Saying Hello...New to Forum...Not New To Wings...

[normlf]

When I said stretch, I wasn't speaking about the belts being significantly slack.....but they were looser than they should have been. Who knows how long they were used.....and besides a very small amount of stretch coupled with a small amount of wear would easily change the the amount of slack. I fully agree that they would be useless over time if they stretched a lot.. All belts that I am aware of stretch and wear over long use.....just put in a set of three matched belts running a big AHU fan...and come back a year later....you'll find them no longer matched....usable, perhaps, and within limits, but tensions will vary slightly....now if there is something materially different about timing belts.....maybe they don't. If that be the case, I'd appreciate knowing more....I am not an expert and could easily be wrong....but operating on some experience and also some history with mechanical things in general..... I'd bet that some stretching, though small, would occur over time...and with this one it could be a very long time....and loads of miles....just no way to know. In any case, the new ones are in and properly tensioned...... Best wishes and always welcome new information so as to keep learning.......

 

[Saukum]

Most timing belts that I have dealt with had nylon cords running lengthwise and really don't stretch very much at all.

 

[normlf]

I didn't say that the belts had stretched a lot, what I said is that they weren't as tight as they should have been.....and between a small bit of wear and a small amount of stretch.....it would explain the tension that I found on the old belts..... most belts have cording and it is often nylon and they don't stretch much, but a little bit is common........it is often very evident with matched belts on multiple groved sheaves...... they can all have uniform tension and over time they wear and stretch a bit...and won't be uniform. Again, not a lot, but it doesn't take very much to change the tension on a belt or belts.

 

[joedrum]

after a motor is timed ...the crank needs to turned to the nuetral possistion ...meaning no valve spring pressure at all on belta this is the conly way to right tension ...once thats done on both sides ...its time to adjust valves

 

[dan filipi]

after a motor is timed ...the crank needs to turned to the nuetral possistion ...meaning no valve spring pressure at all on belta this is the conly way to right tension ...once thats done on both sides ...its time to adjust valves

Also, it makes sense that since the springs are what determines the tension that they too should be replaced when replacing belts if the age of the springs are unknown.
The very first time I replaced belts on mine I bought new springs.
There was a difference for sure.

 

[normlf]

springs fatigue.....no doubt about that at all. How much and how fast is a question that I can't answer, but probably deals with how many expand / contract cycles and heat and cold plus the alloy involved and whether there is any danger of overextension or compression....that sort of thing. Now consider that the springs in question are not flexed at all once they have done their job of pulling the idlers into proper tension. So no repeated cycling; no overextension possible; no excessive heat likely; etc. The most prudent would be to replace the springs each time belts are replaced......it may not help, but it can't hurt either. Another issue would be any corrosion...which should be nil considering the covered location. I do know from aviation issues that if in doubt...do it. And springs and such are always replaced in critical locations; it is just the prudent thing to do.....or as with automotive valve springs....non-destructive tests and limits for approval for continued service....all based on engineering and practical application over time.

Conclusion.....if you want something to be like new and guaranteed to be within service limits...then replace and test the part prior to installation as new parts are not always good....unless there is 100% testing on parts, which is highly unlikely on a conusmer item such as a motorcycle....or the costs would be too high for the final product. Also, slavish adherence to the recommended procedures is mandatory..short cuts should be avoided..... Some work fine, but sometimes the expedient way can lead to trouble.

Nothing is quite as simple as it seems on the surface...and some things even if done wrong may work most of the time...but can lead to disaster. Like leaving the adjusting screws on an oxygen regulator turned in all the time....and turning torches on and off by opening and closeing the cylinder valve only. Do that enough times and on one out of thousands of times....boom......but it is rare.....but possible. Playing the odds is gambling......in some cases that produces nothing; in others it ruins something; in others death could result. How many bolts properly torqured ever come loose.....so then why screw around with saftey wiring propeller mounting bolts....the answer is obvious!

 

[joedrum]

1/4" deflextion both ways or a little less is what i do

 

[mcgovern61]

But..........but............you only have spring tension when the belts are not in a neutral position. Once the belts are properly tensioned, you lock down the adjuster permanently until the next time you do the belts. The springs are not constantly expanding and contracting (other than from the heat of the engine) as the belts are turning (if you will)?

 

[AApple]

Thread moved from New Member Welcome to GL1100 forum, since it has turned into a tech discussion. k:

 

[dan filipi]

But..........but............you only have spring tension when the belts are not in a neutral position. Once the belts are properly tensioned, you lock down the adjuster permanently until the next time you do the belts. The springs are not constantly expanding and contracting (other than from the heat of the engine) as the belts are turning (if you will)?

Agreed.
I mentioned the springs because I saw and felt a definite difference compared to new springs and they are very inexpensive making replacement cheap insurance.

 

[normlf]

I fully understand that the springs are there for only one purpose and that is to put a designed amount of pressure on the idlers when new belts are installed and the are dead weight until the next set of belts are installed......and your point? The are supposed to eliminate subjective judgements...... Also, someone mentioned moving the crank to a point where there is no valve spring pressure on either belt....that makes sense, but is not spelled out in Honda's procedure for changing belts, but would be significant if you don't make sure that the belts are both tight on the side opposite the path over the idlers.....and that can be done easily enough. I did exactly that and then double checked the belt tensions after manually rotating the engine through several 720 degree rotations of the crankshaft.....the amount necessary to have the full four strokes completed on both cams...... the the tension / deflection of both belts should be identical...and if not, then something is not right....

 

[normlf]

Fully agreed....to return any mechanism to "new" condition, it is always a plus if you can replace parts like springs with new....as there are difference from subtle to major....but things do change over time and through wear or fatique of corrosion or ??????

Cheap insurance.....right on. On the other hand in a professional enironment or in critcal applications wear parts have design limits and if you know the limits and can test those limits accurately....replacement can be determined to be unnecessary. However, the cost of removal, testing and replacing may cost more in time / labor than the worth of the new part.......like lock nuts in some places...or springs or ?????

You seldom make things worse by putting in new parts.......and better to spend an extra few bucks to renew a part especially one that is critical or hard to get at or impossible to get at once a mechanism is in service.

Those kinds of decisions go on every day in aviation.......at all levels.....but probably more in private, sport aviation where people have limited budgets and a desire to manage costs and many of the decisions are between the A & P and the owner...... and are judgment calls not prescribed by rules and regs.....and even many of those are judgmental......

 

[joedrum]

theres a lot of things ive found that homda completely drop the ball on ....the dam spring is useless ...give a desired deflextion and move on ...give me a cam pulley with only one right mark ....but yes the nuetral adjusting is the only way ...only place where both sides can be done equal in the start

 

[Omega Man]

Welcome to the forums! Those electrical problems can be "vexing" I've done a couple work-arounds I'm not very proud of. oh2:

~O~