RE: Engine piston wont cycle
 

no its not fixed yet, after looking at the rod, it appears that it may be longer, also the the pistion ring was broken off too..that may be the problem?

RE: Engine piston wont cycle
 

The longer rod would definitly be the problem. The broken ring is not good either. Do you know how the ring got broken? Is it possible that you accidently broke it during installation, or did it break while the engine was running? That could be a whole different issue.

RE: Engine piston wont cycle
 

I bet you ended up with the rod for the G-90. This is the one you need.

http://www.supertigre.com/parts/xr11003570.html

RE: Engine piston wont cycle
 

ok so i figured out that the orginal connecting rod is shorter than the new one from tower hobbies and it is the one for the S75/G75, problem is i dont know what size the orginal rod is, tower customer service said it must be an older model G75 but its not a old model at all. its the same casing as the current models...help

RE: Engine piston wont cycle
 

When you put the new rod in it probably let the ring come up above the sleeve when the head was off. Then when it went back down it snagged and snapped. You need to go to the Tiger forum I mentioned in an earlier post and talk to BAX there. He is associated with the Manufacturer as a rep and with Tower as well. He can help you straighten this out. Stop talking to clerks on the phone. They try and they are sincere but they can't always do the job.

RE: Engine piston wont cycle
 

If you have a SuperTigre G-75 that's been purchased in the past few years, the connecting rod for the S-75/G-75 is the correct one, and the one from your engine should be identical. It is possible, however, that if the rod you recently received is longer than the one you took out of the engine, you got a package with the wrong rod in it. We'd need to see it to be sure.

If you do have the correct rod, then we'd not know what would cause your engine to jam at Top Dead Center, unless there's some debris or the ring is catching a port.

RE: Engine piston wont cycle
 

Do you still have the orig rod to compare against or is it gone?

RE: Engine piston wont cycle
 

yeah i'll take a pic so u can see

RE: Engine piston wont cycle
 

Ok so here is the pics of the connectin rods..

RE: Engine piston wont cycle
 

Hello! ;)

RE: Engine piston wont cycle
 

hey i wonder what size or type of rod this is?

RE: Engine piston wont cycle
 

Just a guess from the photo but the G-90 would be my guess.;) Talk about apples and oranges!:eek: Any idea at all what the label said?? Maybe it was just marked wrong or you didn't notice it was the wrong part? It happens.

RE: Engine piston wont cycle
 

yeah the label stated it was a connecting rod for a S75/G75...i dont know what to do lol

RE: Engine piston wont cycle
 

Whenever I need an engine part I contact Bob's Engines. He has loads of new and used parts and used engines for salvage items.

Bob Boumstein

mailto:[email protected]

402-334-0122 [evenings 7:00PM to 9:00PM, Nebraska]

RE: Engine piston wont cycle
 

I'm not saying this is the case with ST, but some engines come with a liner shim. If the shim gets left out of the reassembly, then that will cause the piston to come up higher in the liner.

RE: Engine piston wont cycle
 

There is an obvious difference in length. That rod will NEVER fit![:@]

RE: Engine piston wont cycle
 

Look at the photo again. I don't fool with the STs often but I do have the break down charts out in my shop. I will check them out today and see if there is a shim under the sleeve but I don't think so? Those are just two very different rods!

RE: Engine piston wont cycle
 

If the new rod was marked for the .75, then it's likely a wrong rod was packaged for you. Contact the seller. They should be able to work out an exchange and get you the correct rod.

RE: Engine piston wont cycle
 

OK! so apparently there was a production problem in which many of the rods did not fit properly, they said there were going to pull many rods from there ware house ans compare for quality control, and they are shipping mr a new rod free of charge! woot!

RE: Engine piston wont cycle
 

Great! :)Hopefully a correct one.[X(]:eek:

RE: Engine piston wont cycle
 

If the length of the rod was indeed a CQ issue, they have some serious problems. lol

RE: Engine piston wont cycle
 

Nah, just a packaging error. Cheap labor strikes again. You get what you pay for in labor. Then again, if you hand a guy a pile of parts and tell them to stick them in "these" bags and put "these" labels on them, who do you blame then? Where does the buck stop? At YOU, when you should have noticed the rod was obviously too long before even trying to install it.

RE: Engine piston wont cycle
 

generally, the backplate being on wrong causes the crank to stop on the down stroke, it actually makes the piston skirt hit the backplate, that is why some are machined for piston skirt clearence. If you remove the head and back plate, rotate the assembly and there is no lock up, then install the back plate and try it again, if it still rotates fine, then your problem is lack of head shims or the rod is the wrong one. The only thing you changed was the rod and as long as everything else was put back together the way it came apart, then the rod is wrong. I would almost bet the design changes between the g-75 and sk-75 included a different rod, this is more than likly a wrong part issue than a internal issue else where. If you want to verify it, remove the new rod and line them up one on top of the other, they should be identical except for the defect in the old rod, any slight difference resulting in a longer rod will be an issue.

RE: Engine piston wont cycle
 

No bruce, it was a factory error in which it was made incorrectly, not packaged wrong... and if you first look at them you can not tell a difference esp when the engine is in parts...problem is fixed this thread is over

RE: Engine piston wont cycle
 

Thats very, very rude! Guys like Bruce and others here work their butts off to try and help us beginners and you say he, and some of others are wrong and yet you never say thank you in return? Thread is over? How arrogant of you!

Welcome to reality. That new rod is much longer than the one you removed. That's very obvious. Thats not a quality mistake by the machinist and/or the shipping dept. You ordered the wrong part.