Topic: 836 kit, Web Cam, Kerker 4/1, and K&N's - Ride Expectations?

[RRRToolSolutions]

2 weeks ago, I picked up my 1st Honda 750. This 74 model was purchased for $112 on EBay, then I drove to pick it up so cost to get started was minimal.

Today the bike is stripped and all black parts are at the powdercoater. The chrome is at the plater, the tank has been color-matched, a quart of Dupont Chromabase is in the garage just waiting on the NOS side covers to arrive so they can be painted together, and hundreds of new parts including NOS seat, rims, spokes, ect are ordered for the assembly.

The plan is to assemble a good looking CB750 with mostly stock parts, but have a 70-'s style hotrod. I've never ridden a stock CB750 and I don't remember much about my high-school friend's bike. How does the hotrodded 836 compare to stock? Will it still be torquey and come out of the corners strong? Will it have any bad habits in cruising range and leisure riding? I'm not building a race bike, just a fun rider that sounds, looks, and has a kick. I'd planned to get the Web cam they recommend for the 836 kit and the springs to co with it?

I'd really appreciate some 836 owner's imput. Would you do it again? Would you recommend it for casual riding? I've bought the Wiseco kit, but haven't sent the cylinders out for bore/hone yet. Opinions really needed.

Thanks,
Gordon

[Sam Green Racing]

Search 836 power.

Sam.

[HondaMan]

Be ABSOLUTELY SURE that the machine shop gets the bore clearance and crosshatch angle (honing) correct, or it will burn oil from day one, and never quit. This is one sensitivity of the 836 kits. DON'T let them talk you into "we'll give it a little extra clearance." Stick to the spec: check the 836 power notes in this forum. Personally, I'd go for .0010" clearance ONLY, but that's my preference.

If you have the rings, take them with you to the machine shop. Cast iron rings require different crosshatch angles from chrome rings. If the shop tells you "this doesn't matter", take it to another shop. It DOES matter.

With the 836 heat, run 20w50 oil for best results, or run synthetic.

That's my nickel's worth!

[Sam Green Racing]

Gordon, don't forget, to get the best from this kit, have the head ported.

Sam.

P.S. Haven't we allready been down this road.

[sandcastcb750]

I had a shop put the 836cc kit in my 1971 CB750. Also, it has a new Kerker. I have had mixed reactions from the engine job.

First, it is much faster. But, most of the power kicks in at 5-8 thousand RPMs. Maybe a little faster at the lower RPMs. More fun to ride. I miss the raw power of my CBX that this 836cc will never have; I thought the 836 with cam and Kerker could approximate it. Modern bikes will always be faster. A 1991-2003 Nighthawk 750 runs quicker too. But ofcourse, this is a nostalgia thing with the old CB750 SOHC that new bikes will not give you.

The bad. It burns oil; always. After 500 miles it developed an oil leak at the left side of the head. The guy said he fixed it after I brought it back to him but I guess he was too lazy to remove the engine and do it proper. Still leaks and my left pant left wear oil to prove the ride. It smokes during idle.

It pings on all types of gas. No additive helps. I wonder if too small jets cause lean burning and the ping.

It is hard to kick and if the battery is weak, will not start.

A stock clutch slips with 836cc. Had to get a Barnett.

I will never be totally happy until the oil leak stops. I hate to remove the engine ( or pay someone else) but I need to do it.

Am I the only guy with this problem?

[MRieck]

 Some questions. Did you recondition the head (new guides, valve job and seals? I believe you still have the exhaust guides with no seals in there). Is it a 10:25 kit? Was the head milled much? Are you using the stock cam. Does it still have points? Is the advance unit frozen on full advance? The leak is probably from the oil return passage as the early engines didn't use dowels and rubber doughnuts to seal. It could also be from one,or more ,of the sealing discs under the cam tower not being replaced with new ones during the rebuild. You have to make sure the head and deck are flat and use some sealer around there and torque the head down properly. The clutch only needs Barnett springs to stop slipping. And yes, modern bikes do make a lot more power and handle better. A new 600 has twice the HP of a 750. Mine is 915 with alot of work and 600's still have 12 to 14 more HP (though I have more torque).

