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Author Topic: Engine install and set up questions  (Read 1138 times)

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ThomasJ

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Engine install and set up questions
« on: May 16, 2005, 08:08:29 pm »
I just got my engine back from the shop. I got the cylinders honed, new rings, camchain, camchain tensioner and front guide, head was milled 10 thousandths, clutch plates, valve job, and valve seals.

I have three questions. Will the engine fit in the frame when it is complete? I hope it will because its already all together except for the oil pan, oil pick up, and oil filter.

Next question is about jetting and timing. I have a mac 4 into 1 system and open K&N filters. What pilot and main jets should I use? I know the bike was very lean in stock condition so I dont even want to run it until I get the correct jets.

If I am willing to run premium fuel can I run a few more degrees of timing for more power?

Its a 81 CB650

Thanks

Offline chrometank

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Re: Engine install and set up questions
« Reply #1 on: May 17, 2005, 04:28:22 am »
gday ,yeh the motor goes straight back in without the oil filter atatched.you should put the pan on first.Engine goes in from the right side .when putting it in raise the back and you can ease it in .A two man job.cant answer the other two questions

Offline Geeto67

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Re: Engine install and set up questions
« Reply #2 on: May 17, 2005, 04:36:46 am »
Quote
just got my engine back from the shop. I got the cylinders honed, new rings, camchain, camchain tensioner and front guide, head was milled 10 thousandths, clutch plates, valve job, and valve seals.

I have three questions. Will the engine fit in the frame when it is complete? I hope it will because its already all together except for the oil pan, oil pick up, and oil filter.

Why wouldn't it, it is basically the same as when you took it out. Having the head milled changes very little. externally. Of course we are talking about a stock engine and a stock frame....right?

Quote
Next question is about jetting and timing. I have a mac 4 into 1 system and open K&N filters. What pilot and main jets should I use? I know the bike was very lean in stock condition so I dont even want to run it until I get the correct jets.

The rule of thumb when running K&Ns is to run one size up from what ever you had before putting the k&ns on. IF you are saying the bike is lean to start with then you should buy a bunch of different sizes starting from one size up from stock and increasing. Basically you keep changing jet sizes until the bike runs rich and then go back to the size before. I don't know what jet size is stock or what size you have now so I can't give you a number

Quote
If I am willing to run premium fuel can I run a few more degrees of timing for more power?

Timing is a funny thing, some bikes run better with more advance, some run better with more retard it all depends on how it was built from the factory and how it has been upgraded or rebuilt since. The best way to find out if timing will help your cause is on a bike dyno, but if you wanna try seat of the pants be my guest. Unless you are running a different cam than stock my advice would be to leave the timing alone since hondas always seem to run best when they are timed stock. Your head job has bumped up your compression slightly so I would think you would want to run premium fuel anyway, or at least until your engine is broken in (until the piston rings have seated - don't beat the bike or it won't seat properly and you will get blow by). Since timing issues can masquarade as fuel problems, you will want to get the bike completely sorted out and running right before futzing with the timing.  

I know this doesn't have the numbers you were probably looking for but hey it's a start. Hope it helps.
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Offline cb650

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Re: Engine install and set up questions
« Reply #3 on: May 17, 2005, 02:36:19 pm »
Milling more than likely didnt do anything.  I milled one of my heads .025 and didnt gain anything measurable at the track. 
As far as timing with the cdi these bikes have just set it stock as it wont do much but start harder.
Jets you just have to play with.



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