Stock Cams to S&S 509 Cams
#1
Stock Cams to S&S 509 Cams
I have a 2000 Heritage (28,500 miles on it) with CV carb, stock cams and Vance Hines exhaust. I'm installing S&S 509 cams, new outer and inner bearings, and changing the OEM chain tensioner shoes to Cyco brand. I'm assuming I'll have to increase the jet size on the carb. Should I go 2 or 3 sizes larger and then go smaller by one size after inspecting the spark plugs? I'm trying to avoid a dyno test. I'm the second owner of the bike and I haven't examined the carb yet so I don't know what jets are in there now. Thanks.
#2
#3
Don't disagree with roadmutt but suggest going up say from 175 to 180 on the main; IAW a "half size" up from the current main while you futzing with the needle; start with one .025" SS washer to raise the needle. Avoid Yost or Dyno Jet kits and stick with OEM parts. Consider drilling the vacuum port to 1/8" and installing the lighter spring. This has helped throttle response on the CVs I have worked on. With the needle up .025" and a half size larger main, use that as a baseline for further tuning; better to start a bit rich than lean. You might talk to a local tuner to "buy" an hour of dyno time to check AFR and partial and full throttle. Take a handul of those washer and a couple of larger mains and you can tune the carb in an hour.
Timing could be an issue as the stock timing may be too far advanced for a cam upgrade; corrected compression and CCP are both going to jump up which could result in timing issues. A programmable ignition like the DTT TC88 would be a good idea if it is in the budget. Just pay attention and watch for running hot and listen for ping.
Timing could be an issue as the stock timing may be too far advanced for a cam upgrade; corrected compression and CCP are both going to jump up which could result in timing issues. A programmable ignition like the DTT TC88 would be a good idea if it is in the budget. Just pay attention and watch for running hot and listen for ping.
Last edited by djl; 05-09-2019 at 01:28 PM.
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roadmutt (05-09-2019)
#4
I got the bike the other weekend and started taking parts off in prep for the cam swap. I spent about 6 hours the first weekend taking off the gas tank, seat, exhaust and saddle bags. Today I spent about 8 hours removing the valve covers, rocker boxes, push rods, lifters and stock cams. The cam tenioner shoes are getting replaced but I was happy to see that they were both intact. The only potential issue I see is the cam retaining plate (part # 35060-00. It has some scoring and loss of material on the outboard side at the front cam. I only had to press out the bearing for the front camshaft (the rear camshaft would of slid out of the support plate if not for the chain).
#6
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