[eurban]

The Weisco 836 10ish:1 CR kit makes for a very nice daily rider.  My ride (78K) has this in conjunction with a Webcam 41a, very mild porting, pod filters (for looks only, I doubt my bike performs better with them!)  and a Dyna III ignition.  I couldn't give up the look of the stock 4 pipes, so thats what I use . . . It  pulls very nicely with a good bit more (than stock) low end power and a bunch more at the top.  Haven't had it Dynoed yet.  The 836 kit  is a fairly significant change in the size and CR vs the stock engine and when combined with mods to the intake and exhaust will almost certainly require tuning to the stock carburetion inorder to get good, reliable results. . . . My setup runs well on high octane gas with no pinging and as of 1.5 K I don't leak any oil.  Suggestions:  use chromoly cylinder  studs (if you install all your gaskets and rubber bits right, with these studs you should hold proper torque and not leak; replace your cam chain with a heavy duty one, use a new tensioner wheel setup; performance valve springs and keepers are a good idea even with a mild performance cam; install an quality oil cooler (more power and higher compression ratio will heat your oil a good bit more than stock so I can't see spending the $ for a hot rodded engine and not adding a cooler); spend the necessary time to get all the bikes systems in tip top working order and then tune your carburetion.

[RRRToolSolutions]

Wow, this is an old thread - I posted this originally back in early June, just 2 weeks after I picked the bike up from the $112 EBay purchase.

I did the 836 Wiseco big-bore, Mega cam, titanium tetainers, dual performance valve springs, brass inserts, Barnette clutch, NOS clutch plates and fibers, Kerker 4/1, Stage II porting, oil cooler, Dyna 2000 and coils, K&N's jetted perfectly, and I really like it.

I screwed-up in 1 area - Big time. I "cheaped-out" on the Carillo rods. This stock geared K4 starts pulling the front tire off the ground at around 7,500~8,000 rpm. I installed the Barnetts and the Dyna 2000 with a rev limiter because the motor ripped through the stock cluth and 10,000 rpm without them. If I could stay in the throttle, it would really snort, but because I cheaped-out - I'm handcuffed to a 8,500 rpm limit "just where she starts making real power". I will add Carillos and chromemoly studs one of these days.

I've got an old H2B 750 and a ZRX that will eat the Honda for breakfast head-to-head, but neither will do it at 2,800 rpm or in 1970's style. I like the low and mid range this combination yields. I'm 240 and can loaf around at 2,500 and still pull out of corners without a hickup. I can also nail it to the limiter and smile wide - it's a fun combination.

I had the leaks also. Here is the 2nd time around at replacing those darn rubber cam tower sealers and new cover gasket.

Regards,
Gordon

[Big Jay]

Do yourself a big favor and get our nine disc clutch kit. It has ywo more friction plates than stock and will hold more power than any other clutch available for the 750.


Jay

[maksuttt]

Do yourself a big favor and get our nine disc clutch kit. It has ywo more friction plates than stock and will hold more power than any other clutch available for the 750.


Jay

I like this kit, but it's not easy to install on F model - i had to use one original face friction disc because of clutch drum difference (used only 7 APE discs)

[mlinder]

Soon as I win the lottery, I'm goin for the carillos and full build up.
Until then, I'll settle for slight improvements

/edit: Anyone seen or used the R&R Cold Extrusion Aluminum Billet rods? Don't know if they have any for a cb750, but they look nice, are low weight (less reciprocating mass), and according to them, quite strong. (Also, according to them, does a better job of 'cushioning' impact shock between cylinder and crank shaft than steel.)

[dusterdude]

Soon as I win the lottery, I'm goin for the carillos and full build up.
Until then, I'll settle for slight improvements

/edit: Anyone seen or used the R&R Cold Extrusion Aluminum Billet rods? Don't know if they have any for a cb750, but they look nice, are low weight (less reciprocating mass), and according to them, quite strong. (Also, according to them, does a better job of 'cushioning' impact shock between cylinder and crank shaft than steel.)

all the above is true,however aluminum rods do not have the life cycle a steel rod does,so therfore every so often(and who knows when that is)you have to replace aluminum rods.

[RRRToolSolutions]

Yea, what Duster said - The aluminum rods are for drag engines and would be regular replacement items. They do save a lot of shock and wear on the crank - but at their own life's sacrifice.

Carillos just rule, they just do.....