If you are going to do a cam only upgrade, I'm with Kuma. However, IMHO, a cam only upgrade in a TC88 just isn't worth the time and effort. If you want a quicker bike, just convert your 25/36 primary to 24/37 and you will be amazed at the difference; will cost about the same as a cam change but much more satisfying results.

If $$ are constraining, put off the cam upgrade until you have the $$ to have cylinders bored/honed to fit new SE cast flat tops; another $300, thin install the SE204 straight up with a .030" head gasket and you will have something.

 

sounds good,Thanks!!!

 

DJ is right about the gear change. Earlier TC's had this combo from the factory (i know 99 RKs did) and the difference at a 55 mph punch is one gear! I have to go to 4th to keep up. I pass him at about 80 85 but its embarrassing gettin beat by a stock bike. I have 203's, SERT, high flow ac and slip ons. His is bone stock! In a standin start drag race i win but that might be attributed to rider skill. Do both mods and you'll be REALLY happy!

 

Back in 1999, 2000, and 2001 HD introduced the Twin Cam engine on touring bikes with either a carb set up or an EFI option. HD introduced those EFI bikes with the MM EFI throttle body. The carb Touring Bikes were given 3.15 gearing (25/36 primary)and the MM EFI Touring Bikes were given 3.37 gearing (24/37 primary)

In 2002 HD introduced the Delphi EFI throttle body and HD went back to the 3.15 gearing for EFI bikes, while the carb bikes continued to run 3.15 gearing as well. All models from 2002 up until the advent of the six speed has had 25/36 primary gearing.

Coolerman is right, do both and be prepared to buy a new rear tire every season!

 

Thanks dj i didn't know the specifics but i knew my *** was gettin handed to me! I'm considering doing this to my 06 ultra. Am i gonna regret it when i take a long road trip? We usually run 80 85 on interstate. Also is this something a moderate wrencher should be able to do?

 

With your current primary gearing of 25/36 your engine rpm at 80mph will be about 3300, plus or minus; tire size will affect actual. With 24/37 at the same speed, engine rpm will be about 3550, plus or minus. So, you are looking at 250rpm more at your typical cruising speed. So, 85mph with 25/36 primary will be the same as running 80mph with 24/37; not a big difference but it's a personal thing; just like six speed trannys. Unless I toured a lot, I wouldn't invest in upgrading my five speed to a six speed; I like the five speed just fine. The TC engine likes to rev and will run all day long at 90mph; 80mph is my personal "sweet spot"; engine just lopes along effortlessly. If you like cruising 80-85mph, I doubt that the additinal 250rpms at 85 will bother you. Next time you are out on ths interstate, run along at 90 and simulate running at 85 with 24/37 primary and see how it feels.

Fuel economy will suffer a tad, again a personal thing. Some worry about fuel consumption but I don't. As long as the bike is running the way I want her to, I don't mind that she only gets 40mpg; my brother consistently gets 46mpg but he can't keep up with me so who cares.

Yes, you can do it, it's a simple R/R operation with one exception; primary chain adjustment. The stock adjustor won't compensate for the additional slack in the chain. Baker makes a Fat Shoe replacement for the stock shoe; thicker and will take up the slack so you can properly adjust the chain. I don't see the Fat Shoe on the Baker web site any more but understand that Hillside Cycles, a forum sponsor, sells them.

Part numbers for the engine sprocket and clutch basket:
40269-85A is the engine sprocket
37846-99A is the clutch basket.

Understand what you will be purchasing a 24 Tooth Compensating Sprocket HD# 40269-85A which will run $172.80 and a 37 Tooth Clutch Shell Basket HD# 37846-99A which retails @ $310.70.00 (which includes the HD# 37906-90 KOYO 5207 CD3 FG Double Row Angular Contact Bearing and HD# 37905-00 which is the "Large" Retaining Ring that secures the HD #37904-90 KOYO 5207 CD3 FG Bearing into the Clutch Shell Basket). Prices are from Zanotti Motor Company, a discount H-D dealer; you will may 20% more from your local dealer. Of course, you also need to add for shipping.

In 2001 HD changed tensioners to the new style on all models. If you use the old style tensioner and mount it upside down and flip the shoe back over right side up it gives plenty of adjustment; part numbers for the early chain tensioner pieces:

tensioner body 39990-65
shoe 39976-65b
mounting kit 39992-65c
outer plate 39993-65
lock plate 39996-65
(2) shoe bolts 2614

I have heard that some guys have used the HB1125 hydraulic tensioner and shimmed up the shoe but I have never tried it nor would I; don't care for hydraulic primary chain tensioners as they have been known to adjust on their own.

No worreis on the speedo, primary changes do not affect the speedo readings.

If you don't have the service manual, get one; best tool in the box. If you have all the parts and don't run into chain adjustment problems, you can do this job in a couple of hours.

Sorry for the long post but, IMHO, this is an over looked preformance upgrade that anyone can do and, believe me, you will notice the difference; so will your back tire! Additionally, it is one that can be easily reversed if you should decide that you are taking a cross country trip and want to return to the 25/36 gearing for that trip, you can revert to the stock primary gearing easily.

 

DJ you are a plethora of knowledge. I appreciate the long post, very detailed. Now if you would just ride down and do it for me i'd be set. I have the service manual which i refer to often. I'm definately gonna do this on my 06 ultra and if i like the results i'll do it to my 105hp o5 eg. That should really wake it up!

 

Coolerman,
Baker does still carry the Fatshoe. Their PN is DD6-178 $39.00. They are proud of it but it does provide a simple bolt on solution to the problem.

 

Thank u so much Djl,I wish all posts were as detailed as this!!! What do u recommend for the manual...hd,clymer,haynes,chilton etc..... thank again for all the info,that makes more sense!!!

 

The H-D manual is the only one I would buy; a bit more but worth every penny. The service manuals are one of thoe things that the MoCo did right; very informative and detailed. Anyone that plans to maintain their own ride and make repairs should not turn a bolt without the service manual.