I have a 79' FX with four speed tranny and a chain final drive. I just bought a Primo 1 3/4" primary belt drive and sprockets and a belt to convert the final drive. I was just wondering if anyone else has done this and if there are any problems I should expect to run into. Everything I bought says "bolts right in" on in but I know from past expierences that nothing ever just bolts right in. Thanks.

 

I believe the rear belt, if you are using a harley belt and sprockets, will require a belt drive inner primary. I only worked on one in my life. The fella who owned it broke a primary chain and it destroyed the inner primary. To go back to the rear belt, he had to buy a belt drive inner primary. (clearances)
As far as Primo, if they say bolt in, it probably does.
One thing to consider. Harley only made a twin belt a couple of years. There is no "Give" in the system, between the primary belt and the rear belt, whereas the primary chain has a compensator to absorb torque and take some of the strain off of the rear belt. When you hammer it, you are one more throttle twist closer to a broken rear belt. Keep a spare rear belt at home. If you are nice to it, it'll last quite a while.

 

we`ve done it a couple times years ago,dont know how your going to not get a belt drive inner primary,unless its a skinny little belt,or alot of machining & fab work
kirby
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I'm thinking a Buel Blast rear belt?

 

al,ever get your oil pump on the dragster figured out?
kirby
facebook: kirby apathy

 

I am going to convert my 1980 FLH to belt primary someday soon. I'm mostly interested in reducing vibration and not having a leaky primary all the time. I have heard that the primary needs to be ventilated or the heat build-up will shorten belt life. How is the belt tensioned in a closed primary? I see some kits that do not have an idler pulley or anything. I'm not 100% up to speed on all this.

 

My advice is STAY AWAY FROM PRIMARY BELTS Unless you wanna walk,or wrench on the side of the road.
I tried it and had to learn the hard way.

 

What are the downsides? Are the belts constantly breaking? I have no problem changing them on regular intervals if it cuts back on oil leaks and vibration.

 

The factory belt drive inner primary had the area around the alternator relieved and the front mounting holes were oval shaped. To adjust the belt tension you loosened the inner cover and transmission and put a screw driver through a hole in the case and levered the cover back. You also have to mill the lower cover screw casting away so the don't grind on the belt. They also used shorter cover screws on the bottom. Harley stopped making belt inner primaries after a couple of years because of the high failure rate. Stick to a chain, a lubed primary chain will last 100,000 miles.

 

Thanks for the input everyone, I appreciate it...