Timing Belt Change

Getting my 1981 GL1100 Interstate safetied today so in theory I will be able to drive it next week. Over the weekend I'd like to change the timing belts. I ordered 2 Gates belts from eBay and they arrived yesterday. I have reviewed the timing belt change proceedure and I'm good with how to do it but I have a couple of questions. First I see some people talk about doing the job without removing the rad. It does look like it's possible but I'm wondering if it's not just as easy to pull the rad and have full access? With the rad in place I'm wondering if you can see the center shaft well enough to get it lined up properly? Is it a pain to take the rad out and does the rad and fan come out in one piece?

Second - I see that the belt tension is established by the spring attached to the pullies. It looks like after the tension is set by the spring the pully is bolted in place. I'm wondering how accurate this will be considering the springs are probably 30 years old. Does everyone go with the spring tension or do you add a bit? I also have a force tool which I could use to press down on the belt to a known force. The tool's range is from 0 to 10 Kg's. I was going to measure my old belts pully tension before I removed them. Any comments or tips would be appreciated. Thanks.

When I changed my belts I took the radiator out with the fan attached. While I had it out I inspected it and foune it had been leaking and probably had stop leak added to the system to control the leak. I was unable to find anyone in my area to repair the radiator (EPA has hammered most of them out of business) so I found a good used one on Ebay and replaced it. I find it a great time to check the entire system so I also put new hoses, thermostat, and water pump which had loose bearings. I have a deep aversion to the Harley syndrome of being found on the side of the road with problems so in my mind maintenance is king.

When I changed the belts I found that the springs did not in face tension the belts enough and one of the old ones was quite loose. I applied additional pressure with my thumb to get the desired tension. Careful with this as over tightening could cause overheating belts and failure.

Hope this helps

The belts should have about a 1/2" deflection (is that the right word?)

It's not really necessary to see the center (crank) shaft because you should be using the flywheel timing mark on T1 to line up the crank.
If you loosen up all the radiator bolts and take the front pump flange bolts out the radiator will move forward quite a bit. Bungy the radiator bottom forward.

Personally...I always pull the radiator because I find it easy enough to do and I like full visual access to the belts and pulleys. Plus I find it much easier when you put the belt covers back on. It also gives me a good chance to check my water pump shaft while the radiator is off. (I do not remove the lower hose, I unbolt the pump cover)

The tensioners are only used to set the belt tension. Once set, you tighten down the bolts and the tensioners are fixed. That is also why it is important to get the belt tension correct before you tighten down the tensioners. Over tighten and the tensioners will whine and sing (plus it will cause the tensioner bearings to wipe out real fast!).

Before you button up, don't be afraid to ask questions!!!! Incorrect procedures have caused many a bent valve on these engines....there is no room for mistakes! (Literally...if the belts are not put on correctly, the pistons will hit the valves!)

Before I remove the belts I always check that the timing mark is correct and the pulleys are in exactly the right position (looking at the engine...pulley marks are exactly at 270 degrees and 90 degrees respectively and the up arrow is exactly at the top 000 degrees on the pulleys.) I then mark the crank pulley at the top with white out and the timing marks on the pulleys (left and right). When you pull the belts, the right side cam (left looking at engine from the front) will turn from spring tension on the cam. Having these marks will help line everything back up and prevent you from going "one tooth off" on the belts.

I always start putting the belts back on by putting the right belt (left looking at engine) on the crank pulley first while the crank pulley is in the 000 position. I keep hand tension on the underside of the crank pully on the belt to keep the teeth lined up and pull the underside of the belt belt while turning the cam pulley to the right position with a 12mm socket on the pulley bolt. The belt always slips right into place when I let the tension off the bolt and let the cam spring tension hold the belt. Cam pulley and crank pully marks should still be lined up. Then I slip the tensioner on. Move to the other side which is much easier since there is no cam spring tension.

