Overly Tight Chain

[Paysts]

Hello there. I need an opinion as to what is the deal with the chain on my 85 Honda 250R as it is extremely tight, as in less than 1/2 " of movement from the middle.

I installed a new 86 250R engine into it, but with the previous engine the chain slack was perfect. And I'm a bit embarresed to say this, but I drove it because I've had such an anxiety to ride since it has been over 1 year since the engine died, so when I took it out yesterday, the bolts holding the rear sprocket broke off and the chain slipped off and the sprocket is now dangling on the axle.

I know, I know, I should have adjusted the rear, but I didn't have the tool, and I'm untimately confused as to why the chain was extremely tight now with the new motor when it was perfect with the old motor. Thanks.

[Kintore]

My only suggestion is that maybe there was a 1 tooth bigger sprocket on it, Im not sure wether or not 86-85 motors had a different sprocket location but I dont think so.

[i58829]

I dont know why it was any tighter with one motor vs. the other unless the newer one had a sprocket thats a tooth bigger. I do know before i was 'knowledgable' about atvs i tightened the chain on my 83 R a little too much and it was putting a lot of stress on the shaft coming out of the case and pushed a little oil. This was just riding it in the yard for a couple minutes. As far as adjusting it goes if its the same as the other atcs all you need is an allen wrench to loosen the two bolts on the back of the swingarm and big pair of adjustable pliers to turn the carrier.

[Huffa]

What Kintore said and the fact that most chains run loose-tight-loose at different spots while rotating the wheel.

Always adjust your chain when it's at the tightest position and when it's clean.

If the sprockets are the same then most likely you just so happened to check the chain at it's tightest position.

Are you aware of how to check for the exact amount of freeplay the machine should have if you don't have a manual?

[Paysts]

Thanks guys.

Let's see, I'm supposed to check the chain at about the mid-point between the gear and the sprocket, and there should be about 1.25" - 1.75", right?

I do have the manual, some .pdf from Honda that I found here on this sight (this place is infinitely useful).

Looks like I will be checking the gears, anyways, thanks.

[Maico]

With the trike up on a stand and the rear end off the ground...if the chain runs loose-tight-loose...your chain is stretched unevenly and your sprockets are worn un-even too. Replace them both. When the suspension travels thru it's arc, the chain will be tight at 1 point. That's where you should measure slack and adjust accordingly.

[Dirtcrasher]

You better hope you didn't damage that countershaft bearing....