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'78 Suzuki TS250C project


DirtyDT
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Not an new oil tank but the recent side panel fitted. The headlight is the one I fitted before Squires last year. It is a pattern CD400 complete unit and fits perfectly.

There are a few blown bulbs and I have put this down to not having a regulator. The UK ones didn't have one but the US and Canada ones did. A new 6v DT regulator arrived this morning so I can mount it to the original fitting and connect it to the loom where there is an existing connector. The new (wrong) battery is fitted and I am getting about 1.7v running charge with the lights off and 6.7v with the lights on. Does this seem right? There is about 9v going to the headlight side bulb which I hope the regulator will cure and might explain the blown side light and tail bulbs.

Engine wise, I still have the problem with the revs running away when the bike heats up. I haven't tried the WD40 trick to see if it is the mag side seal yet but when I do I might as well pop out the seal and replace it. I don't have any other air leaks and the carb is new (thanks Paul) but is there anything else I need to look at?

The original engine is ready stripped but I don't want to start on it as I want to give it a decent lick of case paint and there is too much damp in the air at the moment.

I also need to repaint the exhaust as it has lost a lot of paint where I probably didn't cure the paint quickly enough.

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Hi Paul. I am talking about one of these. 6v but I didn't think they were AC or DC specific!

%21B79cjrQ%21Wk~$%28KGrHqZ,%21lEEy+jCzRQ

Do you think this is a bad idea? It is a 6v one and as far as I was aware it just kept the volts to 6ish and earthed out the rest. Happy for other suggestions....

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yeah it's a 6v replacement for the DTMX type, it will be an ac regulator, the thing to consider is this...

it needs to be connected to ac supply, ie, the ac connection to the rectifier, what kind of rectifier does it have, is it just a crude half wave one like the DT with only 2 connections ?

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Newm"y my voltage reg shows red in and red/white to light switch,,, :eusa_think:

On the US models it is a single connection to the grey wire on mine. red and red/white are the colours for the rectifier on mine.

yeah it's a 6v replacement for the DTMX type, it will be an ac regulator, the thing to consider is this...

it needs to be connected to ac supply, ie, the ac connection to the rectifier, what kind of rectifier does it have, is it just a crude half wave one like the DT with only 2 connections ?

The same half wave rectifier as the DT, Paul. Like this

$%28KGrHqF,%21osF%21KBHF4ieBQRczcvc6g~~6

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try connecting the yellow wire of the regulator to the left hand side of that symbol, and connect the metal body of the regulator to batt negative or a good chassis connection.

you can test it's effectiveness by leaving the yellow unplugged and measuring the battery voltage with the motor running, and repeat after plugging it in.

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So the feed in terminal and sucking any additional volts before it hits the diode? I have a selection of single and double bullets so easy to do.

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So the feed in terminal and sucking any additional volts before it hits the diode? I have a selection of single and double bullets so easy to do.

yeah the diode will only pass the positive half waves and the regulator will keep the peak voltages of these half waves pegged

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Cheers Paul. I will try and do that tomorrow (weather and a trip to Frankie and Bennys permitting) and measure before and after at both the sidelight and the battery at different revs. If that doesn't seem to help, I will connect it to the grey wire and do the same tests.

While I am there I might try and pop out the mag side crank oil seal and fit a new one. There is still an issue with the engine hanging high revs and slowly coming down. I did the WD40 test but it didn't seem to make a difference. I swapped the carb back from the one I got from you to the original one and swapped the filter from the standard box to a ramair foam filter but none of it seemed to make any difference.

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I reckon mines goosed as well!

It's

1: Down on power

2: Bucking and banging on the over run

3: Hanging before settling after high speed runs (motorway)

Did you WD40 your inlet boot, I guess you did

I'm going to start using a smear of blue hylomar at the inlet boot to reed valve connection on mine

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I did, and the barrel base and the carb mounting rubber. Both carb rubbers are new and soft. I will track it down as it can't be anything but an air leak somewhere.

Any thought on what your problem is? It has been cold!

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There is still an issue with the engine hanging high revs and slowly coming down.

This can be caused by your mixture setting also,,,, if ya cant find an air leak.

From nothing to 1/4 throttle is controled by the pilot jet.

If mixture is too lean here the revs will hang high and take a min to come back down.

I'm sure ya know but just reminding ya :eusa_shifty:

EDIT: idle mixture setting should be set on a warm engine. get the highest revs possible then adjust idle speed screw.

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have you tried spraying easystart around the manifold? if there is a leak there, the engine will react

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i'm thinking crank seal too, I could do a leak down test with the rig I made that'll find any leak

That is a good bit of piping Paul.

This can be caused by your mixture setting also,,,, if ya cant find an air leak.

From nothing to 1/4 throttle is controled by the pilot jet.

If mixture is too lean here the revs will hang high and take a min to come back down.

I'm sure ya know but just reminding ya :eusa_shifty:

EDIT: idle mixture setting should be set on a warm engine. get the highest revs possible then adjust idle speed screw.

Cheers Pat. 2 different carbs with 2 different pilot jets but I still can't get it how I want it. I have messed with both pilot screws but it is still not right.

have you tried spraying easystart around the manifold? if there is a leak there, the engine will react

Not sure I want to spray easystart on a hot manifold but a new exhaust gasket won't hurt. I need to spray the exhaust anyway and the exhaust that is on it is NOS. Cost as much as the whole of the YA6.

Really appreciate all of the advice chaps.......................it can be so frustrating!!!!

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Right O people. Stripped out the left hand crank seal and replaced it in situ. this afternoon. Some photos:

Ready for the seal to be pulled.

lhcrank1.jpg

Old seal pulled out, ready for the new seal

lhcrank3.jpg

Old and new seal. The new seal is quite different to the original one.

lhcrank2.jpg

New seal in

lhcrank4.jpg

Coils back on and timing checked.

lhcrank5.jpg

I put the rest of the bits back on, re-set the carb to factory spec, changed the foam ramair filter back to the original airbox and then gave it a healthy kick to start it. It seems to have done the job and revs, returns and idles a lot better. A test ride is needed but I won't be able to do that today.

A little video on my video wall (video 5 on the wall) LINKY

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