After both belts are on and the tensioners are under tension but not bolted down yet, I turn the engine by the stator bolt with the plugs out and check for any interference or noise from valves touching turning the engine several times. Observe your belt tensioners during this process to get an idea of how they work. Line up the timing marks again and check to see that the pulleys and crank end up at exactly the same place. Right side pulley should be tensioning the belt under tensioner spring pressure. Tighten it down. Turn the engine 180. The other tensioner should have the belt under pressure...tighten it down. Crank by hand at least 4 more times through 360 degrees and check your belt tensions. There should be at least 1/4" play and up to 1/2".

I didn't remove or loosen the radiator on my 83 Interstate and won't when I do it next time. The only difficulty I found is that the inner left (from the front of the bike) cover bolt was hard to get a wrench on. I heated the shaft at the box end of a cheap wrench and flattened it out with a hammer to take the angle out and it worked fine.

Saber sells a tool for this but I personally wouldn't bother.
Try it. If it is a problem you can always loosen the rad.

Jorg

I'd add that by loosening all the valve tappets all the way loose you won't get the "spring back" effect on the right cam.
Having them loose is a very good safeguard in preventing a bent valve since the pistons will be at Top Dead Center so turning either cam will open a valve and risk bumping a valve head. They bend easy.

Since the engine guards are off and all it's a good time anyway to adjust the valves.

once you change the belts and they are timed right with the valse all loosen up and you have check it for clearence by hand with crank bolt or sator bolt ..i like the crank bolt you can turn the crank by hand and get onr side to wher the cam is in a nuetral possistion and put the right tension on the belt here easy by putting a little tension on the cam pully and let the tensioner move up to take up the slack not mush force here and tighten ...this give proper tension and then do the other side the same way .....after that turn by hand again to check for clearence ..and them adjust the valves and turn by hand again ..if you need more help or dont understand will give a complete process how joe ...dont be guessing here at all always ask first before trying the bike we dont want to harm any of our bikes :mrgreen:

Thanks very much for all the helpful replies. I will probably remove the rad just because it will give me the opportunity to change out the fluid and inspect my water pump shaft and impeller. I also think I will back off the valves the way it is described in one of the procedures. It sounds like taking the spring tension off the cams makes getting the belts on without the cams moving a little easier. I was planning to check the valve rocker clearances anyway. One question - do the valve covers come off and go back on OK without replacing a gasket or o-ring? I'd prefer not to have the valve covers leak oil after all this.

yes ...just be careful and extermly clean ...its always worked for me :mrgreen:

im going to change cams in my 83 today now that i leaned how to post pics and i will start a thread with pics joe :mrgreen:

On the cam covers, the bolts have a stop and only thread in so far. Don't try to torque them down to make the cover seal tighter, that will only strip out the threads.

dan filipi":poda9455 said:

On the cam covers, the bolts have a stop and only thread in so far. Don't try to torque them down to make the cover seal tighter, that will only strip out the threads.

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Or break inside the head!!! (Don't ask me how I found that out!! :rant: :rant: :rant: )

