Author Topic: R loom question  (Read 296 times)

epa police

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R loom question
« on: May 06, 2018, 10:57:55 PM »
Asking this for someone else. He has an R that he is putting an SP motor into. He has the SP carbs and Sugo CDI so the question is will the R loom work with the SP set up. I know he will have to make the bit of loom to take the PJ solenoids for the carbs but seeing as the R didn't have the PJ carbs will it even all play together. 

ybk

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Re: R loom question
« Reply #1 on: May 07, 2018, 12:30:43 AM »
My understanding is that the R loom will be fine. The VAJ wires can be recycled as the PJ wires with suitable connectors. Never tried or did it in practice though..

epa police

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Re: R loom question
« Reply #2 on: May 07, 2018, 10:06:03 PM »
Cheers YBK I thought it might be similar.

Warwick

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Re: R loom question
« Reply #3 on: May 09, 2018, 01:20:55 AM »
Yes, the R loom will work fine. Solenoid shut off control will just need the existing VAJ switch wiring and live feed as you've already mentioned. 
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epa police

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Re: R loom question
« Reply #4 on: May 09, 2018, 02:18:10 AM »
Cheers Warwick

Scotty4321

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Re: R loom question
« Reply #5 on: May 09, 2018, 08:13:27 PM »
Not sure how others have got on but I gave up on the EPJs in the end. I found that by the time the fuel had got up from the bowl to the jet it was time to change gear. So basically no fuel was actually getting via them into the engine.
I had clear pipe that had some copper tube inside it to reduce the volume to try and speed up the flow. Maybe something is wrong with mine but they were both the same. Could well be related to not having the sugo parts for the SP carbs, possibly they produce more of a vacuum on the pipework. I'm not sure though if the sugo carb parts are required to get success with the EPJs.
It was a while ago but my understanding was that they should flow fuel over a certain range but switch back off at the very top of the rev range to give more overrun.
I was using a Zeel and so could program the switching of the circuit at whatever revs, with a sugo box there is no such option and therefore the timing of the fuel may be even more critical. Cheers Scotty

vinny

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Re: R loom question
« Reply #6 on: May 10, 2018, 10:02:32 PM »
When I first fitted my sp carbs the Power jets were very intermittent .
The first thing i did was made up little adaptors with bulbs are plugged into the loom instead of the Power jets.
Then I was able to see by running the bike what was actually happening.
It was crazy one wasn't doing anything at all and the other was only lighting for a fraction of a second .(this was with a sugo cdi which turned out to be faulty )
Next i tested the solonid and made sure both were actually working.
The wires into one were faulty (pretty commonplace) .
I soldered it up and got it botched .
Then I fitted a zeel ( i was planning on fitting this regardless) and was able to set the cutoff revs for the solonid.
I set this a bit lower than standard because as Scotty says it's was only closing and it was time to change gear  ( gota mind that crank )😉.
Took a bit of time to sort it all out but works perfect now .
Did it make any difference to lap times probably not 😏.

ybk

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Re: R loom question
« Reply #7 on: May 11, 2018, 12:21:54 AM »
Not sure how others have got on but I gave up on the EPJs in the end. I found that by the time the fuel had got up from the bowl to the jet it was time to change gear. So basically no fuel was actually getting via them into the engine.

Interesting point, you can probably measure the time it takes to suck fuel from the bowl and out the jet and time everything better with the zeel as vinny did. I thought the PJ's would prime the pipe on startup first, kind of like holding water in a straw, then the fuel would be ready when needed.

Scotty4321

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Re: R loom question
« Reply #8 on: May 11, 2018, 07:27:41 PM »
When I tried them I was at the dyno and so could see the A/F ratio for any changes. With clear pipe you can at least see the fuel travelling up when the bike is spinning up. It's pretty slow to act I found.
Without a dyno it is going to be difficult to see either. Care is required and the only sure way is as above or to at least have something close to the full sugo setup.
I ended up with much larger mains than I thought I would and just plumbed in some small tees with an air jet in the pipe that used to go the VAJ blocks. I tried some RGV variable timing air sovs (4LO4ever's) but ran out of time. This is the way forward if you have time and a zeel as you can tweek the duty cycle in the program at any revs setting. That way you can get the A/F ratio wherever you want it at different revs. Surely better than EPJs, however they were successful for Yamaha back in the day.