kick it over that will be the easiest. To do a compression test you will need a compression tester, which i assume you do not have, you will pull a spark plug out and screw in the line from the tester. Hold the throttle pinned and kick it over a fast as you can until the needle stops climbing (turn the kill switch off so that you are sure it wont start with the tester in). Tell us the results so we can help you from there.

To eliminate a fuel problem take out both plugs and pour some premixed fuel down the plug holes. If it fires you have a fuel problem. If not do a compression check and hope you didnt ruin the top end.

Yes you need part #26. It holds the downshaft in place. Make sure that when you put this "keeper" on that it doesnt push down too hard on the downshaft. This will not allow the spring to return the downshaft to its original position and it could remain in contact with the pushrod which is being pushed on by the clutches. This contact could cause the pushrod and downshaft to heat up, the pushrod will mushroom, the downshaft will wear, and the pushrod could slide past the downshaft.

I switched the slides and it sure came alive. Thanks for all the help, especially volcrano...I am gonna take ur advice n get different carbs because I dont need one of the slides sticking open and ruining a good top end. Time to put the hurting on some 4 strokes . Thanks once again!

I am not sure why, but my carbs do not have the pins that fits in the slot running down the carb. Just to try to eliminate oil I put some mixed fuel at 40:1 using Amsoil Interceptor with no change. I am going to try changing the slides and will be back shortly. Thanks for all the help this far!

I have ran both Amsoil Saber and Interceptor with identical results, but have never tried Dominator, though I believe it is very similar to Interceptor. I also forgot to add that in the video the throttle is wide open for short bursts and thats how doggy it is.

I am new to the forum and was hoping to get some insight from some of the other members. I have a 1998 Banshee with the following mods: HJR mx hardcore port, cool head with 21cc domes, wiseco prolite pistons, Toomey t6 exhaust, vforce 3 reeds, K&N pods, +4 timing, trued and welded crank, stock carbs with 340 mains, 25 pilots, TORS removed, and clip on the needle on 2nd from the top. The current temperature is about 70 and my elevation is about 900’. The motor has 4-5 hrs on it. both sides carry 145 psi. I run Amsoil Saber mixed 32:1. The motor ran fine for the time that I have on it. Then, after I synced both carbs one of the cables had a twist and when I gave it gas the slide turned. The motor revved for 2-3 seconds until I killed it. Ever since then it smokes way more than it should and barely has enough power to propel itself. It takes 14 minutes for it to go from 6 to 5 psi on a leakdown test. It will not hit powerband and will not even idle. Both cylinders carry 145 psi. I have replaced the base gaskets and also the cool head o-rings and have also tried another set of carbs with no change. The choke tube is in place and the plugs are new. It does not smell like burnt antifreeze though. A video link is posted below. Any suggestions?