that has to be a sweet ride when you are all done. but of luck with it.and you might want to p.m. hyperfomace and talk to randy i'm sure he's done a few.

 

I'd like to know that too.

 

"The 131 has some improvemenents. Huge ports that really flow. I think they have better valve springs. "

"The cam is now a .635 lift from the Jims factory. On the 120, it was a .650 lift.
By the way, these motors run pretty hot (like having a nuclear reactor between your legs) when you break them in during hot Texas summers. The heat thins the oil. The oil pressure drops....yada yada. I had the oil pressure relief spring replaced, changed to Amsoil 60W Racing Oil, during the summer break-in. I also put an oil temp gauge in and added a mechanical oil pressure guage."

"These motors vibrate a little more cause you wanna drag race them a little more. I had exhaust flange bolts, oil pan bolts, air cleaner bolts and several other bolts vibrate loose and off. Treat the bike like your doing air craft maintainence. I also use the K&N oil filter with a lock wire on it after the Oil filter vibrated loose."

"All in all, the bike is scary powerful and I would not trade it. Good luck, Steve"



Every Jim's 120 and 131 had the SE -264 camshafts. Both engine recieved the SE cam plate and high flow oil pump over the early 120's. The 120's issues were with the tappets. They installed stock tappets on 120's until the Powerglide II's were introduced. Mine still has the stock tappets. The engines are identicle except the 131 has a 4.313" bore and 4.500" stroke. It runs 10.5:1 compression. The 120 uses a 4.125" bore and 4.500" stroke and has 10.0:1 compression. Heads are and always have been identicle. Increased compression on the 131" is from increased bore. I had the stock cam plate with old style tensioners. I installed T-man 650 gear drive cams and Fueling cam support plate. All Jim's engines have the new roller style chain and cam set up. I have never had anything come loose or fall off of mine.
Another thing to let everyone know. These are Harley's engines. MOCO designed and spec'd the motor. Jim's assembles. Has Jim's wheels and some other parts, but Hd does the cylinder's, heads and everything else. That is why Jim's doesn't do too many discount deals on these motors. All are invoiced by the MOCO.

 

What are the thoughts on going to final Chain Drive on a motor like the 131. Do you think the belt drive will hold up? And how about any chassis modifications. Will the stock chassis/frame need to be re-enforced?

 

What are the thoughts on going to final Chain Drive on a motor like the 131. Do you think the belt drive will hold up? And how about any chassis modifications. Will the stock chassis/frame need to be re-enforced?

 

I have around 20,000 miles on a 2006 JIMS 120 with heavy mods... and NO problems. YES she shakes & YES she gets HOT. That should be expected with a big engine guys.

I swapped out the tappets as soon as they became available. JIMS warrantied them but I would have put the PGII tappets in regardless. I plan to switch them out every 10,000 miles or 2 years. May go with a set of Fueling Lifters from Zipper's Performance instead.

Speaking of Zipper's - if you want an INCREDIBLE turn key system for either of the JIMS engines go with the Zipper's Thundermax with Autotune. It is an AWESOME system that WORKS & is VERY RELIABLE.

FYI - throw the OEM clutch away & go with an Energy One. The stock clutch won't last long enough to run around the block if you're really ON it... and you'll ALWAYS want to be on it!! Also, the belt final drive will hold up for awhile but chain is the way to go if you want to put the power to the pavement. It is the MOST efficient drive available and since either JIMS engine will cost you $10,000 or more (with everything) doesn't it make the most sense to put down as much of that bling as possible?

 

I have a customer that has a few thousand miles on his 131 Jims and has no problems. Of course with a measly 131 CI you need head work and and other work so no one would consider the 2006 Dyna a slouch according to my customer. We are putting on duel disk brakes as you need to haul it down from a greater rate of speed. I have heard no complaints from him and all of the information is from the customer only.

 

No doubt there will be a little vibration simply because you are swinging bigger pistons on longer arms,it's a given! The same with heat,the more cubes the more friction and fuel the motor can digest!The clutch is a must do and there are a lot of choices,mine have Barnett Scorpions,simply because of reputation and years in the business.Rear drive?both my bikes have the 1 1/2" Kevlar belts with no thoughts of failure,because of the way I apply power.Several friends also riding big inch machines up to 155" running belts.You gotta do what makes you comfortable.You won't regret going the big inch except for accelerated rear tire wear.Jim's certainly builds quality products!Good Luck

 

I put a 131 on a 2002 Heritage. I have 2,300 miles on it now and put it on the dyno this week. The torque numbers were real good, 141 lbs. But the hp numbers were a little disapointing, 117 hp. I have a 48mm Mikuni carb on it and the only way the tech could get the fuel air mix right was to install a smaller jet than came with the carb. He had to go to a 170. The smallest that came with the carb is a 190. He claims the carb is to small to feed enough air. I'm running a S&S intake, R&B header pipe. He claims I need to convert to fuel injection. Don't know if I'm ready to cough up another 2 grand to do that. Other than that I'm tickled to death with the motor. The fuel usage is the biggest surprise to me. With the wife and I running 70 mph it'll get 41 mpg. My old motor which was a heavily built 95 got way less, about 30. I forgot to mention this motor makes 125 lbs of torque a 3,000 rpm, that's killer.

 

This must be the older motor w/ all the issues?

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