Just like to report that I got the belts changed successfully yesterday. I ended up removing the rad which required removing the seat and the faux gas tank. After the lower fairing pieces and the rad was out of the way there was lots of access. I loosened off the valves as suggested and it did make the cams less prone to move. I still found that the right cam (left when facing) had a bit of valve spring tension even after the adjuster was moved all the way out. I believe it was cyl #3's intake valve. Just at the point where cam arrow is lining up with the mark on the housing the valve's rocker would start to press down on the valve even after the adjuster was moved all the way out. This meant the cam alway wanted to roll back a few degrees from the mark. I also found that the crank pully moved very easily and quickly discovered that after I thought I have the belt on correctly the crank had shifted slightly off the T1 mark. Some frustration at this point. :sensored: I ended up putting the belt on the left side (right when facing) first. This was easy as there was no valve spring tension on this cam. After I had that belt on and T1 was still lined up properly I took two large plastic spring loaded clamps that I have and clamped the cam in place. This effectively locked the crank in place so that it would not move so easily off the T1 mark. I then went back to the other belt and was able to get it on properly after 3 or 4 tries. Not having the crank move as easily seemed to be the the solution for me on this side. After both belts were on and the the tensioners locked down I slowly rotated the engine and checked several times to make sure the cams were still lining up with T1 and they were. I then adjusted all the valves in the order described in the manual and slowly rotated the engine again checking for interference between valve and piston. There was none. At this point I cleaned and polished the valve and the timing covers reinstalled them. I put the rad back in, reconnect the hoses and realized I hadn't remembered to plug in the fan motor. Some frustration at this point when I discovered that I couldn't really get my hand in there to make the connection. :head bang: :sensored: Had to remove the rad and get my wife to plug in the fan as I held the rad just below it's mount point. Had a beer at this point. I put new anti-freeze in the rad at this point and with the fairing, seat and gas tank off I decided to fire it up. No point in putting everything back on unless it starts. This was my most nervous moment. I had visions of the belts coming off and the motor self destructing. I turned on the key but turned off the kill switch and rolled her over a few times. All sounded fine. I then flipped the kill switch to the run position and pressed the starter button. It started right up as it always does with this bike. I let her idle for a few seconds and gave her some revs. To me it sounds smoother and perhaps idles better. I let her idle while watching the level in the rad. As it warmed up I topped up the rad and put the cap on. I then filled the over flow to the high mark. I continued to run it till the fan came on. This took about 15 minutes. A final inspection of the rad and hoses showed no leaks. At this point I was very pleased so I put my tools away and called it a day. Total time was 5 hours and one beer. I'll put the fairing and the tank on today and go for a test drive. Again thanks for all the help with this. :thanks:

great sounds like did good job and your right getting the crank no to move is a big help on getting the right side on right ....and also getting the tension right on the tensioners is a big deal too ..... :heat: :mrgreen:

Great job! Love success stories! Now...go ride and have fun! :clapping: :music:

That's great Lcol!
I love it when the plan comes together as it's suppose to.

Many a time I've had the crank move :sensored:

dan filipi":3dd0t18v said:

Many a time I've had the crank move :sensored:

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When I changed mine and before removing the old belts, I made sure that the timing was correct. I then marked the cam pulleys and both belts at the timing marks. I also marked the crank pulley and belts at 90 and 180 degrees. I then counted the teeth from mark to mark and transferred this to my new belts. The gain is, when the crank and cams start moving, there is no need to fight everything back to the timing marks, just use the marks on the belts and pulleys.
:smilie_happy: :smilie_happy: He forgot to plug his fan in before remounting his radiator. :smilie_happy: :smilie_happy:
Yeah..... I did too. :head bang: :sensored: :rant: :swoon: :smilie_happy:

OK so I am planning this trip to Seattle Wash. then Sacramento Calif... Why do you ask? Because the only way to get from Seattle to Sacramento is to go to Seattle...It dosen't matter that I live outside of Sacramento :smilie_happy: ..I am to meet friende who are on a trip from Chicago via the northern boarder of the US through Seattle and down the coast to Sacramento.
Now to prepare for the trip I installed new timming belts..Pease of cake (thanks Bev).. drained and cleaned the cooling sys...Changed the oil...Inatalled new exhaust gaskets. Reset the tappets. Installed new rear break pads.. Need to change rear rotor...Have new parts for carb rack and new fork seals (time permitting) I got side tracked on cosmetic things....I sand blasted my valve covers and did some polishing My $25.00 garage sale find (sand blaster) the onr on the left is how they looked before..The one on the right is after sand blasting. now the one on the right is after some polishing, only to the raised protion
If I get to the front forks I will do the same to them.
Now i have to go take my shower and get all the sand out of my hair, eyes, nose, shirt, pants,shoes and the nether reagens :lazy: :lazy: arty: :yahoo:

Bob....share some details on the polishing part! (Looks great!)

$25 sandblaster eh? No bargains like that around here!

They look great and the polish looks really even.
How did you